Preparation method of stable perfluorohexyl functionalized active POSS (polyhedral oligomeric silsesquioxane) -based super-amphiphobic coating modified cotton fabric
阅读说明：本技术 一种稳定的全氟己基功能化活性poss基超双疏涂层改性棉织物的制备方法 (Preparation method of stable perfluorohexyl functionalized active POSS (polyhedral oligomeric silsesquioxane) -based super-amphiphobic coating modified cotton fabric ) 是由 刘鸿志 李万里 于 2021-10-18 设计创作，主要内容包括：本发明提供了一种稳定的全氟己基功能化活性POSS基超双疏涂层改性棉织物的制备方法,包括步骤：将八巯丙基笼型倍半硅氧烷、全氟己基乙烯和乙烯基硅烷加入溶剂中,之后加入光引发剂,混合均匀后,进行光催化反应,得到全氟己基POSS溶液；将棉织物浸泡在得到的全氟己基POSS溶液中,之后将浸泡后的棉织物在碱性环境下进行水解,经干燥,得到稳定的全氟己基功能化活性POSS纳米粒子基超双疏涂层改性棉织物。本发明的制备方法步骤简单,条件温和,得到的改性棉织物具有良好的抗拒液体的能力,在自清洁和防污方面有着潜在的应用价值。(The invention provides a preparation method of a stable perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric, which comprises the following steps: adding octamercaptopropyl polyhedral oligomeric silsesquioxane, perfluorohexylethylene and vinyl silane into a solvent, then adding a photoinitiator, uniformly mixing, and carrying out a photocatalytic reaction to obtain a perfluorohexylPOSS solution; soaking a cotton fabric in the obtained perfluorohexyl POSS solution, then hydrolyzing the soaked cotton fabric in an alkaline environment, and drying to obtain the stable perfluorohexyl functionalized active POSS nanoparticle-based super-amphiphobic coating modified cotton fabric. The preparation method disclosed by the invention is simple in steps and mild in conditions, and the obtained modified cotton fabric has good liquid resistance and has potential application values in self-cleaning and anti-fouling aspects.)
1. A preparation method of a stable perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric comprises the following steps:
(1) adding octamercaptopropyl polyhedral oligomeric silsesquioxane, perfluorohexylethylene and vinyl silane into a solvent, then adding a photoinitiator, uniformly mixing, and carrying out a photocatalytic reaction to obtain a perfluorohexylPOSS solution;
(2) soaking a cotton fabric in the perfluorohexyl POSS solution obtained in the step (1), hydrolyzing the soaked cotton fabric in an alkaline environment, and drying to obtain the stable perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric.
2. The method for preparing the super-amphiphobic coating modified cotton fabric according to claim 1, wherein the vinyl silane in the step (1) is trimethoxy vinyl silane or triethoxy vinyl silane.
3. The preparation method of the super-amphiphobic coating modified cotton fabric according to claim 1, wherein the ratio of the mole number of the octamercaptopropyl cage-type silsesquioxane in the step (1) to the total mole number of the perfluorohexylethylene and the vinyl silane is 1: 8; the molar ratio of perfluorohexylethylene to vinylsilane is 1-7:7-1, preferably 1:7, 2:6, 3:5, 4:4, 5:3, 6:2 or 7:1, and more preferably 7: 1.
4. The method for preparing the super-amphiphobic coating modified cotton fabric according to the claim 1, wherein the solvent in the step (1) is tetrahydrofuran, diethyl ether, dichloromethane, chloroform, o-dichlorobenzene, 1, 2-dichloroethane, N-dimethylformamide or dimethyl sulfoxide, and is preferably tetrahydrofuran.
5. The method for preparing the super-amphiphobic coating modified cotton fabric according to the claim 1, wherein the photoinitiator in the step (1) is 2, 2-dimethoxy-2-phenylacetophenone, 2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexyl phenyl ketone, ethyl 4-dimethylaminobenzoate, benzophenone, 4-chlorobenzophenone, 4-methylbenzophenone or methyl o-benzoylbenzoate; the addition amount of the photoinitiator is 0.1-5 wt% of the mass of the octamercaptopropyl cage-type silsesquioxane.
6. The preparation method of the super-amphiphobic coating modified cotton fabric according to the claim 1, wherein the photocatalytic reaction time in the step (1) is 10-120 minutes, preferably 40-60 minutes; the light source of the light for the photocatalytic reaction is a 100W ultraviolet lamp, and the wavelength is 10-400 nm.
7. The preparation method of the super-amphiphobic coating modified cotton fabric as claimed in claim 1, wherein the concentration of the perfluorohexyl POSS in the perfluorohexyl POSS solution in the step (1) is 10-110mg/mL, preferably 50-90 mg/mL.
8. The method for preparing the super-amphiphobic coating modified cotton fabric according to the claim 1, wherein the soaking time in the step (2) is 1-24 hours, preferably 4-10 hours.
9. The preparation method of the super-amphiphobic coating modified cotton fabric according to the claim 1, wherein the alkaline environment in the step (2) is in an ammonia atmosphere, and the hydrolysis time is 10-120 min; the hydrolysis step specifically comprises: and under a closed condition, placing the soaked cotton fabric above ammonia water, and hydrolyzing under the atmosphere of ammonia gas provided by ammonia water volatilization, wherein the temperature of the ammonia water is 20-90 ℃, the further optimization is 40-45 ℃, and the concentration of the ammonia water is 25-28 wt%.
10. The preparation method of the super-amphiphobic coating modified cotton fabric according to the claim 1, wherein the drying temperature in the step (2) is 30-100 ℃, preferably 50-60 ℃; the drying time is 0.5-5h, preferably 1 h.
Technical Field
The invention relates to a preparation method of a stable perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric, belonging to the technical field of organic silicon fabric surface modification.
Background
Polyhedral Oligomeric Polyhedral silsesquioxane (POSS) has good chemical stability and thermal stability and low specific surface energy and is multifunctionalThe compound has potential application prospects in the aspects of water treatment, catalysis, chemical sensors and the like. The space structure of POSS molecules is very regular, and the POSS molecules are multifunctional nano hybrid molecules with three-dimensional configuration, and the molecular formula is [ RSiO ]1.5]n(R is an organic functional group, n-6, 8, 10, 12, n-8 being the most common). The POSS molecule is internally provided with an inorganic core formed by silicon-oxygen-silicon bonds, and has the characteristics of certain rigidity and regularity, good thermal stability, radiation resistance, gas permeability and the like; the hollow structure of the POSS endows the POSS with the characteristic of light weight; in addition, the silica structure endows POSS with low specific surface energy, and POSS molecules can be subjected to structured self-assembly to form a micro-nano structure, so that the POSS material has certain liquid-repellent capacity; the outermost periphery of POSS is an organic group, and the change of the substituent group endows POSS with more functions. The POSS structure perfectly combines the advantages of organic structural units and inorganic structural units, wherein the inorganic component endows the POSS with good thermal stability, chemical stability and low surface energy; the organic component is easy to be functionally modified, and the diversity of POSS types can be realized.
To improve the liquid repellency of a surface, the surface is typically modified with a lower surface energy substance. Fluorine-containing compounds are a class of low surface energy materials that are typically doped with some substrate to render the material hydrophobic or even oleophobic. However, the disadvantages of fluorine-containing compounds that are generally incompatible with the substrate and difficult to degrade limit their use to some extent. The fluorine-containing POSS is prepared by combining the fluorine-containing compound and the silsesquioxane, the problem of phase separation is solved on the molecular level, and the advantages of the fluorine-containing POSS and the silsesquioxane are combined to a certain extent, so that the compound has a lower specific surface energy, and the temperature resistance of the compound is improved.
The cotton fabric is a material capable of being developed sustainably, the surface of the cotton fabric is modified, and the cotton fabric has research value and practical significance in the performances of water resistance, stain resistance, flame retardance, bacteria resistance and the like. Therefore, modification of cotton fabrics by POSS is a work with research significance. For example: chinese patent document CN106637959A provides a fluorine-free water repellent finishing method for cotton fabric based on ultraviolet curing reaction, which comprises: placing the cotton fabric in a 3-mercaptopropyltriethoxysilane ethyl acetate solution for mercapto modification to obtain a pretreated cotton fabric; the hydrosulphonyl modified cotton fabric is dipped in the solution of the vinyl cage type silsesquioxane, and the water repellent cotton fabric with the surface close to the super-hydrophobic effect is obtained under the ultraviolet curing condition. However, the preparation steps of the method relate to two-step heterogeneous reaction, are relatively complex, and the result of modifying the hydrophobicity of the fabric is still not ideal. Chinese patent document CN110172831A provides a hydrophilic after-finishing method for fabric, which comprises the steps of cleaning the fabric, and putting the cleaned fabric into a hydrophilic fabric finishing agent containing cage-type polysilsesquioxane and graphene for after-finishing; the fabric finishing agent containing cage-type polysilsesquioxane and graphene is prepared by reacting graphene oxide with a coupling agent containing vinyl silane, then carrying out mercapto-alkene click chemical reaction on the reaction product and octa (3-mercaptopropyl) cage-type polysilsesquioxane, carrying out mercapto-alkene click chemical reaction on the reaction product and the coupling agent containing vinyl silane, finally carrying out mercapto-alkene click chemical reaction on the reaction product and allyl polyether, and then reducing the graphene oxide. The fabric obtained by the hydrophilic after-finishing method of the fabric has the characteristics of better hydrophilicity, conductivity, ultraviolet resistance and washability, and the application range of the fabric is widened. However, the method introduces low surface energy silsesquioxane which acts as a cross-linking agent, but has certain influence on the hydrophilicity of the fabric, and influences the performance of the fabric. Chinese patent document CN109914108A provides a water repellent finishing method for polyester fabric, which comprises: (1) cleaning the polyester fabric, treating with a concentrated alkali solution, wrapping with a polyethylene film, baking, neutralizing with an acid solution, and washing with water to be neutral to obtain a pretreated polyester fabric; (2) placing the pretreated polyester fabric in an ethyl acetate solution of 3-mercaptopropyltriethoxysilane, and carrying out mercapto modification to obtain a mercapto-modified polyester fabric; (3) and (2) dipping the sulfydryl modified polyester fabric into a POSS solution or a mixed solution of POSS and long-chain alkyl mercaptan, and carrying out ultraviolet curing to obtain the modified polyester fabric. However, the method has the disadvantages of complicated fabric pretreatment process, use of high-concentration strong alkali, environmental friendliness and single fabric stability detection means.
In recent years, the use of POSS to modify cotton fabrics is gradually noticed by people, but the POSS is single in type and cannot be fully utilized, the research on the fluorine-containing POSS is rare, and at present, the POSS is used to modify the cotton fabrics, so that firm chemical bond support is lacked between the POSS and the fabrics, and the defect of poor stability exists. Therefore, the modification of the cotton fabric by using the fluorine-containing POSS has important significance in improving the stability of the cotton fabric. The invention is therefore proposed.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a preparation method of a stable perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric. According to the invention, the perfluoro-hexyl functionalized active POSS is used for carrying out surface modification on the cotton fabric, and the active trimethoxy silicon base or triethoxy silicon base is connected on the perfluoro-hexyl functionalized POSS, so that a stable chemical bond can be formed with the hydroxyl on the surface of the fabric, the stability of the modified cotton fabric is enhanced, and the obtained modified cotton fabric has super-amphiphobic properties of super-hydrophobicity and super-lipophobicity and has excellent liquid resistance; the obtained modified cotton fabric has great application potential in the aspects of stain resistance and self cleaning.
The technical scheme of the invention is as follows:
a preparation method of a stable perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric comprises the following steps:
(1) adding octamercaptopropyl polyhedral oligomeric silsesquioxane, perfluorohexylethylene and vinyl silane into a solvent, then adding a photoinitiator, uniformly mixing, and carrying out a photocatalytic reaction to obtain a perfluorohexylPOSS solution;
(2) soaking a cotton fabric in the perfluorohexyl POSS solution obtained in the step (1), hydrolyzing the soaked cotton fabric in an alkaline environment, and drying to obtain the stable perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric.
According to the invention, preferably, the octamercaptopropyl polyhedral oligomeric silsesquioxane (octamercaptopropyl POSS) in the step (1) is prepared into white translucent crystals, namely octamercaptopropyl POSS, by utilizing the hydrolytic condensation of mercaptopropyl trimethoxysilane according to the method shown in the document adv.Funct.Mater.2011,21, 2960-.
Preferably according to the invention, the vinyl silane in step (1) is trimethoxy vinyl silane or triethoxy vinyl silane.
Preferably according to the present invention, the ratio of the number of moles of octamercaptopropyl cage silsesquioxane in step (1) to the total number of moles of perfluorohexylethylene and vinylsilane is 1: 8; the molar ratio of perfluorohexylethylene to vinylsilane is 1-7:7-1, more preferably 1:7, 2:6, 3:5, 4:4, 5:3, 6:2 or 7:1, and still more preferably 7: 1.
According to the present invention, the solvent in step (1) is preferably tetrahydrofuran, diethyl ether, dichloromethane, chloroform, o-dichlorobenzene, 1, 2-dichloroethane, N-dimethylformamide or dimethylsulfoxide, and more preferably tetrahydrofuran.
Preferably, in step (1), the photoinitiator is 2, 2-dimethoxy-2-phenylacetophenone, 2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexylphenone, ethyl 4-dimethylaminobenzoate, benzophenone, 4-chlorobenzophenone, 4-methylbenzophenone or methyl o-benzoylbenzoate; the addition amount of the photoinitiator is 0.1-5 wt% of the mass of the octamercaptopropyl cage-type silsesquioxane.
According to the present invention, the photocatalytic reaction time in the step (1) is preferably 10 to 120 minutes, and more preferably 40 to 60 minutes; the light source of the light for the photocatalytic reaction is a 100W ultraviolet lamp, and the wavelength is 10-400 nm.
According to the invention, the concentration of the perfluorohexyl POSS in the perfluorohexyl POSS solution in the step (1) is preferably 10-110mg/mL, and more preferably 50-90 mg/mL; the mass of perfluorohexyl POSS is the sum of the mass of octamercaptopropyl cage silsesquioxane, perfluorohexyl ethylene and vinyl silane.
According to the present invention, the soaking time in the step (2) is preferably 1 to 24 hours, and more preferably 4 to 10 hours; the volume ratio of the cotton fabric to the perfluorohexyl POSS solution is not particularly limited, and the solution can be ensured to be completely immersed in the cotton fabric.
Preferably, in step (2), the alkaline environment is in an ammonia atmosphere, and the hydrolysis time is 10-120 min; preferably, the hydrolysis step is specifically: and under a closed condition, placing the soaked cotton fabric above ammonia water, and hydrolyzing under the atmosphere of ammonia gas provided by ammonia water volatilization, wherein the temperature of the ammonia water is 20-90 ℃, more preferably 40-45 ℃, and the concentration of the ammonia water is 25-28 wt%.
Preferably, according to the present invention, the drying temperature in step (2) is 30 to 100 ℃, more preferably 50 to 60 ℃; the drying time is 0.5 to 5 hours, and more preferably 1 hour.
The structural formula of the octamercaptopropyl polyhedral oligomeric silsesquioxane used in the invention is shown as the following formula:
the invention has the following technical characteristics and beneficial effects:
1. according to the invention, sulfydryl-alkene click reaction is adopted, and the proportion of perfluorohexyl ethylene and vinyl silane is adjusted to synthesize perfluorohexyl functionalized POSS with different substituent proportions, so that fluorine-containing structural materials for modifying cotton fabrics are enriched, then the perfluorohexyl functionalized POSS is used for modifying the cotton fabrics, the functionalized POSS-based coatings are connected on the surfaces of the cotton fabrics in a covalent bond mode, and the obtained modified cotton fabrics have good chemical stability and mechanical stability, and excellent wear resistance, stripping resistance, high temperature resistance, ultraviolet radiation resistance and acid-base salt corrosion resistance.
2. The perfluorohexyl functionalized POSS super-amphiphobic coating on the surface of the cotton fabric can effectively improve the mechanical stability of the modified cotton fabric, reaction sites are reserved on the POSS and connected with vinyl trimethoxy or vinyl triethoxy silicon base, and the methoxy or ethoxy can be subjected to dehydration condensation with hydroxyl on the surface of the cotton fabric after hydrolysis to form firm chemical bonds, so that the POSS is firmly combined on the surface of the cotton fabric, the mechanical stability of the modified cotton fabric is improved, and the modified cotton fabric is wear-resistant, stripping-resistant, radiation-resistant and the like; perfluorohexyl is introduced into POSS, so that the POSS modified cotton fabric has the advantages of reduced surface energy and chemical stability, and can resist acid, alkali, corrosion of salt solution and the like. Contact angle tests show that the water contact angle of the cotton fabric can reach more than 165 degrees, the rolling angle is lower than 10 degrees, the contact angle for part of oily liquid is more than 150 degrees, the rolling angle is also lower than 10 degrees, the ultra-hydrophobic and ultra-oleophobic properties are achieved, and the liquid resistance performance is excellent.
3. The raw materials needed by the invention are cheap and easy to obtain, no expensive catalyst is needed, the heating process is not needed in the synthesis process, the reaction can be carried out at room temperature, and the reaction condition is mild; the modified cotton fabric obtained by the invention has great application potential in the aspects of stain resistance and self cleaning.
Drawings
FIG. 1 is a nuclear magnetic resonance hydrogen spectrum of octamercaptopropyl POSS used in the examples.
FIG. 2 is SEM images of pure cotton fabric (a, c) and modified cotton fabric (b, d) obtained in example 7 at different magnifications.
FIG. 3 is an XPS summary spectrum (a) of a clean cotton fabric and a modified cotton fabric obtained in example 7; pure cotton fabric C1sA spectrum (b); modified Cotton Fabric C obtained in example 71sSpectrum (c).
FIG. 4 is a graph of the water contact drop shape of samples of perfluorohexyl functionalized reactive POSS based super-amphiphobic coating modified cotton fabric prepared in examples 1-7 and comparative example 1 of test example 1 followed from left to right by examples 1-7 and comparative example 1.
FIG. 5 is a graph of the change in water contact angle of the modified cotton fabric obtained after soaking in the perfluorohexyl POSS solution of test example 2 at different concentrations.
FIG. 6 is a graph of the change in water contact angle of the modified cotton fabric obtained in test example 3 at different soaking times.
Figure 7 is the contact angle of different droplets on modified cotton fabric in test example 4.
FIG. 8 is the change in water contact angle of the modified cotton fabric of test example 5 after a rubbing cycle.
FIG. 9 is the change in water contact angle after the modified cotton fabric of test example 5 has been subjected to a tape stripping cycle.
FIG. 10 is the change in water contact angle of the modified cotton fabric of test example 5 after the high temperature treatment.
FIG. 11 is the change in water contact angle of the modified cotton fabric of test example 5 after UV irradiation.
FIG. 12 is the change in water contact angle of the modified cotton fabric of test example 5 after soaking in an acid-base salt.
FIG. 13 is a photograph of the stain resistance of the modified cotton fabric of test example 5, the left image being the contaminated water dyed with methyl blue dye, and the right image being the muddy water.
FIG. 14 is a photograph of the self-cleaning of the modified cotton fabric of test example 5.
Detailed Description
The invention is further described below with reference to specific experimental examples and with reference to the drawings, but the scope of protection of the invention is not limited thereto.
The raw materials used in the examples are conventional raw materials and can be obtained commercially; the methods are prior art unless otherwise specified.
The octamercaptopropyl polyhedral oligomeric silsesquioxane used in the examples was prepared according to the literature procedures (adv. funct. mater.2011,21, 2960-: 360mL of methanol, 15mL of mercaptopropyl trimethoxysilane and 30mL of concentrated hydrochloric acid are added into a 500mL single-neck bottle to react for 24 hours at 90 ℃, the obtained solid is washed three times by the methanol, the solid is dissolved by dichloromethane and washed three times by water, the organic phase is collected and dried by anhydrous sodium sulfate, and the dichloromethane is removed under reduced pressure to obtain white semitransparent solid, namely the octamercaptopropyl POSS. The nuclear magnetic resonance hydrogen spectrogram of the octamercaptopropyl cage-type silsesquioxane is shown in figure 1.
The concentration of ammonia used in the examples was 27% by weight.
Example 1
A preparation method of a stable perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric comprises the following steps:
(1) in a dry 50mL beaker with magnetic stirring, 0.500g octamercaptopropyl polyhedral oligomeric silsesquioxane, 0.170g perfluorohexylethylene, 0.511g trimethoxyvinylsilane, and 23.6mL Tetrahydrofuran (THF) were added, followed by addition of 0.0176g 2, 2-dimethoxy-2-phenylacetophenone (DMPA), followed by uniform mixing, and reaction with stirring at room temperature for 60 minutes under illumination with a 100W ultraviolet lamp having a wavelength of 365nm to obtain a perfluorohexylPOSS solution.
(2) And (2) soaking a 5 cm-by-5 cm cotton fabric into the perfluorohexyl POSS solution obtained in the step (1), standing and soaking for 4 hours, taking out, placing the soaked cotton fabric above ammonia water at 45 ℃ under a closed condition, hydrolyzing for 20 minutes under the atmosphere of ammonia provided by volatilization of the ammonia water, and then drying for 1 hour at 60 ℃ to obtain a single perfluorohexyl-heptatrimethoxysilyl substituted POSS modified cotton fabric which is the perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric (sample 1).
Example 2
A preparation method of a stable perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric comprises the following steps:
(1) in a dry 50mL beaker with magnetic stirring, 0.500g octamercaptopropyl polyhedral oligomeric silsesquioxane, 0.341g perfluorohexylethylene, 0.438g trimethoxyvinylsilane, and 25.5mL Tetrahydrofuran (THF) were added, followed by addition of 0.0176g 2, 2-dimethoxy-2-phenylacetophenone (DMPA), followed by uniform mixing, and reaction with stirring at room temperature for 60 minutes under illumination with a 100W ultraviolet lamp having a wavelength of 365nm to obtain a perfluorohexylPOSS solution.
(2) And (2) soaking a 5 cm-by-5 cm cotton fabric into the perfluorohexyl POSS solution obtained in the step (1), standing and soaking for 4 hours, taking out, placing the soaked cotton fabric above ammonia water at 45 ℃ under a closed condition, hydrolyzing for 20 minutes under the atmosphere of ammonia provided by volatilization of the ammonia water, and then drying for 1 hour at 60 ℃ to obtain a diperfluorohexyl-hexa-trimethoxy silicon-based POSS-substituted POSS modified cotton fabric which is the perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric (sample 2).
Example 3
A preparation method of a stable perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric comprises the following steps:
(1) in a dry 50mL beaker with magnetic stirring, 0.500g octamercaptopropyl polyhedral oligomeric silsesquioxane, 0.511g perfluorohexylethylene, 0.365g trimethoxyvinylsilane, and 27.5mL Tetrahydrofuran (THF) were added, followed by addition of 0.0176g 2, 2-dimethoxy-2-phenylacetophenone (DMPA), followed by uniform mixing, and reaction with stirring at room temperature for 60 minutes under illumination with a 100W ultraviolet lamp having a wavelength of 365nm to obtain a perfluorohexylPOSS solution.
(2) And (2) soaking a 5 cm-by-5 cm cotton fabric into the perfluorohexyl POSS solution obtained in the step (1), standing and soaking for 4 hours, taking out, placing the soaked cotton fabric above ammonia water at 45 ℃ under a closed condition, hydrolyzing for 20 minutes under the atmosphere of ammonia provided by volatilization of the ammonia water, and then drying for 1 hour at 60 ℃ to obtain a tri-perfluorohexyl-penta-trimethoxy silicon-based POSS-substituted POSS modified cotton fabric which is the perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric (sample 3).
Example 4
A preparation method of a stable perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric comprises the following steps:
(1) in a dry 50mL beaker with magnetic stirring, 0.500g octamercaptopropyl polyhedral oligomeric silsesquioxane, 0.681g perfluorohexylethylene, 0.292g trimethoxyvinylsilane, and 29.4mL Tetrahydrofuran (THF) were added, followed by 0.0176g 2, 2-dimethoxy-2-phenylacetophenone (DMPA) and, after uniform mixing, reaction was carried out with stirring at room temperature for 60 minutes under a 100W ultraviolet lamp with a wavelength of 365nm to obtain a perfluorohexylPOSS solution.
(2) And (2) soaking a 5 cm-by-5 cm cotton fabric into the perfluorohexyl POSS solution obtained in the step (1), standing and soaking for 4 hours, taking out, placing the soaked cotton fabric above ammonia water at 45 ℃ under a closed condition, hydrolyzing for 20 minutes under the atmosphere of ammonia provided by volatilization of the ammonia water, and then drying for 1 hour at 60 ℃ to obtain the tetraperfluorohexyl-tetratrimethoxysilyl substituted POSS modified cotton fabric, namely the perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric (sample 4).
Example 5
A preparation method of a stable perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric comprises the following steps:
(1) in a dry 50mL beaker with magnetic stirring, 0.500g octamercaptopropyl polyhedral oligomeric silsesquioxane, 0.851g perfluorohexylethylene, 0.219g trimethoxyvinylsilane, and 31.4mL Tetrahydrofuran (THF) were added, followed by 0.0176g 2, 2-dimethoxy-2-phenylacetophenone (DMPA) and, after uniform mixing, reaction was stirred at room temperature for 60 minutes under 100W ultraviolet lamp at a wavelength of 365nm to obtain a perfluorohexylPOSS solution.
(2) And (2) soaking a 5 cm-by-5 cm cotton fabric into the perfluorohexyl POSS solution obtained in the step (1), standing and soaking for 4 hours, taking out, placing the soaked cotton fabric above ammonia water at 45 ℃ under a closed condition, hydrolyzing for 20 minutes under the atmosphere of ammonia provided by volatilization of the ammonia water, and then drying for 1 hour at 60 ℃ to obtain a pentaperfluorohexyl-trimethoxysilyl substituted POSS modified cotton fabric which is the perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric (sample 5).
Example 6
A preparation method of a stable perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric comprises the following steps:
(1) in a dry 50mL beaker with magnetic stirring, 0.500g octamercaptopropyl polyhedral oligomeric silsesquioxane, 1.022g perfluorohexyl ethylene, 0.146g trimethoxy vinyl silane, and 33.0mL Tetrahydrofuran (THF) were added, followed by addition of 0.0176g 2, 2-dimethoxy-2-phenyl acetophenone (DMPA), and after uniform mixing, the mixture was stirred and reacted at room temperature for 60 minutes under a 100W ultraviolet lamp with a wavelength of 365nm to obtain a perfluorohexyl POSS solution.
(2) And (2) soaking a 5 cm-by-5 cm cotton fabric into the perfluorohexyl POSS solution obtained in the step (1), standing and soaking for 4 hours, taking out, placing the soaked cotton fabric above ammonia water at 45 ℃ under a closed condition, hydrolyzing for 20 minutes under the atmosphere of ammonia provided by volatilization of the ammonia water, and then drying for 1 hour at 60 ℃ to obtain a hexaperfluorohexyl-trimethoxysilyl substituted POSS modified cotton fabric which is the perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric (sample 6).
Example 7
A preparation method of a stable perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric comprises the following steps:
(1) in a dry 50mL beaker with magnetic stirring, 0.500g octamercaptopropyl polyhedral oligomeric silsesquioxane, 1.192g perfluorohexylethylene, 0.073g trimethoxyvinylsilane, and 35.0mL Tetrahydrofuran (THF) were added, followed by addition of 0.0176g 2, 2-dimethoxy-2-phenylacetophenone (DMPA), followed by uniform mixing, and reaction with stirring at room temperature for 60 minutes under a 100W ultraviolet lamp with a wavelength of 365nm to obtain a perfluorohexylPOSS solution.
(2) And (2) soaking a 5 cm-by-5 cm cotton fabric into the perfluorohexyl POSS solution obtained in the step (1), standing and soaking for 4 hours, taking out, placing the soaked cotton fabric above ammonia water at 45 ℃ under a closed condition, hydrolyzing for 20 minutes under the atmosphere of ammonia provided by volatilization of the ammonia water, and then drying for 1 hour at 60 ℃ to obtain a heptaperfluorohexyl-single trimethoxysilyl substituted POSS modified cotton fabric, namely the perfluorohexyl functionalized active POSS-based super-amphiphobic coating modified cotton fabric (sample 7).
Pure cotton fabric and the modified cotton fabric obtained in this example were compared, and the surface of the fabric was characterized by a field emission Scanning Electron Microscope (SEM) and an in situ X-ray photoelectron spectrometer (XPS), the results of which are shown in fig. 2 and 3, respectively. As can be seen from fig. 2, the surface of the pure cotton fabric is relatively smooth; after modification, the surface of the cotton fabric becomes rough, particles are attached, the surface of the fabric has a micro-nano structure, and adhesion occurs among fibers, which shows that perfluorohexyl POSS is successfully connected to the surface of the fabric. Further, surface chemical analysis was performed on the surface of the modified cotton fabric using XPS, as shown in fig. 3, the modified cotton fabric was newly added with F compared to the pure cotton fabric1s，S2s、S2p，Si2s、Si2pThis indicates that the compound used for modification successfully attached to the surface of the cotton fabric. Peaks of C ═ O, C-O and C-C/C-H at 287.8eV, 286.3eV and 284.7eV in the spectrum of pure cotton fabric C1s, and peaks of C-F at 294.3eV, 292.0eV, 289.0eV, 286.3eV, 286.1eV, 285.1eV and 284.1eV in the spectrum of modified cotton fabric3，C-F2Peaks of C-O, C-C, C-S, C-H, C-Si, there was some change in the position of the peaks after coating.
Comparative example 1
A preparation method of POSS-based coating modified cotton fabric comprises the following steps:
(1) in a dry 50mL beaker with magnetic stirring, 0.500g octamercaptopropyl polyhedral oligomeric silsesquioxane, 0.584g trimethoxyvinylsilane, 21.7mL Tetrahydrofuran (THF) was added, followed by 0.0176g 2, 2-dimethoxy-2-phenylacetophenone (DMPA) was added, and after uniform mixing, the mixture was stirred at room temperature for 60 minutes under a 100W ultraviolet lamp at a wavelength of 365nm to obtain a POSS solution.
(2) And (2) soaking a 5 cm-by-5 cm cotton fabric into the POSS solution obtained in the step (1), standing and soaking for 4 hours, taking out, placing the soaked cotton fabric above ammonia water at 45 ℃ under a closed condition, hydrolyzing for 20 minutes under the atmosphere of ammonia gas provided by ammonia water volatilization, and drying for 1 hour at 60 ℃ to obtain the octa-trimethoxy silicon-based POSS-substituted modified cotton fabric, namely the POSS-based coating modified cotton fabric (sample 8).
Test example 1
The samples obtained in examples 1 to 7 and comparative example 1 were evaluated for their liquid repellency by the change in water contact angle, and the results are shown in FIG. 4, and specific contact angle data are shown in Table 1.
TABLE 1
Numbering
Sample 1
Sample 2
Sample 3
Sample No. 4
Sample No. 5
Sample No. 6
Sample 7
Sample 8
Water contact angle/° c
151.8±1
152.2±1
154.2±3
153.6±2
158.8±3
160.8±3
161.8±2
140.2±2
From the data of water contact angle in fig. 4 and table 1, it can be concluded that the hydrophobic properties of the modified cotton fabric are gradually improved as the content of perfluorohexyl substituent increases, mainly because the increase of perfluorohexyl favors the decrease of surface energy; meanwhile, hydrophilic silicon hydroxyl groups can be generated after hydrolysis of trimethoxy silicon groups, the trimethoxy silicon groups can not be completely connected to the surface of the cotton fabric due to steric hindrance, a part of free silicon hydroxyl groups can be generated, the hydrophobic performance is gradually improved along with the reduction of the number of the trimethoxy silicon groups, and a sample 8 cannot reach a super-hydrophobic state due to the fact that the sample contains more silicon hydroxyl groups. It can be concluded that sample 7 is the best performing product.
Test example 2
Exploring process conditions: optimal soaking concentration of cotton fabric in perfluorohexyl POSS solution
According to the preparation method shown in example 7, perfluorohexyl POSS solution with perfluorohexyl POSS concentration of 110mg/mL is prepared by changing the amount of tetrahydrofuran to 16mL, then solutions with concentrations of 10, 30, 50, 70, 90 and 110mg/mL are respectively obtained by a dilution method, the soaking time of cotton fabrics is fixed to 5 hours, and then modified cotton fabrics soaked in different concentrations are obtained. The optimal soaking concentration of the obtained cotton fabric is searched through the change of the water contact angle, the result is shown in figure 5, the water contact angle is gradually increased along with the increase of the soaking concentration, when the concentration is 70mg/mL, the contact angle reaches 164.6 degrees, then the contact angle is not obviously changed along with the further increase of the concentration, and the optimal soaking concentration is determined to be 70mg/mL in consideration of the economic principle.
Test example 3
Exploring process conditions: optimum soaking time
According to the preparation method shown in example 7, soaking solutions with perfluorohexyl POSS concentration of 70mg/mL were prepared by changing the amount of solvent used (25.2 mL with tetrahydrofuran added), and cotton fabrics were soaked for different times of 1,2, 3, 4, 5, 6, 7, 8, 9, 10 hours, respectively, followed by obtaining modified cotton fabrics soaked for different times. The optimal soaking concentration of the obtained cotton fabric is explored through the change of the water contact angle, as shown in fig. 6, the water contact angle is gradually increased along with the increase of the soaking time, the contact angle of the cotton fabric obtained after soaking for 7 hours reaches 165.2 degrees, then the contact angle is not obviously changed along with the further increase of the soaking time, and the optimal soaking time is determined to be 7 hours.
Test example 4
Example 7 super-amphiphobic Performance test of the resulting modified Cotton Fabric
Selecting liquids with different surface energies to perform a contact angle test, wherein the liquids comprise water, glycerol, dimethyl sulfoxide and n-hexadecane, the surface tensions of the liquids are 72.8mN/m, 64mN/m, 43.5mN/m and 27.5mN/m respectively, and the hydrophobicity and the oleophobicity of the modified cotton fabric are researched. As shown in FIG. 7, the contact angle decreases as the surface energy of the liquid decreases, and the contact angle for glycerol and dimethylsulfoxide was 150 ℃ or more.
Test example 5
According to the method shown in example 7, modified cotton fabric was prepared under the conditions of perfluorohexyl POSS concentration of 70mg/mL and soaking time of 7 hours by exploring the process conditions, and the obtained modified cotton fabric was subjected to a stability test.
Mechanical stability research of modified cotton fabric
(1) Abrasion resistance test
The modified cotton fabric was fixed on a 200g weight, placed on 600 mesh sandpaper, pulled straight 10cm at a speed of 4cm/s, and pulled 10cm in the vertical direction as a one-pass cycle. The results are shown in fig. 8, after 150 cycles of rubbing, the contact angle can still be above 150 °, indicating that the modified cotton fabric has good wear resistance.
(2) Tape peel test
The surface of the modified cotton fabric is pasted by a commercial transparent adhesive tape and peeled within one second, so that the cycle is realized. The results are shown in fig. 9, after 220 tape stripping cycles, the cotton fabric contact angle is still above 150 °, indicating that the modified cotton fabric has good peel stability.
(3) High temperature resistance test
The modified cotton fabric is placed in a constant temperature environment with different temperatures of 100-200 ℃, is placed for 1 hour, the water contact angle is tested every 20 ℃, the temperature resistance of the modified cotton fabric is researched through the change of the contact angle, and the result is shown in figure 10, the contact angle of the cotton fabric is increased from 165.2 degrees to 167.7 degrees within the temperature of 100-140 ℃, but at 160, the water contact angle begins to be reduced, and the surface of the modified cotton fabric begins to yellow. The result shows that the long chain containing fluorine migrates to the surface of the fabric at high temperature to improve the hydrophobicity, and when the temperature reaches 160 ℃, the long chain containing fluorine starts to decompose to reduce the hydrophobicity, thus the modified cotton fabric can resist the high temperature of 140 ℃.
(4) Resistance to ultraviolet radiation
The modified cotton fabric is irradiated under a 45W ultraviolet lamp, the distance between the cotton fabric and a lamp holder is 15cm, the cotton fabric is taken out at an interval of 10 hours, and the ultraviolet radiation resistance of the cotton fabric is researched. The results are shown in fig. 11, the hydrophobic properties of the cotton fabric are substantially unchanged after 90 hours of uv irradiation, indicating that the modified cotton fabric has good uv irradiation resistance.
(5) Research on chemical stability of modified cotton fabric
Acid and alkali salt solution resistance test
Soaking cotton fabric in acid-base solution (sodium hydroxide and hydrochloric acid solution) with pH of 1-14 and 1mol/L sodium chloride solution for 24 hr, taking out, washing with deionized water, and drying. Chemical stability was explored by using changes in the water contact angle. The results are shown in fig. 12, the contact angle is reduced in acidic solution and alkaline solution, and is reduced more in alkaline solution, but the contact angle is still above 150 degrees, and the change of the contact angle in salt solution is small, which indicates that the modified cotton fabric has good chemical stability against acid-base salt.
(6) Anti-fouling, self-cleaning applications
The modified cotton fabric has good liquid resistance, so the modified cotton fabric has potential application value in the aspects of stain resistance and self cleaning. As shown in fig. 13, the cotton fabric is soaked in the muddy water and the sewage dyed by the methylene blue dye and then taken out, so that the surface of the cotton fabric is not polluted and has the anti-fouling capability; as shown in figure 14, when the surface of the cotton fabric is polluted, the polluted fabric can be taken out by simply washing the surface with water, and the cotton fabric has self-cleaning capability.
The above-mentioned embodiments are merely preferred embodiments of the present invention, and are not intended to limit the present invention.