WO2016195311A2 - Synthetic water-soluble polymer for dispersion stabilizer of graphene, highly stable colloidal graphene solution comprising same polymer, and graphene hydrogel and graphene aerogel comprising same graphene solution - Google Patents

Synthetic water-soluble polymer for dispersion stabilizer of graphene, highly stable colloidal graphene solution comprising same polymer, and graphene hydrogel and graphene aerogel comprising same graphene solution Download PDF

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WO2016195311A2
WO2016195311A2 PCT/KR2016/005519 KR2016005519W WO2016195311A2 WO 2016195311 A2 WO2016195311 A2 WO 2016195311A2 KR 2016005519 W KR2016005519 W KR 2016005519W WO 2016195311 A2 WO2016195311 A2 WO 2016195311A2
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graphene
group
soluble polymer
synthetic water
solution
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WO2016195311A3 (en
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윤현석
심현우
안기진
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전남대학교산학협력단
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
    • B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
    • B01J20/20—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising free carbon; comprising carbon obtained by carbonising processes
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J3/00—Processes of treating or compounding macromolecular substances
    • C08J3/02—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques
    • C08J3/03—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques in aqueous media
    • C08J3/07—Making solutions, dispersions, lattices or gels by other methods than by solution, emulsion or suspension polymerisation techniques in aqueous media from polymer solutions
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L101/00—Compositions of unspecified macromolecular compounds
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M50/00—Constructional details or processes of manufacture of the non-active parts of electrochemical cells other than fuel cells, e.g. hybrid cells
    • H01M50/40—Separators; Membranes; Diaphragms; Spacing elements inside cells
    • H01M50/489—Separators, membranes, diaphragms or spacing elements inside the cells, characterised by their physical properties, e.g. swelling degree, hydrophilicity or shut down properties
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to graphene, and more specifically, to a synthetic water-soluble polymer for graphene dispersion stabilizer, a highly stable colloidal graphene solution containing the polymer, a graphene hydrogel and a graphene aerogel containing the graphene solution. It is about.
  • Graphene has more than 100 times better electrical conductivity than copper, and more than 10 times more excellent thermal conductivity and superior mechanical properties than copper or aluminum, many studies have been conducted regarding the manufacture of graphene thin films for application to electronic products. have.
  • Graphene is a material that has excellent physical, chemical, and mechanical properties, and it plays a great role in improving the performance and functionality of materials in a wide range of fields besides electrochemical fields through coating methods. There is a lot of research going on.
  • Graphene thin film can be produced by physical and chemical methods.
  • the separation of graphene from graphite is very simple and does not cause defects, so the physical properties are good, but it is difficult to manufacture single-layer graphene and a reaggregation or aggregation occurs after graphene is manufactured. Therefore, there is a problem in that the dispersibility and / or stability in the colloidal form is very low.
  • Graphene manufacturing method using a chemical method uses the principle of separating the graphene sheet from graphite through oxidation and reduction reaction. In the case of using the method of chemical warfare through oxidation and reduction reaction, it is easy to prepare graphene sheets from graphite through oxidation reaction, but the dispersion stability of exfoliated graphene is degraded due to the difficulty of perfect reduction reaction. And the damage of the graphene sheet due to the chemical reaction occurs.
  • a representative method for preparing a single layer of graphene is a chemical vapor deposition method in which carbon atoms are grown on a surface of a metal serving as a catalyst such as copper by using gases such as methane, hydrogen, and argon.
  • this method has to be conducted at high temperature in order to obtain carbon atoms from methane, thereby causing damage to the graphene sheet, which is disadvantageous in terms of cost because it uses a metal such as copper as a catalyst.
  • both single layer graphene and multilayer graphene are used interchangeably under the term graphene, but in a strictly sense, single layer graphene is true graphene, and multilayer graphene corresponds to graphite. It is technically difficult to separate graphene consisting of a single layer of carbon atoms from graphite by physical methods, which are relatively simple approaches. The chemical method developed to overcome this exists in the form of a single layer in the form of graphene oxide, but reaggregation occurs in the reduction process. Synthesis of single-layer graphene production is now easy by chemical vapor deposition to grow carbon atoms on catalysts such as copper. However, it is virtually impossible to produce a stable graphene solution through this method.
  • the electrodeposition from graphene oxide recently proposed by Liyun chen (small, 2011) has the advantage of simpler process and formation of graphene layer directly on the substrate compared to the transfer method.
  • the oxidation process for forming the oxide has a disadvantage that causes the graphene defects after reduction.
  • Graphene on the other hand, is recognized as an attractive electrode material for energy storage and conversion applications when combined with conductive polymer (CP) or inorganic particles.
  • CP conductive polymer
  • the main challenge in the production of graphene / CP composites lies in the formation of graphene layers and the ability to realize nanometer-level diffusion of graphene within the polymer matrix. This is essential for improving the electrochemical properties.
  • Graphene sheets easily aggregate because of the ⁇ - ⁇ interaction. And this agglomeration deteriorates the new properties of graphene.
  • graphene / CP modified or functionalized by chemical treatment is produced by chemical / electrochemical polymerization, covalent / non-covalent bonding and in situ polymerization-reduction / dedoping-redoping processes. It is used for complexes.
  • Graphene oxide (GO) made by dispersing graphite by the conventional chemical method has a lot of impurities and adversely affects the physical properties of the graphene. Therefore, unlike the conventional method, the graphene oxide is dispersed by physical method to change the physical properties of the graphene. There is a high need for a stable single layer graphene solution technology without causing.
  • an object of the present invention is to provide a synthetic water-soluble polymer for graphene dispersion stabilizer having a new structure synthesized by using a water-soluble polymer as a backbone so that the graphene separated from graphite can be uniformly dispersed in a polar solvent.
  • Another object of the present invention is to include a synthetic water-soluble polymer as a graphene dispersion stabilizer to prepare a graphene sheet in a polar solvent, for example, an aqueous solution rather than an organic solvent only through a non-thermal treatment, physical method, and then re-tacking the graphene It can be prevented to provide a high-stable colloidal graphene solution having excellent colloidal dispersibility and stability of the single layer graphene.
  • a synthetic water-soluble polymer as a graphene dispersion stabilizer to prepare a graphene sheet in a polar solvent, for example, an aqueous solution rather than an organic solvent only through a non-thermal treatment, physical method, and then re-tacking the graphene It can be prevented to provide a high-stable colloidal graphene solution having excellent colloidal dispersibility and stability of the single layer graphene.
  • Another object of the present invention can be formed by cross-linking the synthetic water-soluble polymer contained in the high stability colloidal graphene solution while being applicable to various industries throughout the industry to simplify the process and reduce the cost due to the use of low-cost materials It is possible to provide a graphene hydrogel having environmentally friendly properties.
  • Still another object of the present invention is to provide an adsorbent and a conductive separator using graphene aerogel and graphene aerogel prepared by lyophilizing graphene hydrogel.
  • the present invention provides a structure in which at least one hydrophobic functional group is added, at least one hydrophilic functional group is substituted with a hydrophobic functional group, or at least one hydrophobic functional group is added, and at least one hydrophilic functional group is added. It provides a synthetic water-soluble polymer for graphene dispersion stabilizer having a structure substituted with a hydrophobic functional group.
  • the water-soluble polymer is polyvinyl alcohol [Poly (vinyl alcohol)], dextran (Dextran), starch (Starch), polyethylene oxide (Polyethylene oxide), polyacrylamide, polyvinylpyrroli Polyvinyl pyrrolidone, Polyacrylic acid, Polystyrene sulfonic acid [Poly (styrenesulfonic acid)], Polysilic acid [Poly (silicic acid)], Polyphosphoric acid [Poly (phosphoric acid)] Polyethylene sulfonic acid, polymaleic acid, polyamines, poly acrylamide, poly vinylpyrrolidone, polyvinylpyrrolidone ), And polyethylene glycol (Poly Ethylene Glycol) at least one selected from the group consisting of.
  • the hydrophobic functional group is an alkoxy group, fluorenyl group, carbazole group, nitrile group, thiophene group, benzothiophene group, nitro group, aryl group, alkyl group, alkenyl group, alkoxy group, fluorenyl group, Biphenyl group, trifetyl group, terphenyl group, stilbene group, naphthyl group, vinapthyl group, anthracenyl group, phenanthrenyl group, perrylenyl group, tetrasenyl group, chrysenyl group, fluorenyl group, acenaphthacenyl group, tri At least one selected from the group consisting of a heylene group, a fluoroanthene group, a phenyl group and a pyrenyl group.
  • the hydrophobic functional group is a structure comprising an aromatic ring.
  • the present invention also provides a highly stable colloidal graphene solution, characterized in that the graphene is uniformly dispersed in a polar solvent by any one of the above-described synthetic water-soluble polymer for the graphene dispersion stabilizer.
  • the synthetic water-soluble polymer for the graphene dispersion stabilizer is included in 0.1% by weight to 80% by weight.
  • the polar solvent is water.
  • the present invention comprises the steps of preparing a synthetic water-soluble polymer for any one of the above-described graphene dispersion stabilizer; It provides a method for producing a high stability colloidal graphene solution comprising a; and adding the prepared synthetic water-soluble polymer and graphite particles to the polar solvent and performing a physical treatment.
  • the physical treatment is performed for 10 seconds to 120 minutes with any one of ultrasonic, ball milling, homogenizer.
  • the present invention provides a graphene hydrogel formed by crosslinking a synthetic water-soluble polymer contained in the highly stable colloidal graphene solution described above.
  • the crosslinking reaction comprises 90 to 99.9% by weight of the high stability colloidal graphene solution and 0.1 to 10% by weight of the crosslinking agent.
  • preparing a synthetic water-soluble polymer of any one of the above-described graphene dispersion stabilizer Preparing a highly stable colloidal graphene solution by adding the prepared synthetic water-soluble polymer and graphite particles to a polar solvent and then performing physical treatment; It provides a graphene hydrogel manufacturing method comprising a; and adding a crosslinking agent to the prepared graphene solution to crosslink the synthetic water-soluble polymer to form a crosslinking reactant.
  • after forming the crosslinking reactant further includes removing the residual material including the catalyst used in the crosslinking reaction.
  • the present invention provides a graphene airgel formed by removing the water contained in the above-described graphene hydrogel.
  • the moisture is removed by lyophilizing the graphene hydrogel.
  • the present invention provides a separator for an electrode formed by absorbing an electrolyte in the above-described graphene airgel.
  • the present invention also provides an adsorbent comprising the graphene airgel described above.
  • the graphene separated from graphite may be uniformly dispersed in a polar solvent.
  • the high-stable colloidal graphene solution of the present invention includes a synthetic water-soluble polymer that can act as a graphene dispersion stabilizer to produce a graphene sheet in a polar solvent, for example, an aqueous solution rather than an organic solvent only through a non-thermal treatment and physical method. After that, the re-stacking of the graphene can be prevented, so that the single layer graphene has excellent colloidal dispersion and stability.
  • the graphene hydrogel of the present invention can be formed by cross-linking the synthetic water-soluble polymer contained in the high stability colloidal graphene solution while being applicable to various industries throughout the industry, simplifying the process and reducing the cost due to the use of low-cost materials It can enjoy the effect and has environmentally friendly characteristics.
  • the present invention can be applied to a variety of industries, such as graphene aerogel prepared by lyophilizing the graphene hydrogel, in particular it can provide an adsorbent and a conductive separator using a graphene aerogel.
  • Figure 1a is a synthetic schematic diagram of the synthetic water-soluble polymer PH-PVA according to an embodiment of the present invention
  • Figure 1b is a synthetic schematic diagram of the PH-DT is a synthetic water-soluble polymer according to another embodiment of the present invention
  • Figure 1c Synthetic schematic diagram of Py-PVA, a synthetic water-soluble polymer according to another embodiment of the invention
  • Figure 1d is a synthetic schematic diagram of Py-DT is a synthetic water-soluble polymer, according to another embodiment of the present invention
  • Figure 1e is PVA and DT UV visible light absorption spectrum before and after attachment of hydrophobic groups, PH- and Py- functional groups
  • FIG. 1F is UV visible light absorption spectrum of EPP and aminopyrene.
  • Figure 2 is a photograph showing the state of the high stability colloidal graphene solution prepared according to the synthetic water-soluble polymer concentration in another embodiment of the present invention.
  • 3A to 3E are AFM results of the highly stable colloidal graphene solution containing 5% by weight of synthetic water-soluble polymer in another embodiment of the present invention.
  • 4A to 4E are AFM result images of the highly stable colloidal graphene solution containing 10% by weight of synthetic water-soluble polymer in another embodiment of the present invention.
  • 5 is a Raman spectrum result image of the graphene piece obtained by 5 wt% PH-PVA in another embodiment of the present invention.
  • Figure 6a is a photograph showing a process for producing a graphene hydrogel and graphene aerogel from the high stability colloidal graphene solution of the present invention
  • Figure 6b to 6d is a graphene hydrogel obtained in another embodiment of the present invention
  • the results of the experiment on the mechanical properties are photographs.
  • FIG. 7A shows the UV-visible absorption spectra of methylene blue at different concentrations
  • FIG. 7B is a calibration curve derived from the spectrum of FIG. 7A
  • FIG. 7C shows the present invention in a methylene blue solution in another embodiment of the invention.
  • the photo shows the color change and UV visible absorption spectrum before and after graphene airgel treatment.
  • FIG. 8 is a graph showing typical constant current charge / discharge and long term cycling performances recorded at 0.5 current density g ⁇ 1 of a solid state supercapacitor including the separator for electrodes of the present invention in another embodiment of the present invention.
  • the present invention is a synthetic water-soluble polymer for graphene dispersion stabilizer of a novel structure synthesized by using a water-soluble polymer as a backbone so that the graphene separated from the graphite can be uniformly dispersed in a polar solvent, the synthetic water-soluble polymer It is possible to prevent re-tacking of the graphene by including a high stability colloidal graphene solution having excellent colloidal dispersibility and stability of the graphene, since the hydrogel formed from the graphene solution and various applications including the same In view of this, the present invention will be described.
  • exfoliation of graphite using intercalants especially methods of separating graphene from conventional graphite, always leaves residual inserts in the separated graphene pieces.
  • the removal of polymer inserts is more difficult than the removal of very small molecules and has a high probability of inhibiting the usefulness of the synthesized graphene.
  • the present invention solves these problems to obtain an aqueous acid solution of the graphene fragment stabilized by the synthetic water-soluble polymer, and this aqueous acid solution does not remove the synthetic water-soluble polymer used as an insert to prevent retacking of the graphene.
  • Its technical features are directly applicable. That is, it is because crosslinking the synthetic water-soluble polymer contained in the aqueous acid solution to form a hydrogel, and can be applied by making an aerogel from the hydrogel.
  • the synthetic water-soluble polymer for the graphene dispersion stabilizer of the present invention has a structure in which at least one hydrophobic functional group is added, at least one hydrophilic functional group is substituted with a hydrophobic functional group, or at least one hydrophobic functional group is added to one of the hydrophilic functional groups. Two or more have a structure substituted with a hydrophobic functional group.
  • the synthetic water-soluble polymer having one or more hydrophobic functional groups introduced into the water-soluble polymer has the advantage of being easily dissolved in a polar solvent, especially an aqueous solution, and easily combined with graphene through the introduced hydrophobic functional groups. Therefore, when a graphene sheet is formed from graphite by physical treatment in an aqueous solution state, for example, a polar solvent in which the synthetic water-soluble polymer of the present invention is dissolved, the synthetic water-soluble polymer is sandwiched between the graphene sheets, ⁇ - ⁇ of the graphene sheet. Since the interaction can be prevented to prevent re-tacking of the graphene sheet, a highly stable colloidal graphene solution in which graphene is uniformly dispersed can be obtained.
  • the water-soluble polymer can be used all known water-soluble polymer, polyvinyl alcohol [Poly (vinyl alcohol)], dextran (Dextran), starch (Starch), polyethylene oxide (polyethylene oxide), polyacrylamide (Polyacrylamide) , Polyvinylpyrrolidone, polyacrylic acid, polystyrene sulfonic acid [Poly (styrenesulfonic acid)], polysilic acid [Poly (silicic acid)], polyphosphoric acid [Poly (phosphoric acid)], poly (ethylene sulfonic acid), poly (maleic acid), polyamines, poly acrylamide, polyvinylpyrrolye It may be at least one selected from the group consisting of polyvinyl pyrrolidone, and polyethylene glycol (polyethylene glycol).
  • the hydrophobic functional groups introduced into the water-soluble polymer are alkoxy, fluorenyl, carbazole, nitrile, thiophene, benzothiophene, nitro, aryl, alkyl, alkenyl, alkoxy, fluorenyl, Biphenyl group, trifetyl group, terphenyl group, stilbene group, naphthyl group, vinapthyl group, anthracenyl group, phenanthrenyl group, perrylenyl group, tetrasenyl group, chrysenyl group, fluorenyl group, acenaphthacenyl group, tri It may be at least one selected from the group consisting of a heylene group, a fluoroanthene group, a phenyl group, and a pyrenyl group.
  • the hydrophobic functional group is a structure containing an aromatic ring.
  • the high-stable colloidal graphene solution of the present invention is that the graphene is uniformly dispersed in the polar solvent by the synthetic water-soluble polymer for graphene dispersion stabilizer, the synthetic water-soluble polymer for graphene dispersion stabilizer 0.1% by weight to 80% It was experimentally confirmed that the most stable stably colloidal form can be maintained when it contains%, graphene 0.005 to 40% by weight, and the remaining weight of the solvent.
  • the highly stable colloidal graphene solution of the present invention can be easily prepared by performing physical treatment for 1 minute to 60 minutes after adding a soluble conductive polymer solution and graphite to water or an organic solvent.
  • the physical treatment may include sonication or ball milling, and may separate single layer graphene from graphite.
  • the method for preparing a highly stable colloidal graphene solution of the present invention comprises the steps of preparing a synthetic water-soluble polymer for the graphene dispersion stabilizer and adding the prepared synthetic water-soluble polymer and graphite particles to a polar solvent and then performing physical treatment. It includes.
  • the graphite particles mean that the graphene is substantially thick as the raw material of graphene, and the thickness of the graphene is agglomerated in multiple layers, and includes pure graphite or expanded graphite.
  • Physical treatment may include sonication or ball milling or homogenizer, and may separate graphene from graphite and expanded graphite.
  • the physical treatment may be carried out for 10 seconds to 120 minutes, preferably 1 minute to 60 minutes, more preferably 10 minutes to 30 minutes, through the physical treatment to a simple but defect-free graphene Can be separated.
  • the graphene hydrogel of the present invention is formed by crosslinking the synthetic water-soluble polymer contained in the high stability colloidal graphene solution, the crosslinking reaction is 90 to 99.9% by weight of the high stability colloidal graphene solution and 0.1 to 10 crosslinking agent It may comprise a weight percent.
  • a crosslinking agent used in the present invention any known crosslinking agent capable of crosslinking a water-soluble polymer may be used. In the examples described below, Glutaraldehyde was used under a sulfuric acid catalyst.
  • the graphene airgel of the present invention is formed by removing the water contained in the graphene hydrogel, the water can be removed by any known method, in particular can be removed by lyophilizing the graphene hydrogel.
  • the graphene airgel formed as described above is applicable to various products such as adsorbents or conductive separators.
  • Phenoxy-PVA was prepared by reacting EPP (1,2-epoxy ?? phonoxypropane) to introduce a hydrophobic group into PVA, which is a water-soluble polymer.
  • Phenoxy-Dextran was prepared by reacting EPP as follows to introduce a hydrophobic group into a water-soluble polymer, Dextran.
  • the synthetic procedure of PH-DT is similar to PH-PVA.
  • Pyrene-PVA (Py-PVA) was prepared by reacting as follows to introduce a hydrophobic group to PVA, which is a water-soluble polymer.
  • Pyrene-Dextran (Py-DT) was prepared by reacting as follows to introduce a hydrophobic group to Dextran, which is a water-soluble polymer.
  • UVvisible spectroscopy was performed to confirm whether hydrophobic groups were introduced to the synthetic water-soluble polymers PH-PVA, PH-DT, Py-PVA, and Py-DT obtained in Example 1, and the results are shown in FIG. 1E.
  • PH-PVA, Py-PVA, and Py-DT obtained in Example 1 were added to 5 mL of distilled water at 5% by weight and 10% by weight, respectively, and then dissolved. After complete dissolution, 0.0009 g of exfoliated graphite (Sigma-Aldrich) was added and dispersed for 30 minutes at 60% amplitude using ultrasonic wave. The final black solution was then centrifuged at 1,000 rpm for 10 minutes to separate extra impurities, including unstable graphene or residual graphite.
  • Example 2 In the six high-stable colloidal graphene solutions obtained in Example 2 using atomic force microscopy (AFM), the characteristics of the graphene pieces dispersed in the aqueous solution were observed. As a result, 5% by weight of the image was shown in FIGS. 3A to 3E and 10% by weight. % Is shown in FIGS. 4A-4E. 3A and 4A are PVA, 3b and 4b are PH-PVA, 3c and 4c are Py-PVA, 3d and 4d are DT, and 3e and 4e are Py-DT.
  • 3A and 4A are PVA
  • 3b and 4b are PH-PVA
  • 3c and 4c are Py-PVA
  • 3d and 4d are DT
  • 3e and 4e are Py-DT.
  • the more opaque black solution contains many graphene fragments of different sizes and thicknesses.
  • the lamination number and size of the graphene sheet is determined to depend on the chemical structure and concentration of the synthetic water-soluble polymer. It was also observed that native PVA at the same concentration yielded better dispersed graphene pieces of larger size than native DT. In particular, at 10% by weight, the concentration of the synthetic water-soluble polymer, it can be observed that all the graphene pieces appear thin and large.
  • the 2D peak changes according to the number of stacked layers of graphene.
  • the change in shape of the 2D peak confirms the stacking of graphene layers in the AB array in the flakes.
  • Example 2 0.56 g of Py-PVA obtained in Example 1 was added to 5 mL of distilled water and then dissolved. After complete dissolution, 0.0009 g of exfoliated graphite was added and dispersed for 30 minutes using ultrasonic to obtain a highly stable colloidal graphene solution. Thereafter, 1 wt% (0.011 mL) of Glutaraldehyde as a crosslinking agent was added to 5 ml of the highly stable colloidal graphene solution, and immediately after stirring, 0.08 MH 2 SO 4 (2.4 mL) was added as a catalyst. Immediately after stirring, the mixture was poured into a mold and the crosslinking reaction was continued for 12 hours at room temperature (temperature range within 80 ° C). After gelation until the pH becomes constant, the hydrogel was washed with excess distilled water to remove residual substances such as sulfuric acid, and the hydrogel as shown in FIG. 6a was obtained.
  • Graphene hydrogel is a form in which graphene fragments are inserted into a polymer chain network by cross-linking of Py-PVA, a synthetic water-soluble polymer dispersed in a solution.
  • FIG. 6c shows the expanded state and the contracted state of the graphene hydrogel when water-based, it can be seen that the graphene hydrogel can be significantly changed in volume by the absorption of water.
  • FIG. 6D shows visible holes formed in the hydrogel.
  • the crosslink density (NC- 1 ) of the hydrogel was 0.08.
  • Example 3 The hydrogel obtained in Example 3 was subjected to lyophilization which was treated with FTS Dura-Stop / Dura-Top freeze dryer (Kinetics, FTS) for 24 hours in vacuo at -45 ° C. to completely remove the moisture of the hydrogel, thereby obtaining an airgel.
  • FTS FTS Dura-Stop / Dura-Top freeze dryer
  • FIG. 7A is the UV-visible absorption spectra of methylene blue at different concentrations
  • FIG. 7B is a calibration curve derived from the spectrum of FIG. 7A.
  • the blue color of the methylene blue solution (adsorption of methylene blue at 665 nm) disappeared after treatment with graphene aerogels.
  • Methylene blue a heteroaromatic compound, is expected to adsorb on the graphene fragments contained in graphene airgel spontaneously by high chemical affinity. Therefore, it can be seen that the graphene airgel of the present invention shows an effective removal efficiency of almost 100% with respect to the dye present in the aqueous solution.
  • the airgel prepared in Example 4 was immersed in 1 MH 2 SO 4 electrolyte for 1 hour to prepare a membrane for the electrode. That is, since the graphene airgel of the present invention has a strong mechanical property, it is possible to prepare an electrode separator by containing an acidic electrolyte (H 2 SO 4 ) in the gel.
  • an acidic electrolyte H 2 SO 4
  • CNF electrodes Two carbon nanofiber (CNF) electrodes were made of the same size (8mm ⁇ 15mm).
  • the separator for electrodes obtained in Example 5 was assembled between CNF electrode materials to prepare a solid supercapacitor as follows. Two stainless steel foils (0.001 in thick) were used as the current collector and finally the supercapacitor was wrapped in a polypropylene film. PVA-only / H 2 SO 4 gel electrolyte was used as a control. Constant current charge / discharge experiments were performed on these, and the results are shown in FIG. 8. The constant current charge / discharge curves yielded a current density of 0.5 g ⁇ 1 .
  • the control group in PVA-only / gel electrolyte (84.2 ⁇ 5.2 Fg - 1) use of a separator for an electrode of the present invention as compared to (107.5 ⁇ 3.1 Fg - 1) has a higher capacity, and 10,000 cycles It can be seen that the above excellent long-term cycle stability is allowed. This result is expected to be due to the graphene included in the electrode separator of the present invention improves the ionic conductivity of the gel.

Abstract

The present invention relates to graphene, and more specifically, to a synthetic water-soluble polymer for a dispersion stabilizer of graphene, a highly stable colloidal graphene solution comprising the same polymer, and graphene hydrogel and graphene aerogel comprising the same graphene solution.

Description

그래핀 분산안정제용 합성수용성고분자, 그 고분자를 포함하는 고안정성 콜로이드 그래핀용액, 그 그래핀용액을 포함하는 그래핀하이드로겔 및 그래핀에어로겔Synthetic water-soluble polymer for graphene dispersion stabilizer, highly stable colloidal graphene solution containing the polymer, graphene hydrogel and graphene aerogel containing the graphene solution
본 발명은 그래핀에 관한 것으로, 보다 구체적으로는 그래핀 분산안정제용 합성수용성고분자, 그 고분자를 포함하는 고안정성 콜로이드 그래핀용액, 그 그래핀용액을 포함하는 그래핀하이드로겔 및 그래핀에어로겔에 관한 것이다. The present invention relates to graphene, and more specifically, to a synthetic water-soluble polymer for graphene dispersion stabilizer, a highly stable colloidal graphene solution containing the polymer, a graphene hydrogel and a graphene aerogel containing the graphene solution. It is about.
그래핀은 구리의 100배 이상의 우수한 전기전도도를 가지며, 구리 또는 알루미늄의 10배 이상의 우수한 열전도도 및 우수한 기계적 물성으로 인하여 전자제품에의 적용을 위하여 그래핀 박막의 제조와 관련하여 많은 연구가 진행되고 있다. Graphene has more than 100 times better electrical conductivity than copper, and more than 10 times more excellent thermal conductivity and superior mechanical properties than copper or aluminum, many studies have been conducted regarding the manufacture of graphene thin films for application to electronic products. have.
그래핀은 물리적, 화학적, 기계적으로 매우 우수한 특성을 갖는 물질로써 코팅 등의 방식을 통해 전기화학적인 분야 이외에도 매우 폭 넓은 분야에서 소재의 성능을 향상시키고 기능성을 부여하는데 큰 역할을 하기 때문에 제조와 응용에 관련하여 많은 연구가 진행되고 있다.Graphene is a material that has excellent physical, chemical, and mechanical properties, and it plays a great role in improving the performance and functionality of materials in a wide range of fields besides electrochemical fields through coating methods. There is a lot of research going on.
그래핀 박막은 물리적인 방법과 화학적인 방법으로 제조될 수 있다. 물리적인 방법의 경우 그래파이트로부터 그래핀을 분리시키는 것이 매우 간단하고 결함을 발생시키지 않아 물성이 좋은 반면, 단일층 그래핀을 제조하기 힘들며 그래핀이 제조된 후 재응집 현상(restacking or aggregation)이 발생하여 콜로이드 형태 시 그 분산성 및/또는 안정성이 매우 낮은 문제점이 존재한다.Graphene thin film can be produced by physical and chemical methods. In the physical method, the separation of graphene from graphite is very simple and does not cause defects, so the physical properties are good, but it is difficult to manufacture single-layer graphene and a reaggregation or aggregation occurs after graphene is manufactured. Therefore, there is a problem in that the dispersibility and / or stability in the colloidal form is very low.
물리적인 방법의 경우 물리적인 힘을 가하여 그래파이트로부터 그래핀을 박리시키는 원리를 이용한다. 단순한 물리적인 방법을 이용하는 경우에는 공정이 간단하고 결함을 발생시키지 않는 반면, 지속적인 단일층의 그래핀을 제조하기 어렵고, 박리된 그래핀의 재응집 현상이 발생하여 그래핀의 분산안정성이 낮다는 문제점이 있으며, 대부분의 용매가 유기용매이기 때문에 비용적인 측면에서 대량생산이 어렵다는 단점이 있다. In the case of the physical method, the principle of peeling graphene from graphite by applying a physical force is used. In the case of using a simple physical method, the process is simple and does not cause defects, while it is difficult to manufacture a continuous single layer of graphene, and re-aggregation of exfoliated graphene occurs, resulting in low dispersion stability of graphene. There is a disadvantage in that mass production is difficult in terms of cost because most solvents are organic solvents.
화학적인 방법을 이용한 그래핀 제조방법은 산화와 환원반응을 통해 그래파이트로부터 그래핀 시트를 분리해 내는 원리를 이용한다. 산화, 환원반응을 통한 화학전인 방법을 이용하는 경우에는 산화반응을 통해 그래파이트로부터 그래핀 시트를 제조하는데 용이하지만, 완벽한 환원반응이 이루어지기 어렵기 때문에 박리된 그래핀의 분산안정성이 저하되어 재응집이 일어난다는 것과 화학반응으로 인한 그래핀 시트의 손상이 발생한다는 단점이 있다. Graphene manufacturing method using a chemical method uses the principle of separating the graphene sheet from graphite through oxidation and reduction reaction. In the case of using the method of chemical warfare through oxidation and reduction reaction, it is easy to prepare graphene sheets from graphite through oxidation reaction, but the dispersion stability of exfoliated graphene is degraded due to the difficulty of perfect reduction reaction. And the damage of the graphene sheet due to the chemical reaction occurs.
현재 단일층의 그래핀을 제조하는 대표적인 방법은 메탄, 수소, 아르곤 등의 가스를 이용하여 구리등과 같은 촉매 의 역할을 하는 금속의 표면에서 탄소 원자를 성장시키는 화학적기상증착법이다. 그러나 이 방법은 메탄에서 탄소원자를 얻기 위하여 고온에서 진행되어야 함으로 그에 따른 그래핀 시트의 손상이 발생하며, 촉매로써 구리와 같은 금속을 사용하기 때문에 비용적인 측면에서 단점이 있다.Currently, a representative method for preparing a single layer of graphene is a chemical vapor deposition method in which carbon atoms are grown on a surface of a metal serving as a catalyst such as copper by using gases such as methane, hydrogen, and argon. However, this method has to be conducted at high temperature in order to obtain carbon atoms from methane, thereby causing damage to the graphene sheet, which is disadvantageous in terms of cost because it uses a metal such as copper as a catalyst.
이러한 문제점들로 인해 그래핀이 가지고 있는 물리적, 화학적, 기계적으로 매우 우수한 특성에도 불구하고 재현성, 비용 측면 등에서의 문제로인해 그래핀의 응용이 제한되고 있기 때문에, 그래핀의 손상과 제조의 비용적 측면의 부담이 최소화되고 대량생산이 가능한 그래핀 제조 기술에 대한 필요성이 높은 실정이다. Because of these problems, despite the excellent physical, chemical and mechanical properties of graphene, the application of graphene is limited due to problems in terms of reproducibility and cost. There is a high need for graphene manufacturing technology capable of minimizing side burden and mass production.
종래에는 단일층 그래핀과 멀티레이어 그래핀을 모두 그래핀이라는 용어로 혼용해서 사용하고 있으나, 엄밀한 의미에서 단일층 그래핀이 진정한 그래핀이고, 멀티레이어 그래핀은 그래파이트에 해당한다. 비교적 간단한 접근법인 물리적인 방법을 통해 그래파이트로부터 탄소 원자 한 층으로 구성된 그래핀을 분리해 내기는 기술적으로 상당히 어려운 점이 많다. 이를 극복하기 위해 개발된 화학적인 방법 또한 그래핀 산화물 형태에서는 단일층 형태로 존재하지만 환원 과정에서 재응집이 일어난다. 현재 단일층 그래핀 생산이 용이한 합성법은 구리와 같은 촉매 상에서 탄소 원자를 성장시키는 화학증착법이다. 그러나 이 방법을 통해 안정성 있는 그래핀 용액을 제조하는 것은 사실상 불가능하다.Conventionally, both single layer graphene and multilayer graphene are used interchangeably under the term graphene, but in a strictly sense, single layer graphene is true graphene, and multilayer graphene corresponds to graphite. It is technically difficult to separate graphene consisting of a single layer of carbon atoms from graphite by physical methods, which are relatively simple approaches. The chemical method developed to overcome this exists in the form of a single layer in the form of graphene oxide, but reaggregation occurs in the reduction process. Synthesis of single-layer graphene production is now easy by chemical vapor deposition to grow carbon atoms on catalysts such as copper. However, it is virtually impossible to produce a stable graphene solution through this method.
그래핀 층 형성 방법 중 가장 널리 쓰이고 있는 방법은 이종학(Adv. Mater, 2010)이 제시한 여과 및 전달 방법(Filtration and transfer method)이다. 그러나 그래핀의 여과시 AAO라는 특수한 맴브레인을 요구하고, 공정단계가 많고, 원하는 기판에 전달을 해야 한다는 단점이 있다. 전달 공정 시 형성된 그래핀 층의 부서짐이 일어나기 쉽고, 전달 없이 파우더 상으로 얻는 경우에는 전극에 로딩하기 위해 바인더가 요구되는 단점이 있다.The most widely used method of graphene layer formation is the Filtration and Transfer method proposed by Heterology (Adv. Mater, 2010). However, filtration of graphene requires a special membrane called AAO, many process steps, and delivery to a desired substrate. The breakdown of the graphene layer formed during the transfer process is liable to occur, and when obtained in powder form without transfer, a binder is required for loading on the electrode.
최근 Liyun chen(small, 2011)이 제안한 그래핀 옥사이드로부터의 전착은 전달 방법에 비해 공정이 간단하고 기판에 직접 그래핀 층을 형성한다는 장점이 있다. 그러나 옥사이드를 형성하기 위한 산화공정은 환원 후 그래핀 결점의 원인이 되는 단점이 있다.The electrodeposition from graphene oxide recently proposed by Liyun chen (small, 2011) has the advantage of simpler process and formation of graphene layer directly on the substrate compared to the transfer method. However, the oxidation process for forming the oxide has a disadvantage that causes the graphene defects after reduction.
한편, 그래핀은 전도성고분자(Conducting Polymer: CP) 또는 무기 입자와 화합되는 경우에 에너지 저장 및 컨버젼 어플리케이션을 위한 매력적인 전극 물질로 인식되고 있다. 그래핀/CP 복합물의 제조에서의 주된 도전은 그래핀 층의 형성 및 폴리머 매트릭스 내의 그래핀의 나노미터 수준 확산을 실현하는 능력에 있다. 이는 전기화학적 특성을 개선하는데 필수적이다. 그래핀 시트는 π-π 상호작용 때문에 쉽게 응집한다. 그리고 이 응집은 그래핀의 새로운 특성을 좋지 않게 한다.Graphene, on the other hand, is recognized as an attractive electrode material for energy storage and conversion applications when combined with conductive polymer (CP) or inorganic particles. The main challenge in the production of graphene / CP composites lies in the formation of graphene layers and the ability to realize nanometer-level diffusion of graphene within the polymer matrix. This is essential for improving the electrochemical properties. Graphene sheets easily aggregate because of the π-π interaction. And this agglomeration deteriorates the new properties of graphene.
이러한 문제들을 극복하기 위해, 화학 처리에 의해 개조되거나 작용기화된 그래핀이 화학/전기화학 중합, 공유/비공유 결합 및 인시츄 중합-환원/디도핑-리도핑 과정에 의해 제조된 그래핀/CP 복합체를 위해 사용되고 있다.In order to overcome these problems, graphene / CP modified or functionalized by chemical treatment is produced by chemical / electrochemical polymerization, covalent / non-covalent bonding and in situ polymerization-reduction / dedoping-redoping processes. It is used for complexes.
기존의 화학적 방법으로 그래파이트를 분산시켜 만든 그래핀 옥사이드(GO)는 불순물이 많고 그래핀의 물성에 좋지 않은 영향을 미치므로, 기존 방법과 달리 그래핀을 물리적방법으로 분산시킴으로써 그래핀의 물성 변화를 일으키지 않으면서도 안정성 있는 단일층 그래핀 용액 기술에 대한 필요성이 높은 실정이다.Graphene oxide (GO) made by dispersing graphite by the conventional chemical method has a lot of impurities and adversely affects the physical properties of the graphene. Therefore, unlike the conventional method, the graphene oxide is dispersed by physical method to change the physical properties of the graphene. There is a high need for a stable single layer graphene solution technology without causing.
따라서, 본 발명의 목적은 그래파이트에서 분리된 그래핀이 극성용매에서 균일하게 분산된 상태를 유지할 수 있도록 수용성고분자를 백본으로 하여 합성된 새로운 구조의 그래핀분산안정제용 합성수용성고분자를 제공하는 것이다. Accordingly, an object of the present invention is to provide a synthetic water-soluble polymer for graphene dispersion stabilizer having a new structure synthesized by using a water-soluble polymer as a backbone so that the graphene separated from graphite can be uniformly dispersed in a polar solvent.
본 발명의 다른 목적은 합성수용성고분자를 그래핀 분산안정제로 포함함으로써 비열처리, 물리적인 방식만을 통해 유기 용매가 아닌 극성용매 예를 들어 수용액상에서 그래핀 시트를 제조한 후, 그래핀의 리스태킹을 방지할 수 있어 단일층 그래핀의 콜로이드 분산성 및 안정성이 탁월한 특성을 갖는 고안정성 콜로이드 그래핀용액을 제공하는 것이다.Another object of the present invention is to include a synthetic water-soluble polymer as a graphene dispersion stabilizer to prepare a graphene sheet in a polar solvent, for example, an aqueous solution rather than an organic solvent only through a non-thermal treatment, physical method, and then re-tacking the graphene It can be prevented to provide a high-stable colloidal graphene solution having excellent colloidal dispersibility and stability of the single layer graphene.
본 발명의 또 다른 목적은 산업전반에 걸쳐 다양하게 적용이 가능하면서도 고안정성 콜로이드 그래핀용액에 포함된 합성수용성고분자를 가교시킴으로써 형성할 수 있어 공정의 단순화 및 저가형 소재 사용으로 인한 비용감소 효과를 누릴 수 있어 환경친화적인 특성을 갖는 그래핀하이드로겔을 제공하는 것이다. Another object of the present invention can be formed by cross-linking the synthetic water-soluble polymer contained in the high stability colloidal graphene solution while being applicable to various industries throughout the industry to simplify the process and reduce the cost due to the use of low-cost materials It is possible to provide a graphene hydrogel having environmentally friendly properties.
본 발명의 또 다른 목적은 그래핀하이드로겔을 동결건조하여 제조된 그래핀에어로겔 및 그래핀 에어로겔을 활용한 흡착제 및 전도성 분리막을 제공하는 것이다.Still another object of the present invention is to provide an adsorbent and a conductive separator using graphene aerogel and graphene aerogel prepared by lyophilizing graphene hydrogel.
본 발명의 목적은 이상에서 언급한 목적으로 제한되지 않으며, 언급되지 않은 또 다른 목적들은 아래의 기재로부터 당업자에게 명확하게 이해될 수 있을 것이다.The object of the present invention is not limited to the above-mentioned object, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.
상술된 목적을 달성하기 위하여, 본 발명은 1개 이상의 소수성작용기가 부가된 구조, 친수성작용기 중 1개 이상이 소수성작용기로 치환된 구조 또는 1개 이상의 소수성작용기가 부가되고 친수성작용기 중 1개 이상이 소수성작용기로 치환된 구조를 갖는 그래핀 분산안정제용 합성수용성고분자를 제공한다. In order to achieve the above object, the present invention provides a structure in which at least one hydrophobic functional group is added, at least one hydrophilic functional group is substituted with a hydrophobic functional group, or at least one hydrophobic functional group is added, and at least one hydrophilic functional group is added. It provides a synthetic water-soluble polymer for graphene dispersion stabilizer having a structure substituted with a hydrophobic functional group.
바람직한 실시예에 있어서, 상기 수용성고분자는 폴리비닐알코올[Poly(vinyl alcohol)], 덱스트란(Dextran), 전분(Starch), 폴리에틸렌옥사이드(Polyethylene oxide), 폴리아크릴아마이드(Polyacrylamide), 폴리비닐피롤리돈(Polyvinyl pyrrolidone), 폴리아크릴릭엑시드(Polyacrylic acid), 폴리 스타이렌설포닉엑시드[Poly(styrenesulfonic acid)], 폴리실릭익엑시드[Poly(silicic acid)], 폴리포스포릭엑시드[Poly(phosphoric acid)], 폴리에틸렌설포닉엑시드[Poly(ethylene sulfonic acid)], 폴리말레익엑시드[Poly(maleic acid)], 폴리아마인스(Polyamines), 폴리아크릴아마이드(Poly acrylamide), 폴리비닐피롤리돈(Poly vinyl pyrrolidone), 및 폴리에틸렌글리콜(Poly Ethylene Glycol)로 구성된 그룹에서 선택된 1개 이상이다. In a preferred embodiment, the water-soluble polymer is polyvinyl alcohol [Poly (vinyl alcohol)], dextran (Dextran), starch (Starch), polyethylene oxide (Polyethylene oxide), polyacrylamide, polyvinylpyrroli Polyvinyl pyrrolidone, Polyacrylic acid, Polystyrene sulfonic acid [Poly (styrenesulfonic acid)], Polysilic acid [Poly (silicic acid)], Polyphosphoric acid [Poly (phosphoric acid)] Polyethylene sulfonic acid, polymaleic acid, polyamines, poly acrylamide, poly vinylpyrrolidone, polyvinylpyrrolidone ), And polyethylene glycol (Poly Ethylene Glycol) at least one selected from the group consisting of.
바람직한 실시예에 있어서, 상기 소수성 작용기는 알콕시기, 플루오레닐기, 카바졸기, 니트릴기, 티오펜기, 벤조티오펜기, 니트로기, 아릴기, 알킬기, 알케닐기, 알콕시기, 플루오레닐기, 비페닐기, 트라이페틸기, 터페닐기, 스틸벤기, 나프틸기, 비나프틸기, 안트라세닐기, 페난트레닐기, 페릴레닐기, 테트라세닐기, 크라이세닐기, 플로오레닐기, 아세나프타세닐기, 트리헤닐렌기, 플로오란텐기, 페닐기, 파이레닐기로 구성된 그룹에서 선택된 1개 이상이다. In a preferred embodiment, the hydrophobic functional group is an alkoxy group, fluorenyl group, carbazole group, nitrile group, thiophene group, benzothiophene group, nitro group, aryl group, alkyl group, alkenyl group, alkoxy group, fluorenyl group, Biphenyl group, trifetyl group, terphenyl group, stilbene group, naphthyl group, vinapthyl group, anthracenyl group, phenanthrenyl group, perrylenyl group, tetrasenyl group, chrysenyl group, fluorenyl group, acenaphthacenyl group, tri At least one selected from the group consisting of a heylene group, a fluoroanthene group, a phenyl group and a pyrenyl group.
바람직한 실시예에 있어서, 상기 소수성 작용기는 아로마틱 링을 포함하는 구조이다. In a preferred embodiment, the hydrophobic functional group is a structure comprising an aromatic ring.
또한, 본 발명은 상술된 어느 하나의 그래핀 분산안정제용 합성수용성고분자에 의해 그래핀이 극성용매에 균일하게 분산된 것을 특징으로 하는 고안정성 콜로이드 그래핀 용액을 제공한다. The present invention also provides a highly stable colloidal graphene solution, characterized in that the graphene is uniformly dispersed in a polar solvent by any one of the above-described synthetic water-soluble polymer for the graphene dispersion stabilizer.
바람직한 실시예에 있어서, 상기 그래핀 분산안정제용 합성수용성고분자는 0.1중량% 내지 80중량%로 포함된다. In a preferred embodiment, the synthetic water-soluble polymer for the graphene dispersion stabilizer is included in 0.1% by weight to 80% by weight.
바람직한 실시예에 있어서, 상기 극성용매는 물이다. In a preferred embodiment, the polar solvent is water.
또한, 본 발명은 상술된 어느 하나의 그래핀 분산안정제용 합성수용성고분자를 준비하는 단계; 및 상기 준비된 합성수용성고분자와 흑연입자를 극성용매에 첨가한 후 물리적 처리를 수행하는 단계;를 포함하는 고안정성 콜로이드 그래핀용액 제조방법을 제공한다. In addition, the present invention comprises the steps of preparing a synthetic water-soluble polymer for any one of the above-described graphene dispersion stabilizer; It provides a method for producing a high stability colloidal graphene solution comprising a; and adding the prepared synthetic water-soluble polymer and graphite particles to the polar solvent and performing a physical treatment.
바람직한 실시예에 있어서, 상기 물리적 처리는 초음파, 볼밀링, 호모지나이저 중 어느 하나로 10초 내지 120분 동안 이루어진다. In a preferred embodiment, the physical treatment is performed for 10 seconds to 120 minutes with any one of ultrasonic, ball milling, homogenizer.
본 발명은 상술된 고안정성 콜로이드 그래핀 용액에 포함된 합성수용성고분자를 가교반응시켜 형성된 그래핀 하이드로겔을 제공한다. The present invention provides a graphene hydrogel formed by crosslinking a synthetic water-soluble polymer contained in the highly stable colloidal graphene solution described above.
바람직한 실시예에 있어서, 상기 가교반응은 상기 고안정성 콜로이드 그래핀 용액 90 내지 99.9중량% 및 가교제 0.1 내지 10중량%를 포함하여 이루어진다. In a preferred embodiment, the crosslinking reaction comprises 90 to 99.9% by weight of the high stability colloidal graphene solution and 0.1 to 10% by weight of the crosslinking agent.
또한, 상술된 어느 한 항의 그래핀 분산안정제용 합성수용성고분자를 준비하는 단계; 상기 준비된 합성수용성고분자와 흑연입자를 극성용매에 첨가한 후 물리적 처리를 수행하여 고안정성 콜로이드 그래핀용액을 준비하는 단계; 및 상기 준비된 그래핀용액에 가교제를 첨가하여 상기 합성수용성고분자를 가교반응시켜 가교반응물을 형성하는 단계;를 포함하는 그래핀 하이드로겔 제조방법을 제공한다. In addition, preparing a synthetic water-soluble polymer of any one of the above-described graphene dispersion stabilizer; Preparing a highly stable colloidal graphene solution by adding the prepared synthetic water-soluble polymer and graphite particles to a polar solvent and then performing physical treatment; It provides a graphene hydrogel manufacturing method comprising a; and adding a crosslinking agent to the prepared graphene solution to crosslink the synthetic water-soluble polymer to form a crosslinking reactant.
바람직한 실시예에 있어서, 상기 가교반응물을 형성한 후 가교반응시 사용된 촉매를 포함한 잔여물질을 제거하는 단계를 더 포함한다. In a preferred embodiment, after forming the crosslinking reactant further includes removing the residual material including the catalyst used in the crosslinking reaction.
또한, 본 발명은 상술된 그래핀 하이드로겔에 포함된 수분을 제거하여 형성된 그래핀 에어로겔을 제공한다. In addition, the present invention provides a graphene airgel formed by removing the water contained in the above-described graphene hydrogel.
바람직한 실시예에 있어서, 상기 수분은 상기 그래핀 하이드로겔을 동결건조하여 제거된다. In a preferred embodiment, the moisture is removed by lyophilizing the graphene hydrogel.
또한, 본 발명은 상술된 그래핀 에어로겔에 전해질을 흡수시켜 형성된 전극용 분리막을 제공한다.In addition, the present invention provides a separator for an electrode formed by absorbing an electrolyte in the above-described graphene airgel.
또한, 본 발명은 상술된 그래핀 에어로겔을 포함하는 흡착제를 제공한다. The present invention also provides an adsorbent comprising the graphene airgel described above.
먼저, 본 발명의 그래핀분산안정제용 합성수용성고분자에 의하면 그래파이트에서 분리된 그래핀이 극성용매에서 균일하게 분산된 상태를 유지할 수 있다. First, according to the synthetic water-soluble polymer for the graphene dispersion stabilizer of the present invention, the graphene separated from graphite may be uniformly dispersed in a polar solvent.
또한, 본 발명의 고안정성 콜로이드 그래핀용액은 그래핀분산안정제로 작용할 수 있는 합성수용성고분자를 포함함으로써 비열처리, 물리적인 방식만을 통해 유기 용매가 아닌 극성용매 예를 들어 수용액상에서 그래핀 시트를 제조한 후, 그래핀의 리스태킹을 방지할 수 있어 단일층 그래핀의 콜로이드 분산성 및 안정성이 탁월한 특성을 갖는다.In addition, the high-stable colloidal graphene solution of the present invention includes a synthetic water-soluble polymer that can act as a graphene dispersion stabilizer to produce a graphene sheet in a polar solvent, for example, an aqueous solution rather than an organic solvent only through a non-thermal treatment and physical method. After that, the re-stacking of the graphene can be prevented, so that the single layer graphene has excellent colloidal dispersion and stability.
또한, 본 발명의 그래핀하이드로겔은 산업전반에 걸쳐 다양하게 적용이 가능하면서도 고안정성 콜로이드 그래핀용액에 포함된 합성수용성고분자를 가교시킴으로써 형성할 수 있어 공정의 단순화 및 저가형 소재 사용으로 인한 비용감소 효과를 누릴 수 있어 환경친화적인 특성을 갖는다. In addition, the graphene hydrogel of the present invention can be formed by cross-linking the synthetic water-soluble polymer contained in the high stability colloidal graphene solution while being applicable to various industries throughout the industry, simplifying the process and reducing the cost due to the use of low-cost materials It can enjoy the effect and has environmentally friendly characteristics.
또한, 본 발명은 그래핀하이드로겔을 동결건조하여 제조된 그래핀에어로겔을 다양하게 산업전반에 적용할 수 있는데, 특히 그래핀 에어로겔을 활용한 흡착제 및 전도성 분리막을 제공할 수 있다.In addition, the present invention can be applied to a variety of industries, such as graphene aerogel prepared by lyophilizing the graphene hydrogel, in particular it can provide an adsorbent and a conductive separator using a graphene aerogel.
도 1a는 본 발명의 일 실시예에 따른 합성수용성고분자인 PH-PVA의 합성 개략도이고, 도 1b는 본 발명의 다른 실시예에 따른 합성수용성고분자인 PH-DT의 합성 개략도이며, 도 1c는 본 발명의 또 다른 실시예에 따른 합성수용성고분자인 Py-PVA의 합성 개략도이고, 도 1d는 본 발명의 또 다른 실시예에 따른 합성수용성고분자인 Py-DT의 합성 개략도이며, 도 1e는 PVA 및 DT에 소수성기인 PH- 및 Py- 작용기를 부착하기 전과 후의 UV 가시광성 흡수 스펙트럼이고, 도 1f는 EPP 및 아미노피렌의 UV 가시광성 흡수 스펙트럼이다.Figure 1a is a synthetic schematic diagram of the synthetic water-soluble polymer PH-PVA according to an embodiment of the present invention, Figure 1b is a synthetic schematic diagram of the PH-DT is a synthetic water-soluble polymer according to another embodiment of the present invention, Figure 1c Synthetic schematic diagram of Py-PVA, a synthetic water-soluble polymer according to another embodiment of the invention, Figure 1d is a synthetic schematic diagram of Py-DT is a synthetic water-soluble polymer, according to another embodiment of the present invention, Figure 1e is PVA and DT UV visible light absorption spectrum before and after attachment of hydrophobic groups, PH- and Py- functional groups, and FIG. 1F is UV visible light absorption spectrum of EPP and aminopyrene.
도 2는 본 발명의 또 다른 실시예에서 합성수용성고분자 농도에 따라 제조된 고안정성 콜로이드 그래핀용액의 상태를 나타낸 사진이다. Figure 2 is a photograph showing the state of the high stability colloidal graphene solution prepared according to the synthetic water-soluble polymer concentration in another embodiment of the present invention.
도 3a 내지 도 3e는 본 발명의 또 다른 실시예에서 5중량%의 합성수용성고분자가 포함된 상태의 고안정성 콜로이드 그래핀용액의 AFM 결과이미지이다.3A to 3E are AFM results of the highly stable colloidal graphene solution containing 5% by weight of synthetic water-soluble polymer in another embodiment of the present invention.
도 4a 내지 도 4e는 본 발명의 또 다른 실시예에서 10중량%의 합성수용성고분자가 포함된 상태의 고안정성 콜로이드 그래핀용액의 AFM 결과이미지이다.4A to 4E are AFM result images of the highly stable colloidal graphene solution containing 10% by weight of synthetic water-soluble polymer in another embodiment of the present invention.
도 5는 본 발명의 또 다른 실시예에서 5중량% PH-PVA로 얻어진 그래핀 편의 라만스펙트럼 결과이미지이다.5 is a Raman spectrum result image of the graphene piece obtained by 5 wt% PH-PVA in another embodiment of the present invention.
도 6a는 본 발명의 고안정성 콜로이드 그래핀용액으로부터 그래핀 하이드로겔 및 그래핀 에어로겔을 제조하는 과정을 나타낸 사진이고, 도 6b 내지 도 6d는 본 발명의 또 다른 실시예에서 얻어진 그래핀 하이드로겔의 기계적 특성에 대한 실험결과 사진들이다.Figure 6a is a photograph showing a process for producing a graphene hydrogel and graphene aerogel from the high stability colloidal graphene solution of the present invention, Figure 6b to 6d is a graphene hydrogel obtained in another embodiment of the present invention The results of the experiment on the mechanical properties are photographs.
도 7a는 서로 다른 농도에서의 메틸렌블루의 UV-가시광선 흡수 스펙트럼들이고, 도 7b는 도 7a의 스펙트럼으로부터 유래된 calibration curve이며, 도 7c는 본 발명의 또 다른 실시예에서 메틸렌블루용액에 본 발명의 그래핀 에어로겔 처리 전후의 색깔변화 및 UV가시광선흡수스펙트럼을 나타낸 사진이다.FIG. 7A shows the UV-visible absorption spectra of methylene blue at different concentrations, FIG. 7B is a calibration curve derived from the spectrum of FIG. 7A, and FIG. 7C shows the present invention in a methylene blue solution in another embodiment of the invention. The photo shows the color change and UV visible absorption spectrum before and after graphene airgel treatment.
도 8은 본 발명의 또 다른 실시예에서 본 발명의 전극용 분리막이 포함된 고체상태 수퍼캐패시터의 0.5 전류 밀도 g-1에서 기록된 전형적인 정전류 충방전 및 장기 사이클링 성능을 기록한 그래프이다.FIG. 8 is a graph showing typical constant current charge / discharge and long term cycling performances recorded at 0.5 current density g −1 of a solid state supercapacitor including the separator for electrodes of the present invention in another embodiment of the present invention.
본 발명에서 사용되는 용어는 본 발명에서의 기능을 고려하면서 가능한 현재 널리 사용되는 일반적인 용어들을 선택하였으나, 이는 당 분야에 종사하는 기술자의 의도 또는 판례, 새로운 기술의 출현 등에 따라 달라질 수 있다. 또한, 특정한 경우는 출원인이 임의로 선정한 용어도 있으며, 이 경우 해당되는 발명의 설명 부분에서 상세히 그 의미를 기재할 것이다. 따라서 본 발명에서 사용되는 용어는 단순한 용어의 명칭이 아닌, 그 용어가 가지는 의미와 본 발명의 전반에 걸친 내용을 토대로 정의되어야 한다.The terms used in the present invention have been selected as widely used general terms as possible in consideration of the functions in the present invention, but this may vary according to the intention or precedent of the person skilled in the art, the emergence of new technologies and the like. In addition, in certain cases, there is also a term arbitrarily selected by the applicant, in which case the meaning will be described in detail in the description of the invention. Therefore, the terms used in the present invention should be defined based on the meanings of the terms and the contents throughout the present invention, rather than the names of the simple terms.
이하, 첨부한 도면 및 바람직한 실시예들을 참조하여 본 발명의 기술적 구성을 상세하게 설명한다.Hereinafter, with reference to the accompanying drawings and preferred embodiments will be described in detail the technical configuration of the present invention.
그러나, 본 발명은 여기서 설명되는 실시예에 한정되지 않고 다른 형태로 구체화 될 수도 있다. 명세서 전체에 걸쳐 본 발명을 설명하기 위해 사용되는 동일한 참조번호는 동일한 구성요소를 나타낸다.However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Like reference numerals used to describe the present invention throughout the specification denote like elements.
본 발명은 그 기술적 특징이 그래파이트에서 분리된 그래핀이 극성용매에서 균일하게 분산된 상태를 유지할 수 있도록 수용성고분자를 백본으로하여 합성된 새로운 구조의 그래핀분산안정제용 합성수용성고분자, 그 합성수용성고분자를 포함함으로써 그래핀의 리스태킹을 방지할 수 있어 그래핀의 콜로이드 분산성 및 안정성이 탁월한 특성을 갖는 고안정성 콜로이드 그래핀용액, 상기 그래핀용액으로 형성된 하이드로겔 및 이를 포함하는 다양한 응용제품에 있으므로 이점을 고려하여 본 발명을 설명한다. The present invention is a synthetic water-soluble polymer for graphene dispersion stabilizer of a novel structure synthesized by using a water-soluble polymer as a backbone so that the graphene separated from the graphite can be uniformly dispersed in a polar solvent, the synthetic water-soluble polymer It is possible to prevent re-tacking of the graphene by including a high stability colloidal graphene solution having excellent colloidal dispersibility and stability of the graphene, since the hydrogel formed from the graphene solution and various applications including the same In view of this, the present invention will be described.
즉, 종래 흑연으로부터 그래핀을 분리하는 방법 특히 삽입물(intercalants)을 이용한 흑연의 박리(exfoliation)는 항상 분리된 그래핀 조각들에 잔류 삽입물이 남는다. 고분자 삽입물의 제거는 매우 작은 분자들의 제거보다는 더 어렵고 합성된 그래핀의 유용성을 저해할 가능성이 높은 문제가 있었다. 하지만 본 발명은 이러한 문제점을 해결하여 합성수용성고분자에 의해 안정화된 그래핀 편의 수성분산액을 얻을 수 있으며, 이러한 수성분산액은 그래핀의 리스택킹을 방지하기 위해 삽입물로 사용된 합성수용성고분자를 제거하지 않고 직접 응용할 수 있는 것에 그 기술적 특징이 있다. 즉, 수성분산액에 포함된 합성수용성고분자를 가교시켜 하이드로겔을 형성하고, 하이드로겔로부터 에어로겔을 만들어서 이를 응용할 수 있기 때문이다.That is, exfoliation of graphite using intercalants, especially methods of separating graphene from conventional graphite, always leaves residual inserts in the separated graphene pieces. The removal of polymer inserts is more difficult than the removal of very small molecules and has a high probability of inhibiting the usefulness of the synthesized graphene. However, the present invention solves these problems to obtain an aqueous acid solution of the graphene fragment stabilized by the synthetic water-soluble polymer, and this aqueous acid solution does not remove the synthetic water-soluble polymer used as an insert to prevent retacking of the graphene. Its technical features are directly applicable. That is, it is because crosslinking the synthetic water-soluble polymer contained in the aqueous acid solution to form a hydrogel, and can be applied by making an aerogel from the hydrogel.
먼저, 본 발명의 그래핀 분산안정제용 합성수용성고분자는 1개 이상의 소수성작용기가 부가된 구조, 친수성작용기 중 1개 이상이 소수성작용기로 치환된 구조 또는 1개 이상의 소수성작용기가 부가되고 친수성작용기 중 1개 이상이 소수성작용기로 치환된 구조를 갖는다. First, the synthetic water-soluble polymer for the graphene dispersion stabilizer of the present invention has a structure in which at least one hydrophobic functional group is added, at least one hydrophilic functional group is substituted with a hydrophobic functional group, or at least one hydrophobic functional group is added to one of the hydrophilic functional groups. Two or more have a structure substituted with a hydrophobic functional group.
이와 같이, 수용성고분자에 1개 이상의 소수성작용기가 도입된 합성수용성고분자는 극성용매 특히 수용액상에서 쉽게 용해될 뿐만 아니라 도입된 소수성작용기를 통해 그래핀과 용이하게 결합할 수 있는 장점을 갖게 된다. 따라서, 본 발명의 합성수용성고분자가 용해된 극성용매 예를 들어 수용액 상태에서 물리적처리에 의해 흑연으로부터 그래핀 시트가 형성되면, 그래핀시트 사이에 합성수용성고분자가 끼어 들어가 그래핀 시트의 π-π 상호작용을 차단하여 그래핀 시트의 리스태킹을 방지할 수 있으므로 그래핀이 균일하게 분산된 고안정성 콜로이드 그래핀 용액을 얻을 수 있다. As such, the synthetic water-soluble polymer having one or more hydrophobic functional groups introduced into the water-soluble polymer has the advantage of being easily dissolved in a polar solvent, especially an aqueous solution, and easily combined with graphene through the introduced hydrophobic functional groups. Therefore, when a graphene sheet is formed from graphite by physical treatment in an aqueous solution state, for example, a polar solvent in which the synthetic water-soluble polymer of the present invention is dissolved, the synthetic water-soluble polymer is sandwiched between the graphene sheets, π-π of the graphene sheet. Since the interaction can be prevented to prevent re-tacking of the graphene sheet, a highly stable colloidal graphene solution in which graphene is uniformly dispersed can be obtained.
여기서, 수용성고분자는 공지된 수용성고분자가 모두 사용될 수 있으나, 폴리비닐알코올[Poly(vinyl alcohol)], 덱스트란(Dextran), 전분(Starch), 폴리에틸렌옥사이드(Polyethylene oxide), 폴리아크릴아마이드(Polyacrylamide), 폴리비닐피롤리돈(Polyvinyl pyrrolidone), 폴리아크릴릭엑시드(Polyacrylic acid), 폴리 스타이렌설포닉엑시드[Poly(styrenesulfonic acid)], 폴리실릭익엑시드[Poly(silicic acid)], 폴리포스포릭엑시드[Poly(phosphoric acid)], 폴리에틸렌설포닉엑시드[Poly(ethylene sulfonic acid)], 폴리말레익엑시드[Poly(maleic acid)], 폴리아마인스(Polyamines), 폴리아크릴아마이드(Poly acrylamide), 폴리비닐피롤리돈(Poly vinyl pyrrolidone), 및 폴리에틸렌글리콜(Poly Ethylene Glycol)로 구성된 그룹에서 선택된 1개 이상일 수 있다.Here, the water-soluble polymer can be used all known water-soluble polymer, polyvinyl alcohol [Poly (vinyl alcohol)], dextran (Dextran), starch (Starch), polyethylene oxide (polyethylene oxide), polyacrylamide (Polyacrylamide) , Polyvinylpyrrolidone, polyacrylic acid, polystyrene sulfonic acid [Poly (styrenesulfonic acid)], polysilic acid [Poly (silicic acid)], polyphosphoric acid [Poly (phosphoric acid)], poly (ethylene sulfonic acid), poly (maleic acid), polyamines, poly acrylamide, polyvinylpyrrolye It may be at least one selected from the group consisting of polyvinyl pyrrolidone, and polyethylene glycol (polyethylene glycol).
또한, 수용성고분자에 도입되는 소수성 작용기는 알콕시기, 플루오레닐기, 카바졸기, 니트릴기, 티오펜기, 벤조티오펜기, 니트로기, 아릴기, 알킬기, 알케닐기, 알콕시기, 플루오레닐기, 비페닐기, 트라이페틸기, 터페닐기, 스틸벤기, 나프틸기, 비나프틸기, 안트라세닐기, 페난트레닐기, 페릴레닐기, 테트라세닐기, 크라이세닐기, 플로오레닐기, 아세나프타세닐기, 트리헤닐렌기, 플로오란텐기, 페닐기, 파이레닐기로 구성된 그룹에서 선택된 1개 이상일 수 있다.In addition, the hydrophobic functional groups introduced into the water-soluble polymer are alkoxy, fluorenyl, carbazole, nitrile, thiophene, benzothiophene, nitro, aryl, alkyl, alkenyl, alkoxy, fluorenyl, Biphenyl group, trifetyl group, terphenyl group, stilbene group, naphthyl group, vinapthyl group, anthracenyl group, phenanthrenyl group, perrylenyl group, tetrasenyl group, chrysenyl group, fluorenyl group, acenaphthacenyl group, tri It may be at least one selected from the group consisting of a heylene group, a fluoroanthene group, a phenyl group, and a pyrenyl group.
특히, 그래핀의 특성을 고려하면 소수성 작용기가 아로마틱 링을 포함하는 구조인 것이 바람직할 수 있을 것이다.In particular, considering the characteristics of the graphene it may be preferable that the hydrophobic functional group is a structure containing an aromatic ring.
다음으로, 본 발명의 고안정성 콜로이드 그래핀용액은 그래핀 분산안정제용 합성수용성고분자에 의해 그래핀이 극성용매에 균일하게 분산된 것으로서, 그래핀 분산안정제용 합성수용성고분자는 0.1중량% 내지 80중량%, 그래핀 0.005 내지 40중량%, 및 나머지 중량의 용매를 포함할 때 가장 안정적으로 고안정성 콜로이드형태를 유지할 수 있음을 실험적으로 확인하였다. Next, the high-stable colloidal graphene solution of the present invention is that the graphene is uniformly dispersed in the polar solvent by the synthetic water-soluble polymer for graphene dispersion stabilizer, the synthetic water-soluble polymer for graphene dispersion stabilizer 0.1% by weight to 80% It was experimentally confirmed that the most stable stably colloidal form can be maintained when it contains%, graphene 0.005 to 40% by weight, and the remaining weight of the solvent.
한편, 본 발명의 고안정성 콜로이드형태의 그래핀 용액은 가용성 전도성 고분자 용액과 그래파이트를 물 또는 유기용매에 첨가한 후 1분 내지 60분 동안 물리적 처리를 수행하게 되면 용이하게 제조할 수 있다. 여기서 물리적 처리는 초음파 처리 또는 볼밀링(ball milling)을 포함할 수 있으며, 그래파이트로부터 단일층 그래핀을 분리할 수 있다. Meanwhile, the highly stable colloidal graphene solution of the present invention can be easily prepared by performing physical treatment for 1 minute to 60 minutes after adding a soluble conductive polymer solution and graphite to water or an organic solvent. The physical treatment may include sonication or ball milling, and may separate single layer graphene from graphite.
다음으로, 본 발명의 고안정성 콜로이드 그래핀용액 제조방법은 상술된 그래핀 분산안정제용 합성수용성고분자를 준비하는 단계 및 준비된 합성수용성고분자와 흑연입자를 극성용매에 첨가한 후 물리적 처리를 수행하는 단계를 포함한다.  Next, the method for preparing a highly stable colloidal graphene solution of the present invention comprises the steps of preparing a synthetic water-soluble polymer for the graphene dispersion stabilizer and adding the prepared synthetic water-soluble polymer and graphite particles to a polar solvent and then performing physical treatment. It includes.
여기서 흑연입자는 그래핀의 원료물질로서 실질적으로 그래핀이 다층적으로 응집되어 있어 두께가 어느 정도 두꺼운 것을 의미하는데, 순수한 흑연 또는 팽창(exfoliated)된 흑연을 포함한다.Here, the graphite particles mean that the graphene is substantially thick as the raw material of graphene, and the thickness of the graphene is agglomerated in multiple layers, and includes pure graphite or expanded graphite.
물리적 처리는 초음파 처리 또는 볼밀링(ball milling) 또는 호모지나이저(homogenizer)를 포함할 수 있으며, 그래파이트와 팽창된 그래파이트로부터 그래핀을 분리할 수 있다. 특히, 물리적 처리는 10초 내지 120분, 바람직하게는 1분 내지 60분, 더욱 바람직하게는 10분 내지 30분 동안 수행될 수 있는데, 이러한 물리적 처리를 통해 간단하면서도 물성에 결함이 없는 그래핀으로 분리될 수 있다.Physical treatment may include sonication or ball milling or homogenizer, and may separate graphene from graphite and expanded graphite. In particular, the physical treatment may be carried out for 10 seconds to 120 minutes, preferably 1 minute to 60 minutes, more preferably 10 minutes to 30 minutes, through the physical treatment to a simple but defect-free graphene Can be separated.
일예로, 합성수용성고분자와 흑연을 물에 첨가한 후 10초 내지 120분 동안 물리적 처리를 수행하게 되면 고안정성 콜로이드 그래핀용액을 용이하게 제조할 수 있게 된다. For example, when the synthetic water-soluble polymer and graphite are added to water and subjected to physical treatment for 10 seconds to 120 minutes, it is possible to easily prepare a highly stable colloidal graphene solution.
이러한 본 발명의 고안정성 콜로이드 그래핀용액 제조방법에 의하면 손상이 최소화된 많은 양의 단일층 그래핀을 용이하게 제조할 수 있다.According to the method for preparing a highly stable colloidal graphene solution of the present invention, it is possible to easily prepare a large amount of single layer graphene with minimal damage.
다음으로, 본 발명의 그래핀 하이드로겔은 고안정성 콜로이드 그래핀 용액에 포함된 합성수용성고분자를 가교반응시켜 형성되는데, 가교반응은 상기 고안정성 콜로이드 그래핀 용액 90 내지 99.9중량% 및 가교제 0.1 내지 10중량%를 포함하여 이루어질 수 있다. 본 발명에서 사용되는 가교제는 수용성고분자를 가교시킬 수 있는 공지된 모든 가교제가 사용될 수 있는데, 후술하는 실시예에서는 황산촉매하에서 Glutaraldehyde가 사용되었다. Next, the graphene hydrogel of the present invention is formed by crosslinking the synthetic water-soluble polymer contained in the high stability colloidal graphene solution, the crosslinking reaction is 90 to 99.9% by weight of the high stability colloidal graphene solution and 0.1 to 10 crosslinking agent It may comprise a weight percent. As a crosslinking agent used in the present invention, any known crosslinking agent capable of crosslinking a water-soluble polymer may be used. In the examples described below, Glutaraldehyde was used under a sulfuric acid catalyst.
다음으로, 본 발명의 그래핀 에어로겔은 그래핀 하이드로겔에 포함된 수분을 제거하여 형성되는데, 수분은 공지된 모든 방법으로 제거될 수 있으나, 특히 그래핀 하이드로겔을 동결건조하여 제거될 수 있다. 이와 같이 형성된 그래핀에어로겔은 흡착제나 전도성분리막 등 다양한 제품에 응용가능하다.Next, the graphene airgel of the present invention is formed by removing the water contained in the graphene hydrogel, the water can be removed by any known method, in particular can be removed by lyophilizing the graphene hydrogel. The graphene airgel formed as described above is applicable to various products such as adsorbents or conductive separators.
실시예 1. Example 1.
그래핀분산안정제용 합성수용성고분자 준비Preparation of synthetic water-soluble polymer for graphene dispersion stabilizer
1. Phenoxy-PVA제조1. Manufacture of Phenoxy-PVA
도 1a에 도시된 바와 같이 수용성고분자인 PVA에 소수성기를 도입하기 위해 EPP(1,2-epoxy??phonoxypropane)를 다음과 같이 반응시켜 Phenoxy-PVA를 제조하였다.As illustrated in FIG. 1A, Phenoxy-PVA was prepared by reacting EPP (1,2-epoxy ?? phonoxypropane) to introduce a hydrophobic group into PVA, which is a water-soluble polymer.
6.0 g의 PVA는 먼저 40 ℃에서 200 ㎖의 1 M NaOH 용액에 용해하고 4.1 g의 EPP를 상기 용액에 첨가하였다. 반응은 24 시간 동안 계속했다. 반응 종료 후, 생성 된 생성물을 과량의 메탄올을 첨가하여 침전시키고, 여과하여 Phenoxy-PVA (PH-PVA)얻었다. 6.0 g of PVA was first dissolved in 200 ml of 1 M NaOH solution at 40 ° C. and 4.1 g of EPP was added to the solution. The reaction continued for 24 hours. After completion of the reaction, the resulting product was precipitated by addition of excess methanol and filtered to give Phenoxy-PVA (PH-PVA).
2.Phenoxy-Dextran 의 제조2.Manufacture of Phenoxy-Dextran
도 1b에 도시된 바와 같이 수용성고분자인 덱스트란(Dextran)에 소수성기를 도입하기 위해 EPP를 다음과 같이 반응시켜 Phenoxy-Dextran(PH-DT)을 제조하였다. PH-DT의 합성 절차는 PH-PVA 유사하다. As shown in FIG. 1B, Phenoxy-Dextran (PH-DT) was prepared by reacting EPP as follows to introduce a hydrophobic group into a water-soluble polymer, Dextran. The synthetic procedure of PH-DT is similar to PH-PVA.
6.0 g의 DT는 24 시간 동안 40℃로 1 M NaOH 용액 200 ㎖에서 11.1 × 10-1g의 EPP와 반응시켰다. 이어서, 반응용액에 과량의 메탄올을 첨가하여 PH-DT를 침전시켰다.6.0 g of DT was reacted with 11.1 × 10 −1 g of EPP in 200 ml of a 1 M NaOH solution at 40 ° C. for 24 hours. Subsequently, excess methanol was added to the reaction solution to precipitate PH-DT.
3. Pyrene-PVA의 제조3. Preparation of Pyrene-PVA
도 1c에 도시된 바와 같이 수용성고분자인 PVA에 소수성기를 도입하기 위해 다음과 같이 반응시켜 Pyrene-PVA(Py-PVA)를 제조하였다. As shown in FIG. 1c, Pyrene-PVA (Py-PVA) was prepared by reacting as follows to introduce a hydrophobic group to PVA, which is a water-soluble polymer.
먼저, 6.0 g의 PVA을 100㎖의 NMP에 용해하고 24 시간 동안 60 ℃에서 8.3 × 10-1g DMAP의 존재 하에서 6.9 × 10-1g 숙신산 무수물과 에스테르화 반응을 통해 카복실레이트화 시켰다. 이소프로필 알코올 용액을 사용하여 생성물인 카복실레이트된 PVA를 상기 용액 내에서 침전시켰다. 생성물은 후속 반복 여과 과정을 통해 정제하고, 25℃로 진공에서 건조시켰다. 피레닐 기의 부착을 위해, 얻어진 카르복실레이트 된 PVA 6.5g과 12.5 × 10-1g의 아미노 피렌, 1.6 g의 DMTMM 및 0.2 ㎖의 DIPEA를 24 시간 동안 25 ℃로 증류수에서 반응시켰다. 최종생성물인 Py-PVA는 과량의 이소프로필 알코올을 사용하여 얻었다.First, 6.0 g of PVA was dissolved in 100 ml of NMP and carboxylated by esterification with 6.9 × 10 −1 g succinic anhydride in the presence of 8.3 × 10 −1 g DMAP at 60 ° C. for 24 hours. The product, carboxylated PVA, was precipitated in the solution using an isopropyl alcohol solution. The product was purified through subsequent repeated filtration and dried in vacuo to 25 ° C. For the attachment of the pyrenyl group, 6.5 g of the carboxylated PVA and 12.5 × 10 −1 g of aminopyrene, 1.6 g of DMTMM and 0.2 ml of DIPEA were reacted in distilled water at 25 ° C. for 24 hours. The final product, Py-PVA, was obtained using excess isopropyl alcohol.
4. Pyrene-Dextran의 제조4. Manufacture of Pyrene-Dextran
도 1d에 도시된 바와 같이 수용성고분자인 Dextran에 소수성기를 도입하기 위해 다음과 같이 반응시켜 Pyrene-Dextran(Py-DT)을 제조하였다. As shown in FIG. 1d, Pyrene-Dextran (Py-DT) was prepared by reacting as follows to introduce a hydrophobic group to Dextran, which is a water-soluble polymer.
DT 6.0 g과 18.5 × 10-2g 숙신산 무수물 및 22.6 × 10-2g DMAP를 60℃로 24 시간 동안 100 mL의 NMP에서 반응시켰다. 그 후 얻어진 카르복실레이트된 DT를 침전시키고 여과를 통해 수거하여 진공에서 건조시킨 후, 과량의 이소프로필 알콜로 세척하였다. 피렌을 카복실레이트된 DT(0.4 g)에 100 ㎖의 증류수에서 DMTMM (0.5 g) 및 DIPEA (3.2 × 10-1g)을 채택한 상태로 같은 커플링 화학을 사용하여 공유결합하도록 부착시켰다. 이소프로필알콜이 최종제품 DT-Py를 얻기 위해 사용되었다.6.0 g of DT, 18.5 × 10 −2 g succinic anhydride and 22.6 × 10 −2 g DMAP were reacted at 60 ° C. in 100 mL of NMP for 24 hours. The carboxylated DT obtained was then precipitated, collected via filtration, dried in vacuo and washed with excess isopropyl alcohol. Pyrene was attached to carboxylated DT (0.4 g) covalently using the same coupling chemistry with DMTMM (0.5 g) and DIPEA (3.2 × 10 −1 g) in 100 ml of distilled water. Isopropyl alcohol was used to obtain the final product DT-Py.
실험예 1Experimental Example 1
실시예1에서 얻어진 합성수용성고분자 PH-PVA, PH-DT, Py-PVA, Py-DT에 대해 소수성기가 도입되었는지 여부를 확인하기 위해 UVvisible spectroscopy를 실험하고 그 결과를 도 1e에 나타내었다.UVvisible spectroscopy was performed to confirm whether hydrophobic groups were introduced to the synthetic water-soluble polymers PH-PVA, PH-DT, Py-PVA, and Py-DT obtained in Example 1, and the results are shown in FIG. 1E.
도 1e에 도시된 바와 같이, 수용성고분자에 페닐 및 피레닐 작용기가 도입되었음을 확인할 수 있다. 특히, 도 1f에 도시된 EPP 및 아미노피렌의 자외선-가시 광선스펙트럼과 비교하면 이를 명확하게 알 수 있다. PH-PVA 및 PH-DT의 스펙트럼에서 페닐기의 흡수 피크는 200 ~ 300 nm의 적색 시프팅이 나타났다. 아미노 피렌의 흡수 피크는 대략 300-400nm에서 발생했다. 아미노피렌의 용해도가 매우 낮으므로, 물에서 고강도 흡수 스펙트럼을 얻을 수 없다. 그러나, 수용성 중합체인 PVA 및 DT에 피렌의 부착이 물에 용해되게 만들 것이다. 그 결과, Py-PVA 및 Py-DT의 스펙트럼에서 300 ~ 600 nm에서 강한 흡수 밴드가 관찰되는 것을 알 수 있다. As shown in Figure 1e, it can be seen that the phenyl and pyrenyl functional groups are introduced into the water-soluble polymer. In particular, this can be clearly seen when compared with the ultraviolet-visible light spectrum of EPP and aminopyrene shown in FIG. 1F. The absorption peak of the phenyl group in the spectra of PH-PVA and PH-DT showed red shifting of 200-300 nm. The absorption peak of aminopyrene occurred at approximately 300-400 nm. Since the solubility of aminopyrene is very low, high intensity absorption spectra cannot be obtained in water. However, the attachment of pyrene to water-soluble polymers PVA and DT will cause it to dissolve in water. As a result, it can be seen that a strong absorption band is observed at 300 to 600 nm in the spectra of Py-PVA and Py-DT.
실시예 2Example 2
고안정성 콜로이드 그래핀 용액 준비Highly stable colloidal graphene solution preparation
실시예 1에서 얻어진 PH-PVA, Py-PVA, Py-DT를 각각 증류수 5 mL에 5중량% 및 10중량% 농도로 첨가한 후 용해시켰다. 완전 용해가 된 이후에 0.0009g의 exfoliated graphite(시그마 - 알드리치)를 넣고 ultrasonic을 이용하여 60 %의 진폭에서 30분 동안 분산시켰다. 그 후 최종 검은 용액은 불안정한 그래핀 또는 잔류 흑연을 포함하여 별도의 불순물을 분리하기 위하여 10 분 동안 1,000 rpm으로 원심 분리되었다. PH-PVA, Py-PVA, and Py-DT obtained in Example 1 were added to 5 mL of distilled water at 5% by weight and 10% by weight, respectively, and then dissolved. After complete dissolution, 0.0009 g of exfoliated graphite (Sigma-Aldrich) was added and dispersed for 30 minutes at 60% amplitude using ultrasonic wave. The final black solution was then centrifuged at 1,000 rpm for 10 minutes to separate extra impurities, including unstable graphene or residual graphite.
실험예 2Experimental Example 2
실시예 2에서 얻어진 PH-PVA 및 Py-PVA를 포함하는 4개의 고안정성 콜로이드 그래핀 용액을 관찰하고 그 결과사진을 도 2에 나타내었다. 도 2에서, (a)는 합성수용성분자가 5중량% 첨가된 것이고, (b)는 합성수용성고분자가 10중량% 첨가된 것이다. Four highly stable colloidal graphene solutions including PH-PVA and Py-PVA obtained in Example 2 were observed and the photographs are shown in FIG. 2. In Figure 2, (a) is 5% by weight of the synthetic water-containing component, (b) is 10% by weight of the synthetic water-soluble polymer.
도 2로부터, 수용액에서 합성수용성고분자와 흑연의 초음파처리만으로 원심분리후에도 균일하게 불투명한 검은 분산액이 제조되었음을 알 수 있다. From Figure 2, it can be seen that a uniformly opaque black dispersion was prepared even after centrifugation only by ultrasonication of synthetic water-soluble polymer and graphite in an aqueous solution.
실험예 3Experimental Example 3
원자력 현미경(AFM)을 사용하여 실시예2에서 얻어진 6개의 고안정성 콜로이드 그래핀 용액에서 수용액에 분산된 그래핀 편의 특성을 관찰하고 그 결과이미지를 5중량%는 도 3a 내지 도 3e에, 10중량%는 도 4a 내지 도 4e에 나타내었다. 이 때, 도 3a 및 도 4a는 PVA, 3b 및 4b는 PH-PVA, 3c 및 4c는 Py-PVA, 3d 및 4d는DT, 3e 및 4e는 Py-DT의 결과이미지이다. In the six high-stable colloidal graphene solutions obtained in Example 2 using atomic force microscopy (AFM), the characteristics of the graphene pieces dispersed in the aqueous solution were observed. As a result, 5% by weight of the image was shown in FIGS. 3A to 3E and 10% by weight. % Is shown in FIGS. 4A-4E. 3A and 4A are PVA, 3b and 4b are PH-PVA, 3c and 4c are Py-PVA, 3d and 4d are DT, and 3e and 4e are Py-DT.
예상과 같이, 더 불투명한 검은 용액은 서로 다른 크기와 두께의 많은 그래 핀 조각이 포함되어 있다. 그래핀 시트의 적층 수와 크기는 합성수용성고분자의 화학 구조 및 농도에 의존하는 것으로 판단된다. 또한, 같은 농도의 자연 그대로의 PVA는 자연 그대로의 DT보다 큰 크기의 더 나은 분산 그래 핀 조각을 얻을 수 있음을 관찰할 수 있었다. 특히, 합성수용성고분자의 농도가 증가한 10 중량%에서, 그래핀 편이 모두 얇고 커져 보이는 것을 관찰할 수 있다.As expected, the more opaque black solution contains many graphene fragments of different sizes and thicknesses. The lamination number and size of the graphene sheet is determined to depend on the chemical structure and concentration of the synthetic water-soluble polymer. It was also observed that native PVA at the same concentration yielded better dispersed graphene pieces of larger size than native DT. In particular, at 10% by weight, the concentration of the synthetic water-soluble polymer, it can be observed that all the graphene pieces appear thin and large.
실험예 4Experimental Example 4
그래핀 편의 품질에 대한 정보를 더 관찰하기 위해 실시예 2에서 준비된 5중량% PH-PVA에 포함된 그래핀 층의 적층수를 라만 스펙트라로 관찰하고, 그 결과는 도 5에 도시하였다.In order to further observe the information on the quality of the graphene piece, the lamination spectra of the graphene layer included in the 5 wt% PH-PVA prepared in Example 2 were observed by Raman spectra, and the results are shown in FIG. 5.
대표적인 스펙트럼은 도 5의 (a)에 도시되어 있다. 작은 D 피크는 이중층의 스펙트럼에서 관찰된다. 그러나, D 피크는 적층수가 증가함에 따라 점점 감소되고, 6 내지 10 층 편의 스펙트럼에서 완전히 사라진다. 이것은 비-SP2 공유 작용 및 결함을 측정하는 D 피크에 그래핀 가장자리가 기여할 가능성 때문이다. Representative spectra are shown in FIG. Small D peaks are observed in the spectrum of the bilayer. However, the D peak gradually decreases as the number of stacked layers increases, and disappears completely in the spectrum of 6 to 10 layer pieces. This is due to the possibility of graphene edge contribution to the D peak, which measures non-SP 2 covalent action and defects.
도 5의 (b)에 도시 된 바와 같이, 2D 피크는 그래핀 층의 적층수에 따라 변화한다. 2D 피크의 모양에서 변화는 박편에서 그래핀 층수가 AB 배열로 적층되어 있음을 확인해 준다. 따라서, 본 발명의 실험 조건에서, 사용된 합성수용성고분자가 효율적으로 흑연을 심각하게 SP2 탄소 결합 네트워크를 저하시키지 않고 그래핀 조각으로 절단 할 수 있고, 산화그래핀을 환원시키는 방법과는 대조적으로, 수용액에서 그들을 안정화할 수 있다는 것을 알 수 있었다. As shown in FIG. 5B, the 2D peak changes according to the number of stacked layers of graphene. The change in shape of the 2D peak confirms the stacking of graphene layers in the AB array in the flakes. Thus, under the experimental conditions of the present invention, the synthetic water-soluble polymers used can efficiently cut graphite into pieces of graphene without seriously degrading the SP 2 carbon bonding network, as opposed to the method of reducing graphene oxide. It was found that they can be stabilized in aqueous solution.
실시예 3Example 3
그래핀 하이드로겔 준비Graphene Hydrogel Preparation
실시예 1에서 얻어진 Py-PVA 0.56 g을 증류수 5 mL에 첨가한 후 용해시켰다. 완전 용해가 된 이후에 0.0009g의 exfoliated graphite를 넣고 ultrasonic을 이용하여 30분 동안 분산 시켜 고안정성 콜로이드 그래핀 용액을 얻었다. 그 후 상기 고안정성 콜로이드 그래핀 용액 5ml에 가교제로서 Glutaraldehyde 1 wt%(0.011 mL)를 첨가하고 직후에 촉매로서 0.08 M H2SO4(2.4 mL)를 첨가하여 잘 교반시켰다. 교반 후 즉시 주형에 부어 넣고 상온에서(80°C 이내의 온도 범위) 12시간 동안 가교 반응을 지속시켰다. pH가 일정하게 될 때까지 겔화 후, 하이드로 겔을 과량의 증류수로 세정 하여 황산 같은 잔여물질 등을 제거한 후 도 6a에 도시된 사진과 같은 하이드로겔을 얻었다. 0.56 g of Py-PVA obtained in Example 1 was added to 5 mL of distilled water and then dissolved. After complete dissolution, 0.0009 g of exfoliated graphite was added and dispersed for 30 minutes using ultrasonic to obtain a highly stable colloidal graphene solution. Thereafter, 1 wt% (0.011 mL) of Glutaraldehyde as a crosslinking agent was added to 5 ml of the highly stable colloidal graphene solution, and immediately after stirring, 0.08 MH 2 SO 4 (2.4 mL) was added as a catalyst. Immediately after stirring, the mixture was poured into a mold and the crosslinking reaction was continued for 12 hours at room temperature (temperature range within 80 ° C). After gelation until the pH becomes constant, the hydrogel was washed with excess distilled water to remove residual substances such as sulfuric acid, and the hydrogel as shown in FIG. 6a was obtained.
실험예 5Experimental Example 5
실시예 3에서 얻어진 그래핀 하이드로겔의 물리적 특성을 기계적 강도, 물을 매개로 한 수축-팽창정도 및 SEM으로 각각 조사하고 그 결과를 도 6b 내지 도 6d에 나타내었다.Physical properties of the graphene hydrogel obtained in Example 3 were investigated by mechanical strength, water-shrinkage-expansion degree, and SEM, respectively, and the results are shown in FIGS. 6B to 6D.
그래핀 하이드로겔은 용액에 분산된 합성수용성고분자인 Py-PVA의 가교 결합에 의한 중합체 사슬 네트워크 내부에 그래핀 편이 삽입된 형태로서 주형에서 분리되더라도 주형에 의해 몰드된 상태를 유지할 수 있는 기꼐적 특성을 가지고 있었다.Graphene hydrogel is a form in which graphene fragments are inserted into a polymer chain network by cross-linking of Py-PVA, a synthetic water-soluble polymer dispersed in a solution. Had
도 6b의 사진은 그래핀 하이드로겔이 양호한 기계적 강도를 갖는 것을 보여주는데, 특히, 높이의 50% 보다 더 압축한 후에도 어떤 구조적 피로 없이 압축하기 전 원형으로 회복되는 것을 알 수 있다. The photo of Figure 6b shows that the graphene hydrogel has good mechanical strength, in particular, it can be seen that after compressing more than 50% of the height, it recovers in a circular form before compression without any structural fatigue.
도 6c의 사진은 물을 매개로 할 때 그래핀 하이드로겔의 팽창된 상태 및 수축된 상태를 보여주는데, 그래핀 하이드로겔은 물의 흡수에 의해 상당히 큰 부피변화가 가능함을 알 수 있다. The photo of Figure 6c shows the expanded state and the contracted state of the graphene hydrogel when water-based, it can be seen that the graphene hydrogel can be significantly changed in volume by the absorption of water.
또한, 도 6d에 도시된 SEM 이미지는 하이드로 겔에 형성된 가시적 구멍을 보여준다. 하이드로겔의 가교 밀도(NC-1)는 0.08이었다.In addition, the SEM image shown in FIG. 6D shows visible holes formed in the hydrogel. The crosslink density (NC- 1 ) of the hydrogel was 0.08.
실시예 4Example 4
그래핀 에어로겔 준비Graphene Airgel Preparation
실시예 3에서 얻어진 하이드로겔을 FTS Dura-Stop/Dura-Top freeze dryer (Kinetics, FTS)로 24 시간 동안 -45 ℃로 진공에서 처리하는 동결 건조을 통해 하이드로겔의 수분을 완전히 제거한 후 에어로겔을 얻었다. The hydrogel obtained in Example 3 was subjected to lyophilization which was treated with FTS Dura-Stop / Dura-Top freeze dryer (Kinetics, FTS) for 24 hours in vacuo at -45 ° C. to completely remove the moisture of the hydrogel, thereby obtaining an airgel.
실험예 6Experimental Example 6
실시예 4에서 얻어진 그래핀 에어로겔이 가진 다공성, 높은 표면적 및 화학적 분자간 상호작용으로 인해 염료 오염물질제거제로서 작용할 수 있는지 알아보기 위해, 그래핀 에어로겔 0.45 g을 10 ㎖의 1 mM의 메틸렌 블루 용액에 첨가 하였다. 그 후 그래핀 에어로겔이 첨가된 메틸렌블루용액을 실온에서 2 시간 동안 자력을 이용하여 교반 하였다. 메틸렌 블루의 농도는 용액 '665 nm의 피크 강도로부터 산출 하고 그 결과를 도 7c에 나타내었다.To determine if the graphene aerogel obtained in Example 4 could act as a dye decontaminant due to its porosity, high surface area and chemical intermolecular interactions, 0.45 g of graphene aerogel was added to 10 ml of 1 mM methylene blue solution. It was. Thereafter, the methylene blue solution to which the graphene airgel was added was stirred using a magnetic force at room temperature for 2 hours. The concentration of methylene blue was calculated from the peak intensity of solution '665 nm and the results are shown in Figure 7c.
도 7a는 서로 다른 농도에서의 메틸렌블루의 UV-가시광선 흡수 스펙트럼들이고, 도 7b는 도 7a의 스펙트럼으로부터 유래된 calibration curve이다.FIG. 7A is the UV-visible absorption spectra of methylene blue at different concentrations, and FIG. 7B is a calibration curve derived from the spectrum of FIG. 7A.
도 7c에 도시된 바와 같이 메틸렌블루 용액의 청색(665 nm에서 메틸렌 블루의 흡착)은 그래핀 에어로겔을 처리한 후 사라졌다. 헤테로 방향족 화합물인 메틸렌 블루는 높은 화학적 친화력에 의해 자발적으로 그래핀 에어로겔에 포함된 그래핀 조각에 흡착되는 것으로 예측된다. 따라서, 본 발명의 그래핀 에어로겔은 수용액 상에 존재하는 염료에 대해 거의 100%의 유효 제거효율을 보여주는 것을 알 수 있다. As shown in FIG. 7C, the blue color of the methylene blue solution (adsorption of methylene blue at 665 nm) disappeared after treatment with graphene aerogels. Methylene blue, a heteroaromatic compound, is expected to adsorb on the graphene fragments contained in graphene airgel spontaneously by high chemical affinity. Therefore, it can be seen that the graphene airgel of the present invention shows an effective removal efficiency of almost 100% with respect to the dye present in the aqueous solution.
실시예 5Example 5
전극용 분리막 준비Separator Preparation for Electrode
실시예 4에서 준비된 에어로겔을 1시간 동안 1 M H2SO4 electrolyte에 침지하여 전극용 분리막을 준비하였다. 즉, 본 발명의 그래핀 에어로겔은 기계적으로 강한 특성을 가지므로 산성 전해질 (H2SO4)을 겔에 함유시켜 전극용 분리막을 제조할 수 있다. The airgel prepared in Example 4 was immersed in 1 MH 2 SO 4 electrolyte for 1 hour to prepare a membrane for the electrode. That is, since the graphene airgel of the present invention has a strong mechanical property, it is possible to prepare an electrode separator by containing an acidic electrolyte (H 2 SO 4 ) in the gel.
실험예 7Experimental Example 7
2 개의 탄소 나노 섬유 (CNF) 전극은 동일한 크기 (8mm×15mm)로 제조 하였다. 실시예 5에서 얻어진 전극용 분리막을 CNF 전극재료 사이에 조립하여 고체 수퍼커패시터를 다음과 같이 제조하였다. 두 개의 스테인레스 스틸 호일(두께 0.001 in)은 집전체로서 이용되었고, 최종적으로 수퍼커패시터는 폴리프로필렌 필름으로 감싸졌다. PVA-only/ H2SO4 겔 전해질이 대조군으로 사용되었다. 이들을 대상으로 정전류 충방전 실험을 수행하고 그 결과를 도 8에 도시하였다. 정전류 충전/방전 곡선은 0.5 g-1의 전류 밀도를 얻었다.Two carbon nanofiber (CNF) electrodes were made of the same size (8mm × 15mm). The separator for electrodes obtained in Example 5 was assembled between CNF electrode materials to prepare a solid supercapacitor as follows. Two stainless steel foils (0.001 in thick) were used as the current collector and finally the supercapacitor was wrapped in a polypropylene film. PVA-only / H 2 SO 4 gel electrolyte was used as a control. Constant current charge / discharge experiments were performed on these, and the results are shown in FIG. 8. The constant current charge / discharge curves yielded a current density of 0.5 g −1 .
도 8에 도시된 바와 같이, 대조군인 PVA-only/겔 전해질(84.2±5.2 Fg- 1)과 비교하여 본 발명의 전극용분리막의 사용(107.5 ± 3.1 Fg- 1)은 보다 높은 용량 및 10,000 사이클 이상의 우수한 장기 사이클 안정성을 허용하는 것을 알 수 있다. 이러한 결과는 본 발명의 전극용 분리막에 포함된 그래핀이 겔의 이온 전도도를 향상시키기 때문인 것으로 예측된다. 8, the control group in PVA-only / gel electrolyte (84.2 ± 5.2 Fg - 1) use of a separator for an electrode of the present invention as compared to (107.5 ± 3.1 Fg - 1) has a higher capacity, and 10,000 cycles It can be seen that the above excellent long-term cycle stability is allowed. This result is expected to be due to the graphene included in the electrode separator of the present invention improves the ionic conductivity of the gel.
이러한 실험결과들은 본 발명에서 제조된 합성수용성고분자를 이용하여 고안정성 콜로이드 그래핀용액을 쉽게 제조할 수 있으며, 그래핀용액에 가교제를 첨가하여 제조된 하이드로 겔 및 이를 동결 건조하여 제조된 에어로겔의 다양한 활용성을 보여준다. 특히 하이드로겔 및 에어로겔의 주요 특성은 삽입되는 그래핀의 함량, 중합체 매트릭스의 다양성 및 겔의 가교 밀도에 의해 제어 될 수 있음을 보여준다. These experimental results can be easily prepared high stability colloidal graphene solution using the synthetic water-soluble polymer prepared in the present invention, a variety of hydrogel prepared by adding a crosslinking agent to the graphene solution and aerogel prepared by freeze drying it Demonstrate usability. In particular, the main properties of hydrogels and aerogels show that they can be controlled by the amount of graphene inserted, the diversity of the polymer matrix and the crosslinking density of the gel.
이상에서 본 발명의 실시예에 대하여 상세하게 설명하였지만 본 발명의 권리범위는 이에 한정되는 것은 아니고 다음의 청구범위에서 정의하고 있는 본 발명의 기본 개념을 이용한 당업자의 여러 변형 및 개량 형태 또한 본 발명의 권리범위에 속한다.Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (17)

1개 이상의 소수성작용기가 부가된 구조, 친수성작용기 중 1개 이상이 소수성작용기로 치환된 구조 또는 1개 이상의 소수성작용기가 부가되고 친수성작용기 중 1개 이상이 소수성작용기로 치환된 구조를 갖는 그래핀 분산안정제용 합성수용성고분자. Graphene dispersion having a structure in which at least one hydrophobic functional group is added, at least one hydrophilic functional group is substituted with a hydrophobic functional group, or at least one hydrophobic functional group is added, and at least one hydrophilic functional group is substituted with a hydrophobic functional group. Synthetic water-soluble polymer for stabilizers.
제 1 항에 있어서, The method of claim 1,
상기 수용성고분자는 폴리비닐알코올[Poly(vinyl alcohol)], 덱스트란(Dextran), 전분(Starch), 폴리에틸렌옥사이드(Polyethylene oxide), 폴리아크릴아마이드(Polyacrylamide), 폴리비닐피롤리돈(Polyvinyl pyrrolidone), 폴리아크릴릭엑시드(Polyacrylic acid), 폴리 스타이렌설포닉엑시드[Poly(styrenesulfonic acid)], 폴리실릭익엑시드[Poly(silicic acid)], 폴리포스포릭엑시드[Poly(phosphoric acid)], 폴리에틸렌설포닉엑시드[Poly(ethylene sulfonic acid)], 폴리말레익엑시드[Poly(maleic acid)], 폴리아마인스(Polyamines), 폴리아크릴아마이드(Poly acrylamide), 폴리비닐피롤리돈(Poly vinyl pyrrolidone), 및 폴리에틸렌글리콜(Poly Ethylene Glycol)로 구성된 그룹에서 선택된 1개 이상인 것을 특징으로 하는 그래핀 분산안정제용 합성수용성고분자. The water-soluble polymer is polyvinyl alcohol [Poly (vinyl alcohol)], dextran (Dextran), starch (Starch), polyethylene oxide (Polyethylene oxide), polyacrylamide, polyvinylpyrrolidone (Polyvinyl pyrrolidone), Polyacrylic acid (Polycrylic acid), polystyrene sulfonic acid (Poly (styrenesulfonic acid)], polysilic acid (Poly (silicic acid)], polyphosphoric acid (Poly (phosphoric acid)], polyethylene sulfonic acid [ Poly (ethylene sulfonic acid)], polymaleic acid], polyamines, poly acrylamide, poly vinyl pyrrolidone, and polyethylene glycol Poly Ethylene Glycol) synthetic water-soluble polymer for graphene dispersion stabilizer, characterized in that at least one selected from the group consisting of.
제 1 항에 있어서, The method of claim 1,
상기 소수성 작용기는 알콕시기, 플루오레닐기, 카바졸기, 니트릴기, 티오펜기, 벤조티오펜기, 니트로기, 아릴기, 알킬기, 알케닐기, 알콕시기, 플루오레닐기, 비페닐기, 트라이페틸기, 터페닐기, 스틸벤기, 나프틸기, 비나프틸기, 안트라세닐기, 페난트레닐기, 페릴레닐기, 테트라세닐기, 크라이세닐기, 플로오레닐기, 아세나프타세닐기, 트리헤닐렌기, 플로오란텐기, 페닐기, 파이레닐기로 구성된 그룹에서 선택된 1개 이상인 것을 특징으로 하는 그래핀 분산안정제용 합성수용성고분자. The hydrophobic functional group is an alkoxy group, fluorenyl group, carbazole group, nitrile group, thiophene group, benzothiophene group, nitro group, aryl group, alkyl group, alkenyl group, alkoxy group, fluorenyl group, biphenyl group, tripetyl group , Terphenyl group, stilbene group, naphthyl group, vinaphthyl group, anthracenyl group, phenanthrenyl group, perylenyl group, tetrasenyl group, chrysenyl group, fluorenyl group, acenaphthacenyl group, trihenylene group, fluoroanthene group Synthetic water-soluble polymer for graphene dispersion stabilizer, characterized in that at least one selected from the group consisting of, phenyl group, pyrenyl group.
제 1 항에 있어서, The method of claim 1,
상기 소수성 작용기는 아로마틱 링을 포함하는 구조인 것을 특징으로 하는 그래핀 분산안정제용 합성수용성고분자. The hydrophobic functional group is a synthetic water-soluble polymer for graphene dispersion stabilizer, characterized in that the structure containing an aromatic ring.
제 1 항 내지 제 4 항 중 어느 한 항의 그래핀 분산안정제용 합성수용성고분자에 의해 그래핀이 극성용매에 균일하게 분산된 것을 특징으로 하는 고안정성 콜로이드 그래핀 용액. The highly stable colloidal graphene solution, characterized in that the graphene is uniformly dispersed in a polar solvent by the synthetic water-soluble polymer of any one of claims 1 to 4.
제 5 항에 있어서, The method of claim 5,
상기 그래핀 분산안정제용 합성수용성고분자는 0.1중량% 내지 80중량%로 포함되는 것을 특징으로 하는 고안정성 콜로이드 그래핀 용액. Highly stable colloidal graphene solution, characterized in that the synthetic water-soluble polymer for the graphene dispersion stabilizer is contained in 0.1% by weight to 80% by weight.
제 5 항에 있어서,The method of claim 5,
상기 극성용매는 물인 것을 특징으로 하는 고안정성 콜로이드 그래핀 용액. The polar solvent is a high stability colloidal graphene solution, characterized in that the water.
제 1 항 내지 제 4 항 중 어느 한 항의 그래핀 분산안정제용 합성수용성고분자를 준비하는 단계; 및Preparing synthetic water-soluble polymer for graphene dispersion stabilizer of any one of claims 1 to 4; And
상기 준비된 합성수용성고분자와 흑연입자를 극성용매에 첨가한 후 물리적 처리를 수행하는 단계;를 포함하는 고안정성 콜로이드 그래핀용액 제조방법. And adding physically prepared synthetic water-soluble polymer and graphite particles to the polar solvent and then performing physical treatment.
제 8 항에 있어서,The method of claim 8,
상기 물리적 처리는 초음파, 볼밀링, 호모지나이저 중 어느 하나로 10초 내지 120분 동안 이루어지는 것을 특징으로 하는 고안정성 콜로이드 그래핀용액 제조방법. The physical treatment is a method for producing a highly stable colloidal graphene solution, characterized in that made for 10 seconds to 120 minutes with any one of ultrasonic, ball milling, homogenizer.
제 5 항의 고안정성 콜로이드 그래핀 용액에 포함된 합성수용성고분자를 가교반응시켜 형성된 그래핀 하이드로겔. A graphene hydrogel formed by crosslinking a synthetic water-soluble polymer contained in the highly stable colloidal graphene solution of claim 5.
제 10 항에 있어서,The method of claim 10,
상기 가교반응은 상기 고안정성 콜로이드 그래핀 용액 90 내지 99.9중량% 및 가교제 0.1 내지 10중량%를 포함하여 이루어지는 것을 특징으로 하는 그래핀 하이드로겔. The crosslinking reaction is graphene hydrogel, characterized in that comprising 90 to 99.9% by weight of the highly stable colloidal graphene solution and 0.1 to 10% by weight of the crosslinking agent.
제 1 항 내지 제 4 항 중 어느 한 항의 그래핀 분산안정제용 합성수용성고분자를 준비하는 단계; Preparing synthetic water-soluble polymer for graphene dispersion stabilizer of any one of claims 1 to 4;
상기 준비된 합성수용성고분자와 흑연입자를 극성용매에 첨가한 후 물리적 처리를 수행하여 고안정성 콜로이드 그래핀용액을 준비하는 단계; 및Preparing a highly stable colloidal graphene solution by adding the prepared synthetic water-soluble polymer and graphite particles to a polar solvent and then performing physical treatment; And
상기 준비된 그래핀용액에 가교제를 첨가하여 상기 합성수용성고분자를 가교반응시켜 가교반응물을 형성하는 단계;를 포함하는 그래핀 하이드로겔 제조방법. Graphene hydrogel manufacturing method comprising the step of cross-linking the synthetic water-soluble polymer to form a crosslinking reactant by adding a crosslinking agent to the prepared graphene solution.
제 12 항에 있어서,The method of claim 12,
상기 가교반응물을 형성한 후 가교반응시 사용된 촉매를 포함한 잔여물질을 제거하는 단계를 더 포함하는 것을 특징으로 하는 그래핀 하이드로겔 제조방법. Forming the cross-linking reactant and removing the remaining material including the catalyst used during the cross-linking reaction graphene hydrogel manufacturing method characterized in that it further comprises.
제 10 항의 그래핀 하이드로겔에 포함된 수분을 제거하여 형성된 그래핀 에어로겔. Graphene airgel formed by removing the water contained in the graphene hydrogel of claim 10.
제 14 항에 있어서,The method of claim 14,
상기 수분은 상기 그래핀 하이드로겔을 동결건조하여 제거되는 것을 특징으로 하는 그래핀 에어로겔. The moisture is graphene airgel, characterized in that the graphene hydrogel is removed by lyophilization.
제 14 항의 그래핀 에어로겔에 전해질을 흡수시켜 형성된 전극용 분리막.Separation membrane for electrodes formed by absorbing the electrolyte in the graphene airgel of claim 14.
제 14 항의 그래핀 에어로겔을 포함하는 흡착제. An adsorbent comprising the graphene airgel of claim 14.
PCT/KR2016/005519 2015-05-29 2016-05-25 Synthetic water-soluble polymer for dispersion stabilizer of graphene, highly stable colloidal graphene solution comprising same polymer, and graphene hydrogel and graphene aerogel comprising same graphene solution WO2016195311A2 (en)

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