A fluorine-containing silicone resin modified matrix material and its preparation method and application

Abstract

The present invention provides a fluorine-containing silicone resin modified matrix material and a preparation method and application thereof. The method of the present invention comprises the steps of: dissolving trifluoropropyltrimethoxysilane in an organic solvent a, dripping an aqueous solution of an acid catalyst, and stirring evenly after the dripping is completed; standing for reaction, and then filtering, washing, and drying to obtain a fluorine-containing silicone resin; dissolving the fluorine-containing silicone resin and ethyl cyanoacrylate in an organic solvent b to obtain a coating modification liquid B; applying the coating modification liquid B on the surface of a substrate, and drying to obtain the obtained material. The present invention consumes less raw materials, and the preparation method is simple and easy, with low energy consumption and low cost; a variety of substrates can be subjected to performance optimization treatment; the modified material has good mechanical and chemical stability, which greatly improves the service life of the material, wherein the modified sponge has a great improvement in hydrophobicity, and has potential applications in the fields of oil-water separation or water pollution resistance.

Description

Technical Field

[0001] The invention relates to a fluorine-containing organic silicon resin modified matrix material and a preparation method and application thereof, belonging to the technical field of material surface modification. Background Art

[0002] The structure of silicone resin contains both "organic groups" and "inorganic structures". This special composition and molecular structure make it a combination of organic properties and inorganic functions. For example, low-temperature toughness, heat resistance, weather resistance, electrical insulation, hydrophobicity, flame retardancy, chemical resistance, etc. It has been widely used in aerospace, construction, defense industry and other fields. Due to the excellent performance of silicone resin, it is an ideal material for preparing various types of protective coatings. As we all know, fluorine-containing compounds are a type of low-surface energy material, which is related to the low surface energy of fluorine atoms. At present, many surface hydrophobic materials and self-cleaning materials are obtained by surface modification of organic fluorine substances. By modifying the material with fluorine and silicon elements, the chemical stability of C-F bonds and Si-O bonds can be used to improve the protective ability of the coating while retaining the excellent performance of the material; on the other hand, the surface tension of the coating can be reduced by introducing hydrophobic groups to improve the anti-penetration ability of the coating. Therefore, the synthesis of fluorine-containing silicone resin can combine the advantages of both fluorine and silicon elements, and has lower surface energy, more outstanding weather resistance and chemical stability than a single element, and can better achieve the required high-performance modified materials; it can be evenly dispersed in the matrix at the molecular level, giving the modified material better performance, and well solving the problems that traditional inorganic nanoparticle-modified polymers cannot solve.

[0003] Since the development of modern industry, the economy and technology have been increasingly prosperous worldwide, and oil, as the blood of industry, has also prospered. However, the oil leakage and discharge problems generated during the extraction, transportation and processing of oil have become increasingly serious. The increasing number of ship oil spills and marine oil spills have not only caused huge economic losses, but also seriously damaged the marine ecology. In addition, the leakage and discharge of water-insoluble chemical organic solvents in people's daily production have not only polluted water sources and soil, but also affected the activities of many organisms. In severe cases, they have also led to the death of a large number of organisms and the enrichment of toxic substances in the post-pollution environment, which has further burdened the environment and caused a vicious cycle. At present, there are physical methods (combustion method, gravity separation method, membrane separation method and adsorption method), chemical methods (chemical separation and oxidation method) and biological methods (biofilm method and activated sludge method) for the treatment of wastewater containing oil and organic solvents, but these methods have the defects of low oil-water separation efficiency, complex process and high operating cost; therefore, special wettability superhydrophobic materials with the advantages of good oil-water selectivity, simple operation and recyclability show broad application prospects.

[0004] Compared with natural absorbent materials, high-porosity sponges have great advantages due to their high absorption capacity, excellent compressibility and elasticity, and are easy to recycle, making sponges one of the best candidate materials for oil-water separation. However, these sponges are naturally hydrophilic, and they can absorb oil and water during the oil purification process, which reduces their separation efficiency and hinders the practical application of oil-water separation. Therefore, the preparation of a sponge material with high hydrophobicity and oleophilicity is of great significance to solving the problem of oil-water separation. At present, the preparation and performance research of superhydrophobic sponges mainly uses dopamine, vermiculite, Fe3O4 nanoparticles or reduced graphene oxide to form a rough structure on the surface of the substrate, and then uses different types of low surface energy substances to modify the material to obtain a superhydrophobic sponge. For example, a super hydrophobic and oleophilic sponge is prepared by modifying polyurethane sponge with low surface energy polysiloxane (PDMS) and nano-SiO2, which is used for separation of oil-water mixture and has good recycling performance; a super hydrophobic and flame-retardant sponge is prepared by modifying sponge with reduced graphene oxide (RGO), dopamine hydrochloride (DPA) and tridecafluorooctyl triethoxysiloxane (FAS), which greatly improves its hydrophobicity, thermal stability and exhibits good flame retardant effect. However, the preparation methods of these modified sponge materials require a large number of raw materials, which are costly, and the preparation methods are relatively complicated, with a long production cycle and high energy consumption; at the same time, the mechanical and chemical stability, service life, and hydrophobicity of the obtained materials need to be further improved.

[0005] Therefore, there is an urgent need to develop a modified matrix material with simple preparation method, low cost, good stability, long service life and excellent hydrophobic performance. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a fluorine-containing silicone resin modified matrix material and a preparation method and application thereof. The present invention uses a synthetic fluorine-containing silicone resin to modify the surface of the original sponge, which consumes less raw materials, and the preparation method is simple and easy, with low energy consumption and low cost; and this fluorine-containing silicone resin can also be used to optimize the performance of various other substrates; the modified material has good mechanical and chemical stability, which greatly improves the service life of the material, and the modified sponge has a great improvement in hydrophobic performance, and has potential applications in the fields of oil-water separation or water pollution resistance. The present invention can realize the large-scale preparation of super-hydrophobic materials, so that they can be widely used.

[0007] The technical solution of the present invention is as follows:

[0008] A fluorine-containing organosilicon resin modified matrix material, the material comprising: a matrix surface coated with a fluorine-containing organosilicon resin / ethyl cyanoacrylate mixed material modified layer; the fluorine-containing organosilicon resin is obtained by hydrolysis and polycondensation of trifluoropropyltrimethoxysilane.

[0009] Preferably according to the present invention, the substrate is a sponge.

[0010] Preferably according to the present invention, the thickness of the modified layer of the fluorine-containing silicone resin / ethyl cyanoacrylate mixed material is 100-1000 nm.

[0011] The method for preparing the above-mentioned fluorine-containing silicone resin modified matrix material comprises the steps of:

[0012] (1) dissolving trifluoropropyltrimethoxysilane in an organic solvent a, adding dropwise an aqueous solution of an acid catalyst, and stirring evenly after the addition is complete to obtain a solution A; allowing the solution to react, and then filtering, washing, and drying to obtain a fluorine-containing organosilicon resin;

[0013] (2) dissolving the fluorinated silicone resin and ethyl cyanoacrylate (ECA) obtained in step (1) in an organic solvent b to obtain a coating modification liquid B; applying the coating modification liquid B on the surface of the substrate, and drying to obtain a fluorinated silicone resin modified matrix material.

[0014] Preferably, according to the present invention, in step (1), the organic solvent a is methanol, ethanol, propanol, acetone or tetrahydrofuran, preferably methanol; the volume ratio of trifluoropropyltrimethoxysilane to organic solvent a is 1-1.5:10-15, preferably 1:13.

[0015] According to the preferred embodiment of the present invention, in step (1), the acid catalyst is hydrochloric acid, sulfuric acid or nitric acid, preferably hydrochloric acid; the mass concentration of the aqueous solution of the acid catalyst is 10-50%; the volume ratio of trifluoropropyltrimethoxysilane to the aqueous solution of the acid catalyst is 1-1.5:1.5-1, preferably 1:1.2. Using a strong acid as a catalyst can accelerate the hydrolysis and polycondensation reaction process and promote the formation of the fluorine-containing silicone resin structure.

[0016] Preferably, according to the present invention, in step (1), the static reaction temperature is 15-30° C., and the static reaction time is 7-30 days; preferably, the static reaction time is 10-15 days.

[0017] Preferably according to the present invention, in step (2), the organic solvent b is dichloromethane, chloroform or tetrahydrofuran, preferably dichloromethane; and the mass ratio of ethyl cyanoacrylate to the volume ratio of organic solvent b is 0.01-0.02 g / ml.

[0018] Preferably, in step (2), the mass ratio of the fluorinated silicone resin to ethyl cyanoacrylate is 1:9-99. The biocompatible adhesive, ethyl cyanoacrylate (ECA), is an organic compound with the structural formula CH2=C(CN)COOC2H5. It rapidly polymerizes and solidifies under the action of water vapor at room temperature, has extremely strong adhesiveness, and has extremely strong mechanical stability.

[0019] Preferably, according to the present invention, in step (2), the coating method is spraying or immersion; preferably, when the coating method is spraying, the amount of coating modification liquid B required per square centimeter of substrate surface is 0.1-1 mL.

[0020] According to the preferred embodiment of the present invention, in step (2), the drying temperature is 20-50°C, and the drying time is 10-60 min; preferably, the drying temperature is 30-40°C, and the drying time is 20-30 min.

[0021] The above-mentioned fluorine-containing silicone resin modified matrix material is used as a hydrophobic material for water pollution resistance or oil-water separation.

[0022] The technical features and beneficial effects of the present invention are as follows:

[0023] 1. The present invention synthesizes a novel fluorinated organosilicon resin (FSI) in a simple one-step manner through the hydrolysis and condensation of trifluoropropyltrimethoxysilane, enriches the fluorinated structural materials used for substrate surface modification, and then utilizes the self-assembly properties of organosilicon resin nanoparticles to form different micro- and nano-level structures on the surface of the substrate material, thereby obtaining an ideal liquid repellent effect to increase the hydrophobicity of the material. The novel fluorinated organosilicon resin modified liquid is coated on the sponge and other substrates by spraying or infiltration. After the solvent evaporates and ethyl cyanoacrylate polymerizes, the polymerized ECA in the coating material firmly adheres the novel fluorinated organosilicon resin to the substrate surface in a physical blending manner, and the rigid polyECA and the novel fluorinated organosilicon resin with low surface energy and stable structure play a synergistic role together to give the material strong chemical stability and mechanical stability, so that it exhibits excellent performance in terms of wear resistance, peeling resistance, high temperature resistance, and acid, alkali and salt resistance, and prolongs the service life of the material. In particular, the modified sponge greatly improves the hydrophobicity and shows great application potential in the fields of oil-water separation and water pollution resistance.

[0024] 2. In the present invention, the silicon element, which has a low surface energy, forms a silicon-oxygen bond with oxygen with a low surface tension, and has a certain hydrophobic property. Then, the new fluorine-containing silicone resin formed after the introduction of the fluorine element with a lower surface energy greatly enhances the hydrophobic effect of the modified material. When the modified liquid is applied to the substrate, the new fluorine-containing silicone resin will automatically migrate to the surface of the coating, and combined with the polymerized ECA, the coating surface shows a low surface energy, achieving the maximum hydrophobic effect. The hydrophobic effect of the material comes from the hydrophobicity of the modified substrate surface molecules themselves on the one hand, and from the roughness constructed by the micro-nano structuring of the fluorine-containing silicone resin nanoparticles on the substrate surface on the other hand, which is similar to the microstructure of the lotus leaf surface. The modified sponge prevents water droplets from wetting while ensuring the smooth passage of oil droplets. It has good hydrophobicity and lipophilicity, and the water contact angle can reach more than 150°. It has super hydrophobic properties and is effective in resisting aqueous liquids.

[0025] 3. The preparation method of the present invention is simple and easy, requires less raw materials that are cheap and easy to obtain, does not require energy loss such as high temperature and low temperature during the synthesis process, can also react at room temperature, has low preparation cost, can achieve large-scale preparation of super-hydrophobic materials, so that it can be promoted and applied; and the preparation process is green and pollution-free.

[0026] 4. The preparation method and various conditions of the present invention are a whole, and only when they work together can the excellent effects of the present invention be achieved. If the conditions are not appropriate, such as the concentration of ethyl cyanoacrylate in the coating modification liquid, the mass ratio of the fluorinated silicone resin and ethyl cyanoacrylate, the coating degree, etc., the excellent effects of the present invention cannot be achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is the Fourier transform infrared (FTIR) spectrum of the fluorine-containing silicone resin prepared in Example 1 of the present invention; wherein the abscissa is the wavelength.

[0028] Figure 2 This is the XPS measurement spectrum of the fluorine-containing silicone resin prepared in Example 1 of the present invention; wherein the abscissa is the binding energy and the ordinate is the intensity.

[0029] Figure 3 It is the Fourier transform infrared (FTIR) spectra of the original PU sponge, the PU-ECA prepared in Comparative Example 1, and the PU-ECA-FSI prepared in Example 3; wherein the abscissa is the wavelength.

[0030] Figure 4 These are SEM images of original PU sponge (a1, a2) and PU-ECA-FSI (b1, b2) prepared in Example 3 at different magnifications.

[0031] Figure 5It is the XPS measurement spectrum of the original PU sponge and the PU-ECA-FSI prepared in Example 3; wherein the abscissa is the binding energy and the ordinate is the intensity.

[0032] Figure 6 Graph showing the change in water contact angle of the modified sponge prepared in Example 3 after tape stripping cycles.

[0033] Figure 7 This is a graph showing the change in water contact angle of the modified sponge prepared in Example 3 within a certain temperature range.

[0034] Figure 8 This is a graph showing the change in water contact angle of the modified sponge prepared in Example 3 after ultrasonic washing for different periods of time.

[0035] Fig. 9 This is a graph showing the change in water contact angle of the modified sponge prepared in Example 3 after being soaked in acid, alkali or salt for different periods of time.

[0036] Fig.10 This is a graph showing the adsorption of different types of oils by the modified sponge and the original sponge prepared in Example 3. DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with specific experimental examples and drawings, but is not limited thereto.

[0038] Meanwhile, the methods described in the following embodiments, unless otherwise specified, are conventional methods; the materials described, unless otherwise specified, can be obtained from commercial channels.

[0039] Example 1

[0040] The synthesis steps of a fluorine-containing silicone resin are as follows:

[0041] 20 ml of trifluoropropyltrimethoxysilane was added dropwise to 260 ml of methanol solvent at room temperature of 20-30°C, and stirred while adding dropwise, and then 24 ml of hydrochloric acid aqueous solution (mass fraction 37%) was added dropwise as an acid catalyst, and after stirring evenly, the mixture was sealed and allowed to stand at 20-30°C for 14 days, and a large amount of white solid precipitates were generated in the solution. The reaction mixture was filtered to obtain a white solid, which was washed with fresh methanol solvent and vacuum dried to obtain a white precipitate product, namely, a fluorine-containing silicone resin.

[0042] Characterization of the product: Figure 1 and Figure 2 The Fourier transform infrared (FTIR) spectrum and XPS measurement spectrum of the prepared fluorinated silicone resin are shown respectively. -1 There is a strong and sharp absorption peak, which corresponds to the absorption vibration peak of the Si-O-Si structure formed, and 1217cm -1 、1264cm-1 The absorption peak at comes from CF in the trifluoropropyl group; the surface composition of the prepared solid was further analyzed by XPS, and 102.1eV and 154.3eV represented the Si element, and the binding energies of 289.2eV, 532.8eV, and 688.0eV showed the peaks of C1s, O 1s, and F 1s, respectively.

[0043] Example 2

[0044] A method for preparing a fluorine-containing organic silicone resin modified sponge material comprises the steps of:

[0045] The fluorinated silicone resin and ethyl cyanoacrylate synthesized by the method of Example 1 were dissolved in dichloromethane to obtain a mixed solution; the volume ratio of ethyl cyanoacrylate to dichloromethane in the mixed solution was 0.013 g / ml, and the mass ratio of fluorinated silicone resin to ethyl cyanoacrylate was 1:99; the mixed solution was sprayed on a sponge substrate (polyurethane sponge, i.e., original PU sponge) 12 times (each spraying was to spray the surface of the sponge substrate evenly and completely) (each square centimeter of the sponge surface needed to be sprayed with about 0.05 mL of the spraying liquid, and the sprayed modified layer existed on the sponge surface or the outer layer), and then ventilated and dried at room temperature for 30 minutes to obtain a fluorinated silicone resin modified sponge material (FSI (1%) / ECA-PU).

[0046] Example 3

[0047] A method for preparing a fluorine-containing organic silicone resin modified sponge material comprises the steps of:

[0048] The fluorinated silicone resin and ethyl cyanoacrylate synthesized by the method of Example 1 were dissolved in dichloromethane to obtain a mixed solution; the volume ratio of ethyl cyanoacrylate to dichloromethane in the mixed solution was 0.013 g / ml, and the mass ratio of fluorinated silicone resin to ethyl cyanoacrylate was 3:97; the mixed solution was sprayed on a sponge substrate (polyurethane sponge, i.e., original PU sponge) 12 times (each spraying was to spray the surface of the sponge substrate evenly and completely) (each square centimeter of the sponge surface needed to be sprayed with about 0.05 mL of spraying liquid each time, and the sprayed modified layer existed on the sponge surface or the outer layer), and then ventilated and dried at room temperature for 30 minutes to obtain a fluorinated silicone resin modified sponge material (FSI (3%) / ECA-PU).

[0049] Example 4

[0050] A method for preparing a fluorine-containing organic silicone resin modified sponge material comprises the steps of:

[0051] The fluorinated silicone resin and ethyl cyanoacrylate synthesized by the method of Example 1 were dissolved in dichloromethane to obtain a mixed solution; the volume ratio of ethyl cyanoacrylate to dichloromethane in the mixed solution was 0.013 g / ml, and the mass ratio of fluorinated silicone resin to ethyl cyanoacrylate was 5:95; the mixed solution was sprayed on a sponge substrate (polyurethane sponge, i.e., original PU sponge) 12 times (each spraying was to spray the surface of the sponge substrate evenly and completely) (each time about 0.05 mL of spraying liquid was sprayed on each square centimeter of the sponge surface, and the sprayed modified layer existed on the sponge surface or the outer layer), and then ventilated and dried at room temperature for 30 minutes to obtain a fluorinated silicone resin modified sponge material (FSI (5%) / ECA-PU).

[0052] Example 5

[0053] A method for preparing a fluorine-containing organic silicone resin modified sponge material comprises the steps of:

[0054] The fluorinated silicone resin and ethyl cyanoacrylate synthesized by the method of Example 1 were dissolved in dichloromethane to obtain a mixed solution; the volume ratio of ethyl cyanoacrylate to dichloromethane in the mixed solution was 0.013 g / ml, and the mass ratio of fluorinated silicone resin to ethyl cyanoacrylate was 7:93; the mixed solution was sprayed on a sponge substrate (polyurethane sponge, i.e., original PU sponge) 12 times (each spraying was to spray the surface of the sponge substrate evenly and completely) (each time about 0.05 mL of spraying liquid was sprayed on each square centimeter of the sponge surface, and the sprayed modified layer existed on the sponge surface or the outer layer), and then ventilated and dried at room temperature for 30 minutes to obtain a fluorinated silicone resin modified sponge material (FSI (7%) / ECA-PU).

[0055] Example 6

[0056] A method for preparing a fluorine-containing organic silicone resin modified sponge material comprises the steps of:

[0057] The fluorinated silicone resin and ethyl cyanoacrylate synthesized by the method of Example 1 were dissolved in dichloromethane to obtain a mixed solution; the volume ratio of ethyl cyanoacrylate to dichloromethane in the mixed solution was 0.013 g / ml, and the mass ratio of fluorinated silicone resin to ethyl cyanoacrylate was 10:90; the mixed solution was sprayed on a sponge substrate (polyurethane sponge, i.e., original PU sponge) 12 times (each spraying was to spray the surface of the sponge substrate evenly and completely) (each time about 0.05 mL of spraying liquid was sprayed on each square centimeter of the sponge surface, and the sprayed modified layer existed on the sponge surface or the outer layer), and then ventilated and dried at room temperature for 30 minutes to obtain a fluorinated silicone resin modified sponge material (FSI (10%) / ECA-PU).

[0058] Comparative Example 1

[0059] The preparation steps of a modified sponge material are as follows: dissolving ethyl cyanoacrylate in dichloromethane to obtain a mixed solution; the mass ratio of ethyl cyanoacrylate to dichloromethane in the mixed solution is 0.013 g / ml; spraying the mixed solution on a sponge substrate 12 times (each spraying is to spray the surface of the sponge substrate evenly and completely) (each square centimeter of the sponge surface needs to be sprayed with about 0.05 mL of the spraying liquid each time, and the sprayed modified layer exists on the sponge surface or the outer layer), and then drying under ventilation at room temperature for 30 minutes to obtain a modified sponge material (FSI (0%) / ECA-PU).

[0060] Test Example 1

[0061] 1. Contact angle test: The modified sponge materials obtained in Examples 2-6 and Comparative Example 1 were tested for water contact angle using a DSA25 contact angle meter (KRUSS, Germany). The water contact angle test data are listed in Table 1 (the water contact angle test was performed by selecting three points on the material surface and performing three tests on each point).

[0062] Table 1

[0063] Modified sponge Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Water contact angle / ° 139.6±2.3 155.1±1.9 143.9±0.7 147.5±2.8 149.3±1.7 136.7±1.8

[0064] As can be seen from Table 1, the water contact angle of the modified sponge introduced with ethyl cyanoacrylate increases from about 90° of the original sponge to about 137°. This is because the surface of the original sponge is coated with ethyl cyanoacrylate after polymerization, and the molecules on the surface of the sponge contain a large number of hydrophobic groups composed of carbon-nitrogen triple bonds and ester groups with very weak polarity, which significantly improves the water contact angle of the material; and the contact angle of the modified sponge further infiltrated with a trace amount of the new fluorinated silicone resin is stably higher than 140°, and the water contact angle of the sponge prepared in Example 3 can reach more than 150°, achieving a super-hydrophobic effect. This is because the introduction of the new fluorinated silicone resin significantly reduces the surface energy of the material. On the one hand, it is the hydrophobicity of the surface molecules of the modified substrate themselves, and on the other hand, it is the roughness of the micro-nano structure constructed by the new fluorinated silicone resin.

[0065] 2. The original PU sponge, the modified sponge (PU-ECA-FSI) obtained in Example 3 and the modified sponge (PU-ECA) prepared in Comparative Example 1 were compared, and the surface of the sponge was characterized by Fourier transform infrared (FTIR) spectroscopy, field emission scanning electron microscopy (SEM) and in situ X-ray photoelectron spectroscopy (XPS). The results are shown in Figure 3 , Figure 4 and Figure 5 .

[0066] Figure 3 As can be seen, for the original PU sponge, at 1103cm -1 The strong absorption peak at 1757 cm is derived from the asymmetric stretching vibration of a large amount of COC in the PU sponge. For the sponge coated with only ethyl cyanoacrylate (PU-ECA), the ester wrapped the original sponge, and the infrared absorption peak at 1757 cm -1 The C=O peak at 1105 cm represents the ethyl cyanoacrylate wrapped in the sponge, while the modified sponge (PU-ECA-FSI) shows a peak at 1105 cm in the infrared. -1 The Si-O-Si peak and 1217cm -1 、1264cm -1 The CF peak at 1.37° confirmed the introduction of the prepared fluorinated silicone resin into the sponge. Figure 4 It can be seen that the modified sponge (PU-ECA-FSI) changed from the original smooth surface to a rough and greasy feeling, with some obvious depressions and some agglomerated particles attached, indicating that the fluorinated silicone resin has been successfully bonded to the sponge under the polymerization of ethyl cyanoacrylate; further XPS was used to perform surface chemical analysis of the original PU and PU-ECA-FSI sponges. Compared with the original PU, in addition to the C1s and O 1s peaks at 288.1eV and 531.8eV, the modified sponge (PU-ECA-FSI) significantly increased the F1s, N 1s, Si 2s, and Si 2p peaks at 688.1eV, 400.0eV, 152.9eV, and 103.0eV, respectively. The obvious increase in the N1s peak is due to the effect of ethyl cyanoacrylate, and the F and Si elements come from the prepared fluorinated silicone resin, which indicates that the prepared fluorinated silicone resin is successfully bonded to the surface of the sponge, achieving the goal of modifying the sponge.

[0067] Test Example 2

[0068] Exploration of process conditions: Exploration of the mass ratio of ethyl cyanoacrylate to dichloromethane solvent

[0069] The preparation method of the fluorinated silicone resin modified sponge material is as described in Example 3, except that the volume ratio of the mass of ethyl cyanoacrylate to dichloromethane in the mixed solution is changed to 0.010, 0.011, 0.012, 0.013, 0.014, 0.015, and 0.020 g / ml, respectively; the other steps and conditions are the same as those in Example 3.

[0070] The best volume ratio of ethyl cyanoacrylate to dichloromethane solvent was determined to be 0.013 g / ml based on the actual spraying effect of the spraying instrument and the maximum binder concentration.

[0071] Test Example 3

[0072] Exploration of process conditions: optimal spraying times

[0073] The preparation method of the fluorine-containing silicone resin modified sponge material is as described in Example 3, except that the number of spraying is changed to 6, 9, 15, and 18 times respectively; the other steps and conditions are consistent with Example 3.

[0074] The change in water contact angle determined that the optimal number of spraying times was 12 times, at which the water contact angle was the most stable. The water contact angle test data is listed in Table 2 (the water contact angle test was performed by selecting three points on the material surface and performing three tests on each point).

[0075] Table 2

[0076] Spraying times 6 9 12 15 18 Water contact angle / ° 144.5±1.4 152.1±1.0 155.1±1.9 154.4±1.7 155±2.8

[0077] Test Example 4

[0078] The physical stability (tape peeling, high temperature, ultrasonic washing), chemical stability (resistance to acid and alkali salt solutions) and anti-fouling effect of the modified sponge obtained by the method of Example 3 were investigated.

[0079] (1) Tape peeling test: The modified sponge surface was subjected to a tape peeling test using a commercially available tape. The tape was placed on the modified sponge surface and a 200 g weight was rolled on the tape once to ensure good contact between the sponge surface and the tape. After peeling off the tape, the water contact angle was remeasured (the water contact angle test was performed three times at the same point on the material surface). Figure 6 The change in water contact angle after 100 repeated tape peeling tests is shown. It can be seen that the modified sponge also exhibits high hydrophobicity after 100 cycles, indicating that the modified sponge has good peeling resistance stability.

[0080] (2) High temperature test: Place the modified sponge in a constant temperature environment at different temperatures of 30-150℃ for 1 hour, and test the water contact angle every 30℃ (the water contact angle test is performed three times at the same point on the material surface). Figure 7 As shown, it can be seen that below 120°C, the water contact angle of the modified sponge does not change much. At 150°C, the water contact angle decreases to a certain extent, but is still around 145°, indicating that the modified sponge has a certain high temperature stability.

[0081] (3) Ultrasonic washing test: The modified sponge was placed in an ultrasonic water bath for 60 minutes, and the water contact angle was tested every 15 minutes (the water contact angle test was performed three times at the same point on the material surface). The water washing resistance of the modified sponge was as follows: Figure 8As shown in the figure, the water contact angle after 60 minutes of ultrasonic cleaning showed no significant change compared with the initial water contact angle. This result indicates that the prepared modified sponge has a strong and stable superhydrophobic coating with excellent mechanical stability.

[0082] (4) Acid and alkali salt solution test: The modified sponge was immersed in a hydrochloric acid aqueous solution with a pH of 2, a sodium chloride aqueous solution with a pH of 7 (mass concentration of 3.5%), or a sodium hydroxide aqueous solution with a pH of 12, and the change in water contact angle within 48 hours in different solutions was measured (the water contact angle test of the same solution at different times was obtained by testing the same point on the material surface three times). Fig. 9 (a: hydrochloric acid solution with pH=2; b: 3.5% sodium chloride solution; c: sodium hydroxide solution with pH=12) As shown in the figure, the water contact angle of the modified sponge immersed in acidic solution and alkaline solution did not change much, and it decreased significantly after one day in the salt solution, but the contact angle was still above 140° and remained stable. This shows that the modified sponge has good chemical stability against acids, alkalis and salts.

[0083] (5) Anti-fouling test: Since the modified sponge has good resistance to aqueous liquids, it has potential application value in anti-water staining. The fluorinated silicone resin modified sponge prepared in Example 3 and the original sponge were completely immersed in water at room temperature for one minute for water adsorption test. The water adsorption of the original sponge can reach 6.5-8g / g, but the water adsorption of the modified sponge is only in the range of 0-0.1g / g, and an obvious bright air layer can be observed in the water, which prevents the sponge from being wetted by water. It can be concluded that the modified sponge has good anti-water staining ability.

[0084] Test Example 5

[0085] Oil adsorption experiment: In order to analyze the oil adsorption performance, the fluorinated silicone resin modified sponge prepared in Example 3 and the original sponge were weighed (m0) respectively, and then immersed in a watch glass filled with different oils for observation. After the oil was adsorbed for a certain period of time and saturated, the sponge was taken out and weighed (m f The adsorption amount of oil Q (g / g) is determined according to the following equation: Q = (m f -m0) / m0

[0086] Where Q is the adsorption capacity of the material (g / g). m0 is the mass of the material before adsorption (g). f is the mass of the material after oil adsorption (g).

[0087] like Fig.10As shown in the figure, the adsorption amount of different types of oil (petroleum ether, n-hexane, isopropanol, toluene, dichloromethane, chloroform) by the fluorinated silicone resin modified sponge prepared in Example 3. Since a sponge of a certain mass has a certain pore structure and the volume of liquid it can accommodate is limited, the adsorption amount of the sponge increases with the increase of the density of the adsorbed solvent. Chloroform has the highest density, which is 1.48 g / cm 3 Therefore, the sponge has the highest adsorption capacity for chloroform, nearly 60g / g. Compared with the original sponge, the modified sponge has a reduced oil adsorption capacity compared with the original sponge at the same volume, mainly due to the coating of ethyl cyanoacrylate on the sponge, which reduces the pore volume of the original sponge to a certain extent. However, the reduction is only about 1%. Compared with its greatly improved hydrophobic performance, the modified sponge has great application value in treating oil and water pollution.

Claims

1. A fluorine-containing silicone resin modified matrix material, characterized in that: The material is: a substrate surface is coated with a modified layer of a fluorinated organic silicone resin / ethyl cyanoacrylate mixed material; the fluorinated organic silicone resin is obtained by hydrolysis and polycondensation of trifluoropropyltrimethoxysilane; The substrate is a sponge; The method for preparing the fluorine-containing organic silicon resin modified matrix material comprises the steps of: (1) dissolving trifluoropropyltrimethoxysilane in an organic solvent a, adding dropwise an aqueous solution of an acid catalyst, and stirring evenly after the addition is complete to obtain a solution A; allowing the solution to react, and then filtering, washing, and drying to obtain a fluorine-containing organosilicon resin; (2) dissolving the fluorinated organosilicon resin and ethyl cyanoacrylate (ECA) obtained in step (1) in an organic solvent b to obtain a coating modification liquid B; applying the coating modification liquid B on the surface of the substrate, and drying to obtain a fluorinated organosilicon resin modified matrix material; The mass ratio of the fluorine-containing silicone resin to ethyl cyanoacrylate is 3:97-10:

90.

2. The fluorine-containing silicone resin modified matrix material according to claim 1, characterized in that: The thickness of the modified layer of the fluorine-containing organic silicone resin / ethyl cyanoacrylate mixed material is 100-1000nm.

3. The method for preparing a fluorine-containing silicone resin modified matrix material according to claim 1, characterized in that: In step (1), the organic solvent a is methanol, ethanol, propanol, acetone or tetrahydrofuran; and the volume ratio of trifluoropropyltrimethoxysilane to the organic solvent a is 1-1.5:10-15.

4. The method for preparing a fluorinated silicone resin modified matrix material according to claim 1, characterized in that: In step (1), the acid catalyst is hydrochloric acid, sulfuric acid or nitric acid; the mass concentration of the aqueous solution of the acid catalyst is 10-50%; the volume ratio of trifluoropropyltrimethoxysilane to the aqueous solution of the acid catalyst is 1-1.5:1.5-1.

5. The method for preparing a fluorine-containing silicone resin modified matrix material according to claim 1, characterized in that: In step (1), the static reaction temperature is 15-30° C., and the static reaction time is 7-30 days.

6. The method for preparing a fluorine-containing silicone resin modified matrix material according to claim 1, characterized in that: In step (2), the organic solvent b is dichloromethane, chloroform or tetrahydrofuran; and the mass ratio of ethyl cyanoacrylate to the organic solvent b is 0.01-0.02 g / ml.

7. The method for preparing a fluorine-containing silicone resin modified matrix material according to claim 1, characterized in that: In step (2), the coating method is spraying or dipping.

8. The method for preparing a fluorine-containing silicone resin modified matrix material according to claim 7, characterized in that: When the coating method is spray coating, the amount of coating modification liquid B required per square centimeter of substrate surface is 0.1-1 mL.

9. Use of the fluorine-containing silicone resin modified matrix material as claimed in any one of claims 1 to 8 as a hydrophobic material for water pollution resistance or oil-water separation.

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