In-situ preparation method for polymer wrinkled surface
By reacting alkyl trichlorosilane with aqueous polymer coating, a controllable polymer wrinkle surface is prepared, which solves the problems of poor preparation complexity and reliability in the prior art, and realizes structural diversification and low-cost polymer wrinkle surface application.
Patent Information
- Application Number
- CN202311319147.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-10-12
- Publication Date
- 2025-07-11
- Estimated Expiration
- 2043-10-12
AI Technical Summary
The prior art has problems such as complex process, high matrix requirements, difficulty in preparing polymer wrinkled surfaces, poor reliability and single surface structure when preparing polymer wrinkled surfaces, which limits its application.
The gas-phase reaction is carried out in a confined space by alkyl trichlorosilane and aqueous polymer coating. The polymer wrinkled surface is formed by diffusion and reaction of alkyl trichlorosilane, and the polymer is reacted by alkyl trichlorosilane with hydroxyl groups in the polymer to form a hydrophobic wrinkled structure.
It realizes controllable preparation of polymer wrinkled surfaces, can build superhydrophobic or adhesion surfaces, and has self-cleaning, anti-icing and titration-oriented conveying functions. It has simple process, low cost and controllable structure.
Smart Images
Figure CN117483205B_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a method for in-situ preparation of a polymer wrinkled surface, belonging to the technical field of organic polymer materials. Background Art
[0002] Surface wrinkles are a very common phenomenon in nature. For example, wrinkles on the surface of white blood cells, microscopic bristles on gecko toes, multi-level structures on lotus leaf surfaces, human fingerprints, and folded mountains. From the microscale to the macroscale, the wrinkled structure has been playing its unique role. Based on the bionics theory, researchers have begun to construct various wrinkled structures on the material surface to achieve specific properties.
[0003] The polymer wrinkled surface refers to the surface instability caused by the instability of the polymer itself and external stimuli, which further leads to the mismatch of internal stress in the polymer, thus forming a wrinkled pattern on the surface. The polymer wrinkled surface has wide application values in the fields of microfluidics, flexible electronic devices, sensors, manufacturing biological growth surfaces, constructing superhydrophobic surfaces, constructing adhesion surfaces, achieving self-cleaning, anti-icing, and drag reduction. At present, there are mainly three methods for preparing wrinkled surfaces: one is to initiate through mechanical stress and thermal stress, the second is to initiate through a bilayer structure, and the third is to form through gradient polymers generated by penetration. However, the current methods for preparing wrinkled surfaces have problems such as complex processes, high requirements for the substrate, difficulty in preparing coatings, poor reliability, and single surface structure. This severely limits the application of polymer wrinkled surfaces. Summary of the Invention
[0004] In view of this, the purpose of the present invention is to provide a method for in-situ preparation of a polymer wrinkled surface. The method has a simple process, no requirements for the substrate, controllable surface structure, and low cost.
[0005] To achieve the above purpose, the technical solution of the present invention is as follows.
[0006] A method for in-situ preparation of a polymer wrinkled surface, the method steps include:
[0007] Prepare an aqueous polymer coating on the surface of the substrate, the coating thickness is greater than or equal to 300 nm. Place the substrate and an open container filled with alkyltrichlorosilane in a closed reaction device respectively, with the surface of the aqueous polymer coating facing upwards. At 0 - 50 °C, the alkyltrichlorosilane volatilizes and reacts with the aqueous polymer coating to in-situ generate a polymer wrinkled surface; wherein, the structural general formula of the alkyltrichlorosilane is RSiCl3, R is an alkyl group, and the alkyltrichlorosilane is volatile at 0 - 50 °C.
[0008] Preferably, the aqueous polymer includes polyvinyl alcohol (PVA), aqueous polyurethane, or aqueous silicone resin.
[0009] Preferably, the substrate includes glass, metal, ceramic, organic matter, and carbon material.
[0010] Preferably, the method for preparing the aqueous polymer coating on the substrate surface includes brushing, spin coating, or dip coating.
[0011] Preferably, during brushing, an aqueous polymer solution or emulsion with a mass fraction of 1% - 30% is brushed on the substrate, and the brushing amount is greater than or equal to 20 μL / cm 2 , and after drying, an aqueous polymer coating is obtained on the substrate surface.
[0012] Preferably, during spin coating, an aqueous polymer solution or emulsion with a mass fraction of 1% - 30% is spin coated on the substrate, the spin coating speed is greater than or equal to 500 r / min, and after drying, an aqueous polymer coating is obtained on the substrate surface.
[0013] Preferably, the alkyltrichlorosilane includes one or more of methyltrichlorosilane, ethyltrichlorosilane, propyltrichlorosilane, butyltrichlorosilane, pentyltrichlorosilane, hexyltrichlorosilane, heptyltrichlorosilane, octyltrichlorosilane, nonyltrichlorosilane, decyltrichlorosilane, undecyltrichlorosilane, dodecyltrichlorosilane, tetradecyltrichlorosilane, hexadecyltrichlorosilane, octadecyltrichlorosilane, eicosyltrichlorosilane, triacontyltrichlorosilane, vinyltrichlorosilane, propenyltrichlorosilane, butenyltrichlorosilane, octenyltrichlorosilane, and undecenyltrichlorosilane.
[0014] Preferably, 0.005 mL or more of alkyltrichlorosilane is used per square centimeter of the polymer.
[0015] Preferably, 0 < relative humidity in the closed reaction device ≤ 80%.
[0016] Preferably, the contact reaction time is greater than or equal to 10 min.
[0017] Beneficial effects
[0018] (1) The present invention provides an in-situ preparation method for a polymer wrinkled surface. The polymer coating and alkyltrichlorosilane undergo a gas-phase reaction in a closed space. The alkyltrichlorosilane diffuses into the polymer coating, undergoes hydrolysis between the polymer crosslinking networks, and then self-polymerizes or reacts with the hydroxyl groups (-OH) in the polymer, resulting in the swelling of the polymer volume. Since there is a certain resistance to the diffusion of alkyltrichlorosilane into the polymer coating, the concentration of alkyltrichlorosilane diffusing into the deeper part of the polymer coating is lower. The alkyltrichlorosilane forms a concentration gradient in the longitudinal direction of the polymer coating, that is, the polymer generates a volume swelling gradient in the longitudinal direction, and then the surface becomes unstable and produces a wrinkled structure.
[0019] (2) The present invention provides an in-situ preparation method for a polymer wrinkled surface. Since alkyltrichlorosilane reacts with the hydrophilic hydroxyl groups (-OH) in the polymer coating and the alkyl groups have a low surface energy, the originally hydrophilic polymer coating becomes hydrophobic. Additionally, by controlling the wrinkled structure, a superhydrophobic surface with a "lotus effect" (lotus effect: refers to a lotus-like surface with a water contact angle greater than 150° and a rolling angle less than 10°) or an adhesive surface with a "rose petal effect" (rose petal effect: refers to a rose petal-like surface with a water contact angle greater than 150°, but the water droplets do not slide off after tilting) can be constructed, thereby realizing the functions of self-cleaning, anti-icing, and droplet directional transportation.
[0020] (3) The present invention provides an in-situ preparation method for a polymer wrinkled surface. The wrinkled surface is prepared by utilizing the principle that alkyltrichlorosilane can polymerize itself and react with aqueous polymers, and further controlling the coating thickness by controlling process parameters to control the size of the wrinkled structure. Specifically, the preparation method provided by the present invention has a simple process. After preparing the polymer coating, only a gas-phase reaction with alkyltrichlorosilane is required to obtain the wrinkled surface. The wrinkled surface prepared by the preparation method provided by the present invention has a controllable structure, and the controllable preparation of circular wrinkles, primary wrinkles, secondary wrinkles, and tertiary wrinkles can be achieved by controlling the coating thickness. The preparation method of the present invention is simple, effective, has a controllable structure, and is low in cost, and can realize the preparation of a polymer controllable wrinkled surface, greatly simplifying the preparation process of the polymer wrinkled surface. Description of the Drawings
[0021] Figure 1 Scanning electron microscope images of the polyvinyl alcohol circular wrinkles, primary wrinkles, secondary wrinkles, and tertiary wrinkles prepared in Example 1; (a) shows circular wrinkles, (b) shows primary wrinkles, (c) shows secondary wrinkles, and (d) shows tertiary wrinkles.
[0022] Figure 2 Scanning electron microscope images of the size-controllable polyvinyl alcohol wrinkles prepared in Example 2; (a) shows the wrinkles prepared at a spin-coating speed of 1000 r / min, (b) shows the wrinkles prepared at a spin-coating speed of 800 r / min, and (c) shows the wrinkles prepared at a spin-coating speed of 500 r / min.
[0023] Figure 3 Scanning electron microscope images of the size-controllable aqueous polyurethane wrinkles prepared in Example 3; (a) shows the wrinkles prepared with a brushing amount of 500 μL, and (b) shows the wrinkles prepared with a brushing amount of 1000 μL. Detailed Description of the Invention
[0024] The present invention will be further described in detail below with reference to specific examples.
[0025] An in-situ preparation method for a polymer wrinkled surface, comprising the following steps:
[0026] Coat an aqueous polymer solution / emulsion on a substrate, and obtain a polymer coating after drying;
[0027] Place the polymer coating and an open container filled with alkyltrichlorosilane in a closed reaction device for a gas-phase reaction, and an in-situ polymer wrinkled surface is generated after the reaction is completed.
[0028] In the present invention, the aqueous polymer solution / emulsion refers to a solution formed by a water-soluble polymer or an emulsion formed by a water-insoluble polymer in water, including polyvinyl alcohol (PVA) solution, aqueous polyurethane emulsion, aqueous silicone resin emulsion, etc. In the present invention, there is no limitation on the substrate material, including glass, metal, ceramic, organic matter, carbon material, etc. In the present invention, the drying method is not limited, including room temperature drying, heating drying, etc., and the drying temperature is based on the polymer not undergoing oxidative decomposition, preferably room temperature to 100 °C. In the present invention, the method for preparing the polymer coating is not limited, including brushing method, spin coating method, dip coating method, etc.
[0029] In the present invention, the alkyltrichlorosilane includes one or more of methyltrichlorosilane, ethyltrichlorosilane, propyltrichlorosilane, butyltrichlorosilane, pentyltrichlorosilane, hexyltrichlorosilane, heptyltrichlorosilane, octyltrichlorosilane, nonyltrichlorosilane, decyltrichlorosilane, undecyltrichlorosilane, dodecyltrichlorosilane, tetradecyltrichlorosilane, hexadecyltrichlorosilane, octadecyltrichlorosilane, eicosyltrichlorosilane, triacontyltrichlorosilane, vinyltrichlorosilane, propenyltrichlorosilane, butenyltrichlorosilane, octenyltrichlorosilane, undecenyltrichlorosilane, etc.
[0030] In the present invention, the specific operation of the gas-phase reaction is as follows: Place the polymer coating in a closed reaction vessel, and at the same time place a small beaker filled with alkyltrichlorosilane in the same closed reaction vessel. After the alkyltrichlorosilane volatilizes, hydrolyzes, and reacts with the polymer coating, a polymer wrinkled surface is obtained. The dosage of alkyltrichlorosilane can be determined according to the area of the polymer coating, and 0.005 mL or more of alkyltrichlorosilane is used per square centimeter of the polymer. The preferred range of the reaction conditions is a relative humidity of 0 to 80% and a temperature of 0 to 50 °C, and the reaction time is greater than or equal to 1 min. According to the volatility of the alkyltrichlorosilane, the temperature can be appropriately increased to ensure that the alkyltrichlorosilane can volatilize.
[0031] Example 1
[0032] In-situ prepare a controllable wrinkled surface of polyvinyl alcohol, and the method is as follows:
[0033] A 10% mass fraction polyvinyl alcohol solution was spin-coated onto a glass substrate (75×25 mm) at a speed of 7000 r / min; in addition, a 10% mass fraction polyvinyl alcohol solution was brush-coated onto a glass substrate (75×25 mm), and the brush-coated amounts were 500 μL, 1000 μL, and 1500 μL respectively. After drying, polyvinyl alcohol coatings were obtained on the substrates.
[0034] The polyvinyl alcohol coating and a beaker containing 2 mL of propyltrichlorosilane were respectively placed in a sealed reaction vessel with a relative humidity of 10%, and a gas-phase reaction was carried out for 5 h. After the reaction ended, a polyvinyl alcohol wrinkled surface was obtained.
[0035] Figure 1 is a scanning electron microscope image of the controllable polyvinyl alcohol wrinkled surface prepared in Example 1. Among them, (a) is an annular wrinkle prepared by the spin-coating method, and (b), (c), and (d) are primary wrinkles, secondary wrinkles, and tertiary wrinkles prepared with brush-coated amounts of 500 μL, 1000 μL, and 1500 μL respectively. Among them, the contact angles of the annular wrinkle, primary wrinkle, and secondary wrinkle are 150°, 152°, and 153° respectively, and the rolling angles are all greater than 90°, showing the "rose petal effect"; the contact angle of the tertiary wrinkle is 160°, and the rolling angle is 5°, showing the "lotus leaf effect". From Figure 1 It can be seen that Example 1 prepared a multi-level polyvinyl alcohol wrinkle with a controllable structure, indicating that the method provided by the present invention can effectively control the wrinkle structure.
[0036] Example 2
[0037] In-situ preparation of a controllable polyvinyl alcohol wrinkled surface, the method is as follows:
[0038] A 20% mass fraction polyvinyl alcohol solution was spin-coated onto a glass substrate (75×25 mm) at spin-coating speeds of 1000 r / min, 800 r / min, and 500 r / min respectively. After drying, polyvinyl alcohol coatings were obtained.
[0039] The polyvinyl alcohol coating and a beaker containing 1 mL of vinyltrichlorosilane were simultaneously placed in a sealed reaction vessel with a relative humidity of 20%, and a gas-phase reaction was carried out for 2 h. After the reaction ended, a polyvinyl alcohol wrinkled surface was obtained.
[0040] Figure 2 is a scanning electron microscope image of the controllable polyvinyl alcohol wrinkled surface prepared in Example 2. (a), (b), and (c) are wrinkles prepared at spin-coating speeds of 1000 r / min, 800 r / min, and 500 r / min respectively. Among them, the contact angles of (a), (b), and (c) are all greater than 150°, and the rolling angles are all greater than 90°, showing the "rose petal effect". From Figure 2It can be seen that in Example 2, polyvinyl alcohol wrinkles with controllable dimensions were prepared. As the spin-coating speed increased, the size of the wrinkles decreased, indicating that the method provided by the present invention can effectively control the wrinkle size.
[0041] Example 3
[0042] An in-situ preparation method for a waterborne polyurethane controllable wrinkle surface is as follows:
[0043] Brush a 10% mass fraction waterborne polyurethane emulsion onto a glass substrate (75×25 mm), and the brushing amounts are 500 μL and 1000 μL respectively. After drying, a waterborne polyurethane coating is obtained.
[0044] Place the waterborne polyurethane coating and a beaker containing 0.3 mL of propyltrichlorosilane in a closed reaction vessel simultaneously. The relative humidity is 50%, and a gas-phase reaction is carried out for 30 min. After the reaction, a waterborne polyurethane wrinkle surface is obtained.
[0045] Figure 3 is a scanning electron microscope image of the waterborne polyurethane wrinkle surface prepared in Example 3. (a) and (b) are the wrinkles prepared with brushing amounts of 500 μL and 1000 μL respectively. Among them, the contact angles of (a) and (b) are both greater than 150°, and the rolling angles are both greater than 90°, showing the "rose petal effect". It can be seen that Figure 3 in Example 3, waterborne polyurethane wrinkles with controllable dimensions were prepared. As the brushing amount increased, the size of the wrinkles increased, indicating that the method provided by the present invention can effectively control the wrinkle size.
[0046] In summary, the invention includes but is not limited to the above embodiments. Any equivalent replacement or partial improvement carried out under the spirit and principle of the present invention will be regarded as within the protection scope of the present invention.
Claims
1. An in-situ preparation method for a polymer wrinkled surface, characterized in that: The method steps include: Preparing an aqueous polymer coating on the surface of the substrate, with the coating thickness being greater than or equal to 300 nm. Place the substrate and an open container filled with alkyltrichlorosilane into a closed reaction device respectively, with the surface of the aqueous polymer coating facing upwards. At 0 - 50 °C, the alkyltrichlorosilane volatilizes and contacts the aqueous polymer coating to react in-situ to generate a polymer wrinkled surface; wherein, the structural general formula of the alkyltrichlorosilane is RSiCl3, R is an alkyl group, and the alkyltrichlorosilane is volatile at 0 - 50 °C. The methods for preparing an aqueous polymer coating on the surface of the substrate include brush coating, spin coating, or dip coating. When brushing, a water-based polymer solution or emulsion with a mass fraction of 10% - 30% is brushed on the substrate, and the brushing amount is greater than or equal to 20 μL / cm 2 . After drying, a water-based polymer coating is obtained on the surface of the substrate.
2. The in-situ preparation method of a polymer wrinkled surface according to claim 1, characterized in that: The aqueous polymer includes polyvinyl alcohol, aqueous polyurethane, or aqueous silicone resin.
3. The in-situ preparation method of a polymer wrinkled surface according to claim 1, characterized in that: The substrate includes glass, metal, ceramic, organic matter, carbon material.
4. The in-situ preparation method of a polymer wrinkled surface according to claim 1, wherein: During spin coating, spin coat an aqueous polymer solution or emulsion with a mass fraction of 10% - 30% on the substrate, with the spin coating speed being greater than or equal to 500 r / min. After drying, an aqueous polymer coating is obtained on the surface of the substrate.
5. The in-situ preparation method of a polymer wrinkled surface according to claim 1, characterized in that: The alkyltrichlorosilane includes one or more of methyltrichlorosilane, ethyltrichlorosilane, propyltrichlorosilane, butyltrichlorosilane, pentyltrichlorosilane, hexyltrichlorosilane, heptyltrichlorosilane, octyltrichlorosilane, nonyltrichlorosilane, decyltrichlorosilane, undecyltrichlorosilane, dodecyltrichlorosilane, tetradecyltrichlorosilane, hexadecyltrichlorosilane, octadecyltrichlorosilane, eicosyltrichlorosilane, triacontyltrichlorosilane, vinyltrichlorosilane, propenyltrichlorosilane, butenyltrichlorosilane, octenyltrichlorosilane, and undecenyltrichlorosilane.
6. The in-situ preparation method of a polymer wrinkled surface according to claim 1, characterized in that: Use more than 0.005 mL of alkyltrichlorosilane per square centimeter of the polymer.
7. A method for in-situ preparation of a polymer wrinkled surface according to any one of claims 1 to 6, characterized in that: 0 < relative humidity in the closed reaction device ≤ 80%.
8. A method for in-situ preparation of a polymer wrinkled surface according to any one of claims 1 to 6, characterized in that: The contact reaction time is greater than or equal to 10 min.