A kind of encapsulation preparation method of high stability nano silver wire laminated film
Technical field
The present invention relates to a kind of transparent conductive film, especially relate to the encapsulation preparation method of a kind of nano silver wire laminated film。
Background technology
At present, nano silver wire is because unique optical, electrical physical property, and is with a wide range of applications, as thin-film solar cells, touch screen show, light emitting diode, fexible film display etc.。In addition, nano silver wire has the special nature that the other materials such as the electric conductivity of excellence, stronger absorbability, good biocompatibility are incomparable, and it is used to prepare transparent conductive film, substitute traditional tin indium oxide (ITO) transparent electrode material。
Traditional tin indium oxide is because making consumption be gradually increased, and the ore reserve of tin indium oxide is abundant not, causes cost price to rise every year。When using tin indium oxide to prepare transparency electrode, often owing to bending crimping causes the surface film micro area fracture of thin film and broken, add sheet resistance, there is the problem being difficult to use in the electronic machine that flexible bending conducts electricity。In addition prepare traditional ito thin film generally require use require that high complex device instrument causes with high costs to vacuum sputtering, evaporation etc.。
In recent years, researcher finds to adopt the transparent conductive film prepared of nano silver wire material to have excellent electric conductivity, transmitance and resistance to bending performance, also expose corresponding problem simultaneously, and such as corrosion-resistant, oxidation resistance is poor, contact resistance is high and substrate adhesion is poor etc.。
Although the electrogilding film adopted in the preparation process of nano silver wire thin film and hot-pressing processing can effectively reduce the contact resistance between the network-like portal structure of nano silver wire, but nano silver wire network bridge shelf structure nano wire in matrix surface coated film easily comes off and does not demonstrate flexibility and mechanical stability simultaneously。Some equipment specially requires transmittance and reaches 90% its surface resistance lower than 30 Ω/sq, still have much challenging。
CN102087886A proposes first to be coated with a layer binder at substrate surface, and as used PVA as coat, but this way can increase the square resistance of coating。CN104882223A proposes a kind of graphene oxide and nano silver wire composite transparent conductive film and manufacture method, needs substrate surface is carried out Cement Composite Treated by Plasma, to adopt hot pressing nano silver wire conductive layer processing mode simultaneously in its technical process。Adopt this technique will increase the difficulty processing technique, and the use of maximization process equipment can increase cost undoubtedly, simultaneously the lifting limited efficiency of nano silver wire transparent conductive film and substrate adhesion in said method。
Therefore, this area is badly in need of a kind of can effectively improving corrosion resistance, oxidation resistance, reduction contact resistance, the preparation method with the transparent conductive film of long-time stability。
Summary of the invention
The present invention is for avoiding above-mentioned the deficiencies in the prior art part, it is provided that the encapsulation preparation method of a kind of high stability nano silver wire laminated film, it is intended to effective raising its corrosion resistance, oxidation resistance, reduction contact resistance。
This invention address that technical problem, adopt the following technical scheme that
The encapsulation preparation method of the high stability nano silver wire laminated film of the present invention, it is characterized in that and comprises the steps:
A, preparation nano silver wire soldering fluid:
With silver nitrate and glucose be solute, with ethanol for solvent, prepare mixed solution, then regulate pH value to 1-5, it is thus achieved that nano silver wire soldering fluid;
B, dispersion nano silver wire
Nano silver wire is disperseed in ethanol, it is thus achieved that nano silver wire alcohol dispersion liquid;Nano silver wire alcohol dispersion liquid is coated on the positive and negative of substrate, forms network-like nano silver wire structure;Wherein, nano silver wire can be prepared by alcohol reducing process, is centrifuged screening, sieves again through solvent after adding acetone or ethyl acetate sedimentation。
C, nano silver wire is welded
At 20~80 DEG C, using described soldering fluid soak or infiltrate described substrate 20~180 minutes, make each nano silver wire of composition network-like nano silver wire structure react at the place of being overlapped mutually, dissolves each other in local, thus realizing being welded to each other;Substrate is dried in vacuum drying oven, in substrate, namely forms soldered network-like nano silver wire structure;
D, encapsulation
Light-cured resin is sprayed on the network-like nano silver wire structure top layer of substrate positive and negative, is then passed through namely obtaining nano silver wire laminated film after 250~300nm length ultraviolet line irradiates。
Preferably, in described nano silver wire soldering fluid, silver nitrate concentration is 1mmoL/L~1moL/L, and concentration of glucose is 1mmoL/L~1moL/L。
Preferably, the pH value of described nano silver wire soldering fluid is regulated by concentrated nitric acid and/or sodium hydroxide powder body。The mass fraction of concentrated nitric acid used is 65%, and the powder body of sodium hydroxide used is analytical pure, and mass fraction is more than 96%。
Preferably, described light-cured resin is aqueous UV epoxy acrylate, aqueous UV urethane acrylate, aqueous UV polyester acrylate, aqueous UV polyethers propylene, aqueous UV pure acrylic resin, aqueous UV epoxy resin or aqueous UV silicone oligomer。
Preferably, the diameter of described nano silver wire is 1-100 nanometer, and length is 20 microns~200 microns, and draw ratio is 500~1000。
Preferably, described substrate is PET, PVC, single-layer graphene, lucite or thin polymer film。
As it is shown in figure 1, the packaged type of nano silver wire laminated film of the present invention is ecto-entad is outwards followed successively by light-cured resin, nano silver wire, substrate, nano silver wire, light-cured resin again。
The Fundamentals of Welding of the present invention are: utilize one-dimensional nano line to be overlapped mutually the interfacial energy at place when forming network and taking bridge-like structure higher, utilize connatural chemical reaction liquid to react at contact interface, dissolve each other and reach one-dimensional material and be welded to each other purpose in local, thus reducing the contact resistance of thin film。
The present invention adopts photosensitive resin as filmogen, coating encapsulation silver nanowire layer, and isolation air contact prevents Oxidation, simultaneously because the attachment of resinous material, it is possible to the erosion-resisting ability of effective lifting。
Beneficial effects of the present invention is embodied in:
1, the encapsulation preparation method of nano silver wire laminated film provided by the invention, the network-like nano silver wire formed putting up a bridge obtains rock-steady structure through chemistry soldering, adopts light-cured resin as encapsulated layer simultaneously, uses irradiation under ultraviolet ray to generate insoluble film;Being compared to tradition coating method, the method for the present invention can effectively reduce interface contact resistance, increases oxidation resistance and resistance to corrosion, improves the adhesiveness with substrate。
2, nano silver wire soldering fluid provided by the invention and be welded into film method, it is possible to the effective welding network-like portal structure of nano silver wire, reduces contact resistance, increases stability;The solder joint of welding position is little simultaneously, precision is high。
3, operational approach provided by the invention is relatively low to the requirement degree of large-scale and complicated device, it is not necessary to uses plasma treatment substrate and hot-press equipment to process conductive layer, reduces the requirement to equipment cost。
Accompanying drawing explanation
Fig. 1 is the encapsulation mode schematic diagram that the present invention adopts。
Fig. 2 is the scanning electron microscope diagram that the present invention obtains nano silver wire rock-steady structure after soldering。
Fig. 3 be the embodiment of the present invention 1 preparation with the optical microscope photograph of the PET nano silver wire laminated film being substrate。
Fig. 4 be the embodiment of the present invention 1 preparation with the PET nano silver wire laminated film actual effect figure being substrate。
Detailed description of the invention
Technical scheme is done and is set forth explanation clearly by embodiment presented below and accompanying drawing。
The encapsulation preparation of nano silver wire laminated film of the present invention carries out as follows:
A, preparation nano silver wire soldering fluid:
With ethanol for solvent, compound concentration is the silver nitrate solution of 10mmol/L and concentration is the glucose solution of 10mmol/L respectively;
Taking after silver nitrate solution 10mL and glucose solution 10mL shakes up mixing, add concentrated nitric acid that 1mL mass fraction is 65% and the sodium hydroxide powder body that 0.09g mass fraction is 96% shakes up again, recording its pH value is 1.7, it is thus achieved that nano silver wire soldering fluid;
B, dispersion nano silver wire
Take the polyvinylpyrrolidone ethylene glycol solution that 50mL concentration is 20mmol/L and the silver nitrate ethylene glycol solution that 30mL concentration is 15mmol/L, add 0.0096g potassium bromide, room temperature mix and blend 30 minutes, then after 170 DEG C of insulation reaction 1.5h, take out reactant liquor。Take the deionized water that 10mL reactant liquor adds 10mL, the acetone adding 20mL settles, after sedimentation 1h, 6000rpm is centrifuged 20 minutes again, take centrifugal sediment and add mistake 2000 mesh sieves after 50mL ethanol shakes up, take oversize and add 30mL ethanol recentrifuge, after repeating screening centrifugally operated 2-3 time, take centrifuged deposit thing addition ethanol, be configured to the nano silver wire alcohol dispersion liquid of 20mg/mL;
Nano silver wire alcohol dispersion liquid is coated on the positive and negative of substrate, forms network-like nano silver wire structure;
C, nano silver wire is welded
Using the step a nano silver wire soldering fluid prepared infiltration substrate, make base reservoir temperature keep 20min at 25 DEG C simultaneously, each nano silver wire reacts at the place of being overlapped mutually, and dissolves each other in local, thus realizing being welded to each other;Substrate is dried in vacuum drying oven (80 DEG C are dried 90min), in substrate, namely forms soldered network-like nano silver wire structure (as shown in Figure 2);
D, encapsulation
Take 10g light-cured resin to add in 90g deionized water, repeat to stir, be then sprayed on the network-like nano silver wire structure top layer of substrate positive and negative, after being then passed through 250~300nm length ultraviolet line irradiation 2h, namely obtain nano silver wire laminated film。
Said method gives concrete operation step prepared by nano silver wire thin-film package, other operating process, as nano silver wire alcohol dispersion liquid coating method on matrix can choose at random spin coating, blade coating, dip-coating, spraying etc., the selection of light-cured resin can also carry out phase immiscible and replacing and use。
The embodiment 1~12 provided such as table 1 provides the nano silver wire laminated film (wherein the sample of embodiment 1 is as shown in Figure 3) under different encapsulation preparation condition, and its operating process is same as mentioned above, and only in table, parameter does adaptation adjustment。Wherein do not carry out soldering, namely do not carry out the immersion in step a and step c or infiltration (but the drying in vacuum drying oven still carries out);Do not encapsulate and namely do not carry out step d。
The experiment condition of table 1 embodiment 1~12
Performance test:
Nano silver wire conductive film prepared by embodiment 1~12 is carried out following test respectively:
(1) square resistance: adopt four probe method to measure the square resistance of nano silver wire conductive layer;
(2) resistance to adhesive tape sticking performance: Scotch adhesive tape (3M) is pasted on sample surfaces, adhesive tape is firmly rubbed to ensure coating and adhesive tape comprehensive engagement with finger tip, then plus the weight of 1kg on sample, after 1min, arrest one end that adhesive tape is unsettled, and with the angle of 60 °, in 1s, smoothly tear off adhesive tape, then measure its electric conductivity by four probe method;
(3) high-temp resisting high-humidity resisting degree performance: sample is placed in relative humidity be 90%, temperature be the climatic chamber (KCL-2000W of 60 DEG C, TOKYORIKAKIKAICo., LTD) in, after a period of time, sample is taken out, and after ambient temperatare puts 24h, measure its electric conductivity by four probe method。
(4) bend resistance fatigue behaviour: be fixed on drawing stand by the two ends of sample and carry out bi-directional compression, compression speed is 1.5mm/min, stops compression when compressive deformation reaches 100% and recovers deformation to 0%, in this, as once bending;Then repeat above-mentioned bending experiment, test the electric conductivity under 1000 bending number of times;
(5) transmitance: be the light transmittance of 550nm in optical wavelength by ultraviolet/visible/near infrared spectrophotometer (Lambda950) test sample;
(6) conductive stability test: use DC source to provide 3V, 2A follow current, thin film sets and is cut to width 2cm, length 15cm, continuance test square resistance, records required time when square resistance varies more than 2 times。
Above-mentioned test result is as shown in table 2。
The performance test results of table 2 embodiment 1~12。
Be can be seen that by embodiment 1~12, through the nano silver wire thin film of soldering and packaging technology, its square resistance, resistance to adhesive tape sticking performance, high-temp resisting high-humidity resisting degree performance, bend resistance fatigue behaviour, conductive stability are better than the packaging film not carried out and do not carry out the thin film of soldering and encapsulation。Be can be seen that in light-cured resin raw materials different on identical base material by embodiment 1,4,7,10 and carry out the square resistance that film-forming process obtains, aqueous UV epoxy acrylate is more outstanding, identical encapsulating material uses different base materials, show that the transmitance of PET base material is outstanding。By comparative example 1,2,3 groups, embodiment 4,5,6 groups, embodiment 7,8,9 groups, embodiment 10,11,12 groups can draw, the thin film not being packaged substantially is deteriorated in resistance to adhesive tape sticking performance, high-temp resisting high-humidity resisting degree performance, bend resistance fatigue behaviour, and the thin film after soldering has lifting by a relatively large margin in conductive stability is tested。
Last it is noted that obvious, above-described embodiment is only for clearly demonstrating example of the present invention, and is not the restriction to embodiment。For those of ordinary skill in the field, can also make other changes in different forms on the basis of the above description。Here without also cannot all of embodiment be given exhaustive。And the apparent change thus amplified out or variation are still among protection scope of the present invention。