CN1312038C

CN1312038C - Large aperture capacity silicon oxide vesicle, foamed material and process for preparing the same

Info

Publication number: CN1312038C
Application number: CNB2005100268374A
Authority: CN
Inventors: 余承忠; 王红宁; 王韵华; 赵东元
Original assignee: Fudan University
Current assignee: Fudan University
Priority date: 2005-06-16
Filing date: 2005-06-16
Publication date: 2007-04-25
Anticipated expiration: 2025-06-16
Also published as: CN1730392A

Abstract

The present invention belongs to the technical field of mesoporous molecular sieve material, particularly to a novel nanometer porous material with large pore volume (as large as 3cm<3>/g), controllable patterns (vesicles, foam, etc.) and adjustable pore size (10 to 200 nm), which is synthesized under mild condition in the method of sol-gel. The preparation method comprises the steps of the preparation of the vesicles and the foam, hydrothermal reaction, drying, the removal of a template agent, etc. The invention has the advantages that the reaction condition is mild, the operation is simple, cosurfactant and cosolvent do not need to be added, and the final material has low cost and is easy to obtain. By changing conditions, such as the ratio of raw materials, the reaction temperature, the pH value of solution and the ion concentration of buffer solution, etc., the physicochemical properties of the porous material, such as the pattern, the pore size and the pore volume, etc., can be changed. The nanometer porous material with large pore volume has wide application foreground in the fields of adsorption, catalyst carriers, drug delivery, separation, chromatography, paint, microreactors, etc.

Description

Large aperture capacity silicon oxide vesicle or foam materials and preparation method thereof

Technical field

The invention belongs to the meso-porous molecular sieve material technical field, be specifically related to a kind of vesica or foam and synthetic method thereof of large aperture capacity silicon oxide.

Background technology

Novel mesopore molecular sieve MCM-41 from 1992 by U.S. Mobil oil company synthetic first since, caused the very big concern of zeolite and catalysis circle, but its pore volume, aperture are less relatively.Stucky[Patrick Schmidt-Winkel, Galen D.Stucky ^*, et al.Chem.Mater.2000,12,686-696] and the mesoporous vesica (MCF) for preparing of co-workers, have than large pore volume and aperture, make organic expander but must add trimethylbenzene (TMB), TMB has destroyed the order of material when enlarging the material pore volume.In addition, TMB is toxic, and is unfriendly to environment; Volatile, be unsuitable for industrial mass production.Eisenberg[Kui Yu, Adi Eisenberg ^*, Macromolecules, 1996,29,6359-6361] and co-workers by changing the composition of high-molecular block copolymer, the concentration of segmented copolymer, use different solvents, change the composition of solvent, add additive (salt, acid, alkali, homopolymer), change the temperature of synthetic system, pH value of solution value etc. obtains organic vesica.Pinnavaia[S.S.Kim; T.J.Pinnavaia, Science 1998,282,1302-1305] and co-workers utilize the gemini tensio-active agent to obtain the vesica of the silicon-dioxide of pore size distribution broad (20-1400nm), but its pore volume＜1cm ³/ g, and to add organic solvent.Chen Yongming [Jianzhong Du and Yongming Chen, Macromolecules 2004,37,5710-5716] etc. utilize the material of the organic and inorganic compounding of the hydrophilic and hydrophobic segment of special synthetic different lengths, the content that changes water is realized by ball and bar-shaped, arrives stratiform, rod and vesica (on a small quantity), to vesica and stratiform, the transformation of arriving vesica again, its raw material (making silicon source and template simultaneously) is so expensive can't the preparation in a large number.The present invention adopts P123 (EO ₂₀PO ₇₀EO ₂₀) (EO oxyethylene; The PO propylene oxide) etc. as template, silicon oxide vesicle, the foam of preparation large pore volume under the low temperature in buffered soln, its aperture is at 10-200nm, and pore volume is at 1.0-3.0cm ³In/g the scope, adjustable.

Summary of the invention

The purpose of this invention is to provide a kind of silicon oxide vesicle of large pore volume or foam and preparation method thereof.

The vesica or the foam of the large aperture capacity silicon oxide that the present invention proposes are a kind of employing sol-gel method synthetic under mild conditions, have large pore volume, controllable appearance (vesica, foam etc.), and the adjustable novel nano porous material in aperture.The mol ratio in tensio-active agent that it is used and silicon source is 0.01～0.05: 1, and the aperture is at 10-200nm, and pore volume is at 1.0-3.0cm ³In/g the scope, adjustable.

Large aperture capacity silicon oxide vesicle of the present invention or foamy preparation method are as follows:

(1) vesica, foamy preparation

Certain amount of surfactant is dissolved in the buffered soln, under agitation add the silicon source by a certain percentage: methyl silicate (TMOS) or tetraethoxy (TEOS), continue to stir 3-10 minute, and left standstill or continued to stir 20-48 hour, its each mol ratio of forming is:

Tensio-active agent: silicon source=0.01～0.05: 1 buffered soln: silicon source=100～350: 1;

Temperature of reaction system is 15-70 ℃.

(2) hydro-thermal, the mother liquor that step (1) is made under 80-130 ℃ of temperature hydro-thermal 20-36 hour.

(3) drying, with the product suction filtration after step (2) hydro-thermal, washing, flush away inorganic salt, drying at room temperature.

(4) removal of tensio-active agent at 400-900 ℃ of following roasting 4-8 hour, is removed tensio-active agent with dried product, makes product of the present invention.

Aforesaid tensio-active agent is poly-oxyethylene (PEO) as hydrophilic block, the long chain alkane nonionic surface active agent as hydrophobic group, and carbon atom number is 8-20, and the polymerization degree of oxyethylene is 4-100; Perhaps poly-oxyethylene (PEO) is as hydrophilic block, poly-propylene oxide (PPO) or poly-epoxy butylene (PBO) the block macromolecular tensio-active agent as hydrophobic block, and its molecular formula is EO _nPO _mEO _n, n=10-140, m=5-100, or EO _nBO _mEO _n, n=10-200, m=10-100, or EO _nBO _m, n=10-100, m=5-60.

Aforesaid buffered soln is the NaAc-HAc of pH value between 3-8, or NaOH-NaH ₂PO ₄Buffered soln uses inorganic salt to regulate and control the total ion concentration of buffered soln, and ionic concn is between 0.05-1.00M.

The present invention compared with prior art has following advantage:

(1) raw material is cheap and easy to get, and the reaction conditions gentleness is easy to operation.

(2) by change raw material ratio, temperature of reaction, pH value of solution value and and condition such as buffered soln total ion concentration can the modulation vesica, physicochemical property such as foamy pattern, aperture and pore volume.

(3) silicon oxide vesicle of gained, foam have bigger pore volume, illustrate as accompanying drawing, and prove to have good adsorption, sustained release performance by experiment.Material of the present invention is with a wide range of applications in fields such as absorption, support of the catalyst, medicament slow release, separation, chromatogram, pigment, microreactors.

Description of drawings

Fig. 1 is the transmission electron microscope picture of silicon oxide vesicle.

Fig. 2 is silicon oxide vesicle nitrogen adsorption-desorption isotherm.

Fig. 3 is a silicon-dioxide foamy transmission electron microscope picture.

Fig. 4 is silicon-dioxide foam nitrogen adsorption-desorption isotherm.

Embodiment

Embodiment 1

1g P123 is added 30g pH=5, Ac ^-Total ion concentration is a 0.2mol/L NaAC-HAc buffered soln, stirs P123 is dissolved fully under 40 ℃ of temperature, adds 1.52g TMOS in system, continues to stir 5 minutes, left standstill 24 hours, in 100 ℃ of hydro-thermals 24 hours, suction filtration, washing, drying was 550 ℃ of roastings 5 hours.Obtain foam materials.Aperture 40nm, pore volume 2.50cm ³/ g.

Embodiment 2

1g P123 is added 30g pH=5, Ac ^-Total ion concentration is the NaAC-HAc buffered soln of 0.2mol/L, stirring under 50 ℃ of temperature dissolves P123 fully, in system, add 1.52g TMOS, continue to stir 5 minutes, left standstill 24 hours, in 100 ℃ of hydro-thermals 24 hours, suction filtration, washing, drying was 550 ℃ of roastings 5 hours. obtain foam materials.Aperture 50nm, pore volume 2.20cm ³/ g.

Embodiment 3

1g P123 is added 30g pH=5, Ac ^-Total ion concentration is the NaAC-HAc buffered soln of 0.2mol/L, stirs P123 is dissolved fully under 60 ℃ of temperature, adds 1.52g TMOS in system, continues to stir 5 minutes, left standstill 24 hours, in 100 ℃ of hydro-thermals 24 hours, suction filtration, washing, drying was 550 ℃ of roastings 5 hours.Obtain foam materials.Aperture 40nm, pore volume 2.10cm ³/ g.

Embodiment 4

1g P123 is added 30g pH=6, Na ⁺Total ion concentration is the NaOH-NaH of 0.2mol/L ₂PO ₄Buffered soln stirs under 40 ℃ of temperature P123 is dissolved fully, adds 1.52g TMOS in system, continues to stir 5 minutes, left standstill 24 hours, and in 100 ℃ of hydro-thermals 24 hours, suction filtration, washing, drying was 550 ℃ of roastings 5 hours.Obtain foam materials.Aperture 30nm, pore volume 2.80cm ³/ g.

Embodiment 5

1g P123 is added 30g pH=5, Ac ^-Total ion concentration is the NaAC-HAc buffered soln of 0.05mol/L, stirs P123 is dissolved fully under 40 ℃ of temperature, adds 1.52g TMOS in system, continues to stir 5 minutes, left standstill 24 hours, in 100 ℃ of hydro-thermals 24 hours, suction filtration, washing, drying is at 550 ℃ of roasting 5h.Be and obtain the vesica material.Aperture 20-130nm, pore volume 1.82cm ³/ g.

Embodiment 6

1g P123 is added 30g pH=5, Ac ^-Total ion concentration is the NaAC-HAc buffered soln of 0.2mol/L, stirs P123 is dissolved fully under 40 ℃ of temperature, adds 2.08g TEOS in system, continues to stir 5 minutes, left standstill 24 hours, in 100 ℃ of hydro-thermals 24 hours, suction filtration, washing, drying was 550 ℃ of roastings 5 hours.Obtain foam materials.Aperture 100nm, pore volume 2.05cm ³/ g.

Claims

1, the preparation method of a kind of large aperture capacity silicon oxide vesicle or foam materials is characterized in that concrete steps are as follows:

(1) vesica, foamy preparation

Surfactant dissolves is gone into buffered soln, under agitation add the silicon source: methyl silicate or tetraethoxy, continue to stir 3-10 minute, leave standstill or continued to stir 20-48 hour, the mol ratio of its each component is:

Tensio-active agent: silicon source=0.01～0.05: 1 buffered soln: silicon source=100～350: 1

The temperature of reaction of system is 15-70 ℃;

(2) hydro-thermal, the mother liquor that step (1) is made under 80-130 ℃ of temperature hydro-thermal 20-36 hour;

(3) drying, with the product suction filtration after step (2) hydro-thermal, washing, the flush away inorganic salt, dry under the room temperature;

(4) removal of tensio-active agent at 400-900 ℃ of following roasting 4-8 hour, is removed tensio-active agent with dried product, promptly gets required silicon oxide vesicle or foam, and its aperture is at 10-200nm, and pore volume is at 1.0-3.0cm ³/ g.

2, large aperture capacity silicon oxide vesicle as claimed in claim 1 or foamy preparation method, it is characterized in that described tensio-active agent for poly-oxyethylene as hydrophilic block, long chain alkane nonionic surface active agent as hydrophobic group, carbon atom number is 8-20, and the polymerization degree of poly-oxyethylene is 4-100; Perhaps poly-oxyethylene is as hydrophilic block, poly-propylene oxide or the poly-epoxy butylene block macromolecular tensio-active agent as hydrophobic block, and its molecular formula is EO _nPO _mEO _n, n=10-140, m=5-100, or EO _nBO _mEO _n, n=10-200, m=10-100, or EO _nBO _m, n=10-100, m=5-60.

3, large aperture capacity silicon oxide vesicle as claimed in claim 1 or foamy preparation method is characterized in that described buffered soln is NaAc-HAc or the NaOH-NaH of pH=3-8 ₂PO ₄Buffered soln, and use inorganic salt to regulate and control the ionic concn of buffered soln, ionic concn is between 0.05-1.00M.