High-transparency low-hygroscopic material for LED package and preparation method thereof

Abstract

The application provides a high-transmittance and low-hygroscopic material for LED packaging, which is obtained by grafting modification of collagen polypeptide monolayer film G-STSocac with epoxy polysiloxane (PDMS-E) with a molecular weight of 1000, the grafting rate of the epoxy polysiloxane on the film is 1.7-2.0%, the contact angle is 115-126 DEG, the water resistance is that the weight loss rate after immersion in water for 2h is 0.006-0.011%, the high-temperature resistance is that the weight loss rate after standing for 2h under the condition of 150 DEG C plus or minus 5 DEG C is 0.002-0.005%, and the visible light transmittance is 94-98%. The high-transmittance and low-hygroscopic material for LED packaging has good light transmittance, low and controllable thickness, stable combination of epoxy polysiloxane and polypeptide monolayer film, and high chemical stability. Compared with the prior art, the coating can improve the adhesion of the coating on the material surface.

Description

Technical Field

[0001] This invention belongs to the field of LED packaging materials, specifically relating to a high light transmittance and low moisture absorption material for LED packaging and its preparation method. Background Technology

[0002] China is a major LED packaging country, with statistics showing that 80% of the world's LED device packaging is concentrated in China, distributed among various American, Taiwanese, Hong Kong, and domestic packaging companies. However, China lags far behind major countries like the US and Japan in LED packaging material research. The market for high-power LED packaging materials is completely dominated by Japanese and American products, leading to higher product costs, smaller profit margins, and, more importantly, severely hindering development. High-power LEDs not only require high sealing and light transmittance of packaging materials, but also demand the highest possible refractive index and adhesion, while also possessing certain low dielectric and mechanical properties. Currently, the most common packaging materials in the Chinese market include epoxy resin, polycarbonate, polymethyl methacrylate, glass, and silicone. Among these highly transparent materials, polymethyl methacrylate, polycarbonate, and glass are mainly used as outer lens materials, while epoxy resin and silicone can be used as both packaging materials and lens materials.

[0003] LED chip packaging diagram (e.g.) Figure 1 The adhesive, or bonding material, is the core of LED encapsulation. Located on top of the LED chip, it completely coats the chip, protecting it and reducing external vibrations. Therefore, LED encapsulation requires materials with high refractive index, good light transmittance, strong adhesion, sufficient hardness, and excellent mechanical properties. Epoxy resin, as an encapsulation material, has inherent hygroscopic properties, high cross-linking density after curing, high brittleness, high internal stress, and poor impact resistance.

[0004] Barton et al. (Research Progress on Aging Mechanism of White LEDs [J]. Foreign Electronic Components, 2007, (1) 8: 121) found that the temperature range of 135-145℃ can cause severe degradation of the resin, and the transparency of epoxy resin will decrease significantly at around 150℃, resulting in a significant reduction in the output of LED light and seriously affecting the service life of LED devices. Under the condition of high current, epoxy resin as an encapsulation material may even carbonize, forming a conductive channel on the surface of the LED device, causing the device to fail, thus greatly limiting the use of epoxy resin. Chinese patent document US5561174 introduces active end groups or side groups into epoxy resin through the reaction of polydimethylsiloxane, which significantly improves the heat resistance, internal stress and impact resistance of epoxy resin; although some of the shortcomings of epoxy resin as an LED encapsulation material can be improved by modifying epoxy resin, it still cannot meet the development needs of LED.

[0005] Especially with the development of high-power LEDs, the requirements for packaging materials are becoming increasingly stringent. Therefore, there is an urgent need to develop new packaging materials with high refractive index and high transparency to meet market demands. Silicone materials have high light transmittance, good thermal stability, strong UV resistance, low internal stress, and very low hygroscopicity. Therefore, silicone materials have received considerable attention in recent years as a next-generation packaging material for high-power LEDs. However, existing technologies for preparing packaging material coatings using silicone materials suffer from problems such as excessively thick films, susceptibility to cracking, poor coating adhesion, and difficulty in controlling film thickness. Summary of the Invention

[0006] To address the aforementioned problems in the prior art, this invention provides a high-transmittance, low-moisture-absorbing material for LED packaging and its preparation method.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A high-transmittance, low-moisture-absorbing material for LED encapsulation is characterized by grafting a collagen polypeptide monolayer membrane G-STCocac with an epoxy polysiloxane (PDMS-E) of molecular weight 1000. The grafting rate of the epoxy polysiloxane on the membrane is 1.7–2.0%, and the contact angle is 115–126°. The membrane exhibits the following properties: water resistance (weight loss of 0.006–0.011% after immersion in water for 2 hours); high-temperature resistance (weight loss of 0.002–0.005% after standing at 150±5℃ for 2 hours); and visible light transmittance of 94–98%.

[0009] Light transmittance indicates the ability of light to pass through a medium; it is the percentage of luminous flux passing through a transparent or translucent body relative to the incident luminous flux. The coating of this invention has a light transmittance of 94-98% in the range of 400-800 nm; 95-98% in the range of 450-780 nm; and 94-97% in the range of 400-450 nm.

[0010] The grafting rate is defined as follows:

[0011] The percentage change in the molar amount of primary amino groups on the membrane before and after the grafting reaction relative to the molar amount of primary amino groups on the membrane before the grafting reaction.

[0012] The change in the molar amount of primary amino groups on the membrane before and after the grafting reaction can be measured by (W D The molar amount of successfully grafted epoxy polysiloxane is calculated as W0) / 1000. D W0 represents the mass of the polypeptide monolayer membrane after grafting with epoxy polysiloxane, while W0 represents the mass of the polypeptide monolayer membrane before grafting with epoxy polysiloxane.

[0013] The molecular formula of the epoxy polysiloxane is as follows:

[0014]

[0015] Preferably, the collagen polypeptide monolayer membrane G-STSocac is composed of molecules with a molecular weight of (1.48±0.2)×10⁻⁶. 5 The membrane is composed of g / mol of polypeptide molecules, with a thickness of 8.5 nm, a primary amino group exposure of 11.60% on the membrane surface, and a zeta potential of -8.75 mV; the contact angle of the membrane is 61°.

[0016] More preferably, the secondary structure of the collagen polypeptide monolayer membrane G-STSocac is as follows: α-helix 29.66±0.1%; β-sheet 18.98±0.15%; β-turn 7.93±0.05%; random coil 43.44±0.26%.

[0017] More preferably, the preparation method of the polypeptide monolayer membrane G-STSocac is as follows:

[0018] (1) Prepare a polypeptide solution at 50℃, and then add sodium tetradecyl sulfonate (STSo) to obtain a polypeptide-STSo mixed solution with an STSo concentration of 2.5 mmol / L. Keep it warm for later use.

[0019] (2) Immerse the substrate material in a mixed acid solution, rinse until neutral, blow dry with nitrogen and then dry it.

[0020] (3) After the dried substrate material is immersed in a polyethyleneimine (PEI) aqueous solution, it is rinsed with water, dried with nitrogen gas, and then dried again to obtain a positively ionized substrate material with PEI deposited on it.

[0021] (4) Immerse the positively ionized substrate material in the polypeptide-STSo mixed solution obtained in step (1) and deposit for 8 to 12 minutes. Then, lift it in deionized water 20 to 25 times and dry it with high-purity nitrogen to obtain the polypeptide monolayer G-STSo.

[0022] Preferably, the substrate material in step (2) is a metal, rubber, or glass. Preferably, the substrate material is a glass sheet.

[0023] This invention also provides a method for preparing the above-mentioned high light transmittance and low moisture absorption material for LED packaging, characterized by comprising the following steps:

[0024] 1) Add epoxy polysiloxane with a molecular weight of 1000 to sodium carbonate / sodium bicarbonate buffer solution and disperse by ultrasonication to obtain a mixed solution;

[0025] 2) Place the collagen polypeptide monolayer membrane G-STSocac in the mixed solution described in step 1) for 1 to 3 hours at a temperature of 48 to 52°C;

[0026] 3) The collagen polypeptide monolayer membrane G-STSocac treated in step 2) was repeatedly lifted in acetone to remove unreacted epoxy polysiloxane, dried with high-purity nitrogen, and then stored in nitrogen.

[0027] Preferably, the pH of the sodium carbonate / sodium bicarbonate buffer solution in step 1) is 9.6.

[0028] Preferably, the concentration of epoxy polysiloxane in the mixed solution in step 1) is 0.009–0.02 mol / L.

[0029] The beneficial effects of this invention are:

[0030] The high-transmittance, low-moisture-absorbing material for LED packaging provided by this invention exhibits excellent light transmittance, low and controllable thickness, and a stable bond between the epoxy polysiloxane and the polypeptide monolayer film, resulting in high chemical stability. Compared with existing technologies, this coating improves the adhesion of the coating to the material surface. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of LED chip packaging;

[0032] Figure 2 It is G-STCoca-(PDMS-E) 1000 Surface morphology diagrams of the coating (a, Example 3, b, Example 1);

[0033] Figure 3 These are 3D morphology images of the material surface (aG-STSocac, b, Example 3, c, Example 1);

[0034] Figure 4 The transmittance of G-STSocac-(PDMS-E1000) is (a, Example 1, b, Example 2, c, Example 3, d, Comparative Example 1, e, Comparative Example 2);

[0035] Figure 5 These are optical microscope images of the G-STSocac-(PDMS-E1000) sample obtained in Example 1 after being placed in an oven for different times (a, irradiation 0h, b, irradiation 1h, c, irradiation 2h);

[0036] Figure 6 These are optical microscope images of the G-STSocac-(PDMS-E1000) sample obtained in Example 1 after being placed in an oven for different times (a, irradiation 0h, b, irradiation 1h, c, irradiation 2h). Detailed Implementation

[0037] The collagen peptides used in the embodiments of this invention are commercially available peptide products (AR) with a molecular weight of approximately 5.00 × 10⁻⁶. 4 The polypeptide with a molecular weight of ~1.80×10⁵ g / mol, obtained by dialysis, is (1.48±0.2)×10⁵ g / mol. 5 g / mol. 1g of collagen polypeptide contains 5.6 × 10 g of primary amino groups. -4 mol. All other reagents, unless otherwise specified, are commercially available products.

[0038] The preparation method of the epoxy polysiloxane used in this invention can be found in: Zhu C, Xu J, Hou Z, et al. Scale Effect on Interface Reaction between PDMS-E Emulsion Droplets and Gelatin[J]. Langmuir, 2017. The weight-average molecular weight of the epoxy polysiloxane used in this invention is 1000±50.

[0039] Example 1

[0040] A high-transmittance, low-moisture-absorbing material for LED encapsulation includes the following steps:

[0041] S1: Preparation of the polypeptide monolayer membrane G-STSocac can be referred to Chinese patent document CN 111842088 A (202010753400.5).

[0042] (1) Prepare 50 mL of collagen polypeptide solution with a concentration of 4%wt: Accurately weigh collagen polypeptide into 100 mL of three-necked flask, accurately measure deionized water, pour the deionized water into the three-necked flask, let it swell at room temperature for 0.5 h, then put the three-necked flask into a water bath at 50±1℃, heat and stir for 2 h to completely dissolve it, then adjust the pH of the solution to 10.00±0.02 with 2 mol / L sodium hydroxide, and stabilize it in the water bath for 0.5 h.

[0043] (2) Add surfactant STSo to the above collagen peptide solution to obtain a collagen peptide-STSo mixed solution with a concentration of 2.5 mmol / L (CAC, the critical aggregation concentration of STSo at 50℃); stabilize in a water bath for 6 hours for later use.

[0044] (3) Cut several square glass slides with a size of 1cm×1cm×1mm and a thickness of 1mm. Clean the glass slides with deionized water, anhydrous ethanol, and acetone by ultrasonication for 15min each, then dry them with high-purity nitrogen and dry them in an oven at 60℃ for 12h for later use. Prepare a mixed acid solution with a volume ratio of 30% H2O2 and 98% H2SO4 of 1:1. After cooling to room temperature, treat the above-treated glass slides with the mixed acid solution for 1h, then rinse them with tap water until neutral, then rinse them with deionized water 5 times, and finally dry them with high-purity nitrogen and dry them in an oven at 60℃ for 12h for later use.

[0045] (4) Prepare a 1 mg / mL PEI-polyethyleneimine aqueous solution. Treat the acid-etched glass slides with the PEI solution at room temperature for 0.5 h, then wash them 5 times with deionized water to remove loosely bound charges. Finally, dry them with high-purity nitrogen and then in an oven at 60 °C for 12 h for later use. Place the positively ionized glass slides into a deposition chamber, pour in the prepared peptide solutions of different systems, and deposit them at 50 °C for 10 min. Then, lift them 20 times in deionized water, dry them with high-purity nitrogen, and store them in nitrogen. The resulting peptide monolayer membrane is labeled G-STSocac.

[0046] S2: Preparation of G-STSocac-(PDMS-E1000), a high-transmittance, low-moisture-absorbing material for LED packaging.

[0047] 1) An epoxy polysiloxane with a molecular weight of 1000 was ultrasonically treated for 15 min and dispersed in a sodium carbonate / sodium bicarbonate buffer (pH=9.6) to obtain a mixed solution; the concentration of epoxy polysiloxane in the mixed solution was 0.01146 mol / L.

[0048] 2) Place the collagen polypeptide monolayer membrane G-STSocmc in the above mixed solution for 2 hours at a temperature of 50℃;

[0049] 3) The collagen polypeptide monolayer membrane G-STSocmc obtained in step 2) was lifted 10 times in acetone to remove unreacted epoxy siloxane, dried with high-purity nitrogen, and then stored in nitrogen. Multiple samples were prepared simultaneously under the same conditions. Although there may be slight differences in grafting rates, this does not affect the performance or the environment in which it is used, and is within the error range.

[0050] The grafting rate of PDMS-E in the obtained G-STSocac-(PDMS-E1000) coating material was 1.940%, and the contact angle was 125.76°.

[0051] Example 2

[0052] A high-transmittance, low-moisture-absorbing material for LED encapsulation includes the following steps: Unlike Example 1, the concentration of epoxy polysiloxane in the mixed solution is 0.009168 mol / L.

[0053] The grafting rate of the obtained G-STSocac-(PDMS-E1000) coating material was 1.823%, and the contact angle was 119.37°.

[0054] Example 3

[0055] A high-transmittance, low-moisture-absorbing material for LED encapsulation includes the following steps: Unlike Example 1, the grafting time is changed to 1 hour.

[0056] The grafting rate of the obtained G-STSocac-(PDMS-E1000) coating material was 1.715%, and the contact angle was 115.7°.

[0057] Comparative Example 1

[0058] G-STSo, a material for LED packaging 6％wt The preparation method of (PDMS-E1000) differs from that in Example 1 in that the concentration of the surfactant in step (2) is 7.96 (6% wt) mmol / L; and the concentration of the epoxy polysiloxane in step (2) is 0.0112 mol / L. The grafting rate of this product is 3.638%, and the contact angle is 135.62°.

[0059] Comparative Example 2

[0060] An LED encapsulation material is prepared by mixing 5g of gelatin with water and heating to 50°C until the gelatin is completely dissolved. Sodium hydroxide is then added to adjust the pH to 10.0, resulting in a 5% (w / w) gelatin solution. Sodium tetradecyl sulfate (2.5 mmol / L) is added as an emulsifier, and stirring continues until completely dissolved. Then, 0.052g of epoxy polysiloxane (Mw = 1000) is added continuously or in batches, and the reaction is allowed to proceed for 24 hours. Stirring and heating are then stopped, yielding an epoxy polysiloxane-modified gelatin solution. A positively ionized glass slide is placed in the modified gelatin solution and deposited at 50°C for 10 minutes. The slide is then lifted 20 times in deionized water, dried with high-purity nitrogen, and stored in nitrogen to obtain a coating. The contact angle of this coating is 113°.

[0061] Performance testing and characterization

[0062] 1. Morphological characteristics

[0063] The surface smoothness of the coating of this invention was measured by a Multimode8 AFM (Bruker, Germany). The prepared sample was placed on the worktable, and the morphology and smoothness of the sample were characterized in Peak Force mode. During the test, the boundary was first found using the optical auxiliary system of the atomic force microscope, and then the test range was set to 20 μm to span the sample area. The AFM tip was used for scanning at a speed of 0.977 Hz and a scanning range of 1 μm. The data processing software was NanoScope Analysis, which is included with the AFM.

[0064] from Figure 2 , 3 It can be seen that G-STSocac grafted with PDMS-E 1000 The changes in surface morphology and smoothness before and after grafting: the average surface roughness Ra = 8.25 nm after 1 hour of grafting, and Ra = 8.37 nm after 2 hours of grafting. The surface roughness differs very little at different grafting times, but from... Figure 3 It can be seen that the surface particles are more uniformly and orderly accumulated 2 hours after grafting, and the coating surface is smoother.

[0065] 2. Moisture absorption rate test

[0066] The samples (Example 1, Example 2, Example 3, Comparative Example 1, and Comparative Example 2) were accurately weighed using a quartz crystal microbalance, and then placed in 25 mL beakers with 25 mL of distilled water (25°C). After standing for 30 min, 60 min, 90 min, and 120 min, respectively, they were dried with nitrogen gas and accurately weighed using a quartz crystal microbalance to calculate the weight loss rate.

[0067] Table 1. Mass changes of samples after soaking in distilled water for different times.

[0068]

[0069] As can be seen from Table 1, the mass changes of Examples 1 to 3 after soaking in distilled water were very small, while the mass changes of Comparative Examples 1 and 2 before and after treatment were larger than those of Examples 1 to 3, which further reflects that the coating G-STSocac-(PDMS-E1000) has good water resistance.

[0070] 3. Light transmittance test

[0071] A transmittance meter, also known as a light transmittance analyzer, is primarily used to measure the visible light transmittance of automotive glass, various types of glass, acrylic, films, plastics, and transparent and translucent objects. The SDR851 test principle involves illuminating the transparent material under test with ultraviolet, infrared, and visible light sources. Sensors detect the incident light intensity and the light intensity transmitted through the material, respectively. The ratio of transmitted light intensity to incident light intensity is the transmittance, expressed as a percentage. It is specifically designed for testing the optical transmittance of transparent materials such as eyeglass lenses, glass, coatings, organic materials, and paints. The test light used in this invention is visible light, covering the entire wavelength range of 380nm to 760nm.

[0072] The transmittance of the coating samples obtained under the conditions of Example 1, Example 2, Example 3, Comparative Example 1, and Comparative Example 2 was tested using an SDR851 desktop optical transmittance meter (model: ZW-LS108H, resolution: 0.1%, power supply: 5VAC / DC) at visible light wavelengths (380nm-780nm). The test results are as follows. Figure 4 As shown.

[0073] Because the coating prepared in this invention is an ultrathin layer (tens of nanometers), it cannot be peeled off from the glass. Therefore, the transmittance of the coating is tested along with the glass sheet. The glass used in this invention is plexiglass, with a transmittance of 98%. Therefore, the actual transmittance of the coating in this invention should be the transmittance of the test sample (glass plus ultrathin coating) plus 2%.

[0074] Depend on Figure 4It can be seen that the transmittance of Examples 1, 2, and 3 reached over 95% in the 450–780 nm range, and over 94% in the 400–780 nm range, ranging from 94% to 98%, which meets the transmittance requirements of power LED encapsulation materials. Comparative Examples 1 and 2 had lower transmittance in the 450–780 nm range than Examples 1, 2, and 3, but still reached over 92%, ranging from 92% to 95%; however, their transmittance in the 400–450 nm range was below 94%, ranging from 90% to 94%.

[0075] 4. Heat resistance

[0076] The samples (prepared under the conditions of Examples 1, 2, 3, Comparative Example 1, and Comparative Example 2) were placed in an electrically heated drying oven (Shanghai Heng Scientific Instruments Co., Ltd.) at 150±5℃ for 0h, 1h, and 2h, respectively, and then removed. The samples were photographed and compared using an optical microscope at 100X and 400X, and finally, the mass was accurately weighed using a quartz crystal microbalance.

[0077] Table 2. Mass changes of different samples at different times at 150±5℃

[0078]

[0079] As can be seen from optical microscope images 5 and 6, the surface of the coating after heat treatment has very little change and is uniform. The mass of the ultrasonically treated sample was accurately weighed using a quartz crystal microbalance. As can be seen from Table 2, the mass change of Examples 1 to 3 is very small, while the mass change of Comparative Examples 1 and 2 before and after treatment is larger than that of Examples 1 to 3. This further reflects that the G-STSocac-(PDMS-E1000) coating has certain heat resistance and can meet the usage environment of LED packaging materials.

[0080] The results above show that this invention, by preparing a polypeptide monolayer membrane from gelatin in the presence of sodium tetradecyl sulfate (STSO) at a concentration of 2.5 mmol / L, and then grafting it with an epoxy polysiloxane with a molecular weight of 1000, can not only control the membrane thickness at the nanometer level but also improve the material's light transmittance and water resistance. This indicates that the structure and properties of the polypeptide monolayer membrane are altered to some extent compared to the gelatin polymer, and the grafting with an epoxy polysiloxane of a certain molecular weight produces unexpected changes in membrane performance. Furthermore, the grafting method of first modifying the gelatin before grafting makes it difficult to control the grafting rate, resulting in ungrafted epoxy polysiloxane in the coating. Some of this ungrafted epoxy polysiloxane easily dissolves during elution, affecting the membrane's stability and adhesion. The undissolved portion is prone to dissolution and seepage during subsequent use, exhibiting poor chemical stability.

Claims

1. A high-transmittance, low-moisture-absorbing material for LED encapsulation, characterized in that, The collagen polypeptide monolayer membrane G-STSocac was grafted with epoxy polysiloxane (PDMS-E) with a molecular weight of 1000. The grafting rate of epoxy polysiloxane on the membrane was 1.7~2.0%, and the contact angle was 115~126°. Water resistance: the weight loss rate after immersion in water for 2 hours was 0.006~0.011%. High temperature resistance: At 150±5℃, the weight loss after standing for 2 hours is 0.002~0.005%; visible light transmittance is 94~98%. The collagen polypeptide monolayer G-STSocac is composed of molecules with a molecular weight of (1.48±0.2)×10⁻⁶. 5 The monolayer membrane is composed of g / mol of polypeptide molecules, with a thickness of 8.5 nm, a primary amine exposure of 11.60% on the membrane surface, and a zeta potential of -8.75 mV. The contact angle of the membrane is 61°. The secondary structure of the collagen polypeptide monolayer membrane G-STSocac is as follows: α-helix 29.66±0.1%; β-sheet 18.98±0.15%; β-turn 7.93±0.05%; random coil 43.44±0.26%. The grafting rate is defined as follows: The percentage change in the molar amount of primary amino groups on the membrane before and after the grafting reaction relative to the molar amount of primary amino groups on the membrane before the grafting reaction. The change in the molar amount of primary amino groups on the membrane before and after the grafting reaction is measured by (W D The molar amount of successfully grafted epoxy polysiloxane is calculated as W(0) / 1000; where W... D W0 represents the mass of the polypeptide monolayer membrane after grafting with epoxy polysiloxane, while W0 represents the mass of the polypeptide monolayer membrane before grafting with epoxy polysiloxane. The molecular formula of the epoxy polysiloxane is shown below: 。 2. The material according to claim 1, characterized in that, The wavelength of visible light is 780–400 nm.

3. The material according to claim 1, characterized in that, The preparation method of the polypeptide monolayer G-STSocac is as follows: (1) Prepare a polypeptide solution at 50℃, and then add the surfactant sodium tetradecyl sulfonate (STSo) to obtain a polypeptide-STSo mixed solution with an STSo concentration of 2.5 mmol / L. Keep it warm for later use. (2) Immerse the substrate material in a mixed acid solution, rinse until neutral, blow dry with nitrogen and then dry it. (3) After the dried substrate material is immersed in a polyethyleneimine (PEI) aqueous solution, it is rinsed with water, dried with nitrogen gas, and then dried again to obtain a positively ionized substrate material with PEI deposited on it. (4) Immerse the positively ionized substrate material in the polypeptide-STSo mixed solution obtained in step (1) and deposit for 8~12 min. Then, lift it in deionized water 20~25 times and blow it dry with high-purity nitrogen to obtain the polypeptide monolayer membrane G-STSoac.

4. The material according to claim 3, characterized in that, The substrate material in step (2) is metal, rubber or glass.

5. The material according to claim 4, characterized in that, The substrate material is a glass sheet.

6. The method for preparing the high-transmittance, low-moisture-absorbing material for LED encapsulation according to any one of claims 1 to 5, characterized in that, Includes the following steps: 1) Add epoxy polysiloxane with a molecular weight of 1000 to sodium carbonate-sodium bicarbonate buffer solution and disperse by ultrasonication to obtain a mixed solution; 2) Place the collagen polypeptide monolayer membrane G-STSocac in the mixed solution described in step 1) for 1-3 hours at a temperature of 48-52℃; 3) The collagen polypeptide monolayer membrane G-STSocac treated in step 2) was repeatedly lifted in acetone to remove unreacted epoxy polysiloxane, dried with high-purity nitrogen, and then stored in nitrogen.

7. The preparation method according to claim 6, characterized in that, The pH of the sodium carbonate-sodium bicarbonate buffer solution described in step 1) is 9.

6.

8. The preparation method according to claim 6, characterized in that, The concentration of epoxy polysiloxane in the mixed solution described in step 1) is 0.009~0.02 mol / L.

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