In this work, we proposed a mild and fluorine-free strategy for fabricating robust superhydrophobic coatings with TiO
2
, 3-mercaptopropyltriethoxysilane (MPTS) and polyhedral oligomeric ...silsesquioxanes using dip-coating and thiol-ene click reaction. The modified cotton exhibited superb superhydrophobicity with a WCA of 157.6°, which showed anti-wetting property in both water and air. Moreover, the durability of the treated cotton against acid and alkaline solutions, different temperatures, abrasion and peeling tests was verified. The highlight is the dual self-cleaning afforded by superhydrophobicity and photocatalytic degradation. The oil red O was adopted as organic pollutant model and could be decomposed completely with the aid of resultant coating after UV irradiation for 3 h. In addition, the modified cotton could be used as filter material and has the potential in the application of oil–water separation. After seven separation cycles, the separation efficiency still maintained 99.0%, while the WCA of cotton kept as high as 154.6°. Therefore, the above-mentioned features demonstrated that this fluorine-free method could reduce the usage of long-chain fluorinated polymers and prepare superhydrophobic cotton which could be applied in self-cleaning as well as oil–water separation fields.
Graphic abstract
Robust superhydrophobic cotton textiles exhibiting photocatalytic self-cleaning ability under UV light were successfully achieved by surface functionalization with anatase TiO
2
sol and mercapto ...silanes, and hydrophobization with vinyl-terminated polydimethylsiloxane (V-PDMS) via thiol-ene click reaction. The modified cotton textiles not only showed outstanding water repellency with a water contact angle of 154.2°, but exhibited desirable photodegradation of oil red O by photocatalysis under UV irradiation. Moreover, the modified textiles exhibited excellent durability and stability after exposure to different severe conditions, such as acid and base solutions, organic solvents, laundering and UV exposure. The durably coated textiles manifested desirable separation performance in oil–water mixtures, and the separation efficiency was about 99.0% even after 20 times use. Cotton textiles with multi-functionality of superhydrophobicity, photocatalysis and oil-water separation are hopefully applied in a diverse range of practical applications in self-cleaning and oil-removal fields.
Nanofiber bundles with specific areas bring a new opportunity for selective adsorption and oil/water or air separation. In this work, nanofiber bundles were prepared by the electrospinning of ...immiscible polystyrene (PS)/N-trifluoroacetylated polyamide 6 (PA6-TFAA) blends via the introduction of carbon nanotubes (CNTs) or a copolymer of styrene and 3-isopropenyl-α, α’-dimethylbenzene isocyanate (TMI), which was denoted as PS-co-TMI. Herein, CNT was used to increase the conductivity of the precursor for enhancing the stretch of PS droplets under the same electric field, and PS-co-TMI was used as a reactive compatibilizer to improve the compatibility of a PS/PA6-TFAA blend system for promoting the deformation. Those obtained nanofiber bundle membranes showed an increase in tensile strength and high hydrophobicity with a water contact angle of about 145.0 ± 0.5°. Owing to the special structure, the membranes also possessed a high oil adsorption capacity of 31.0 to 61.3 g/g for different oils. Moreover, it exhibits a high potential for gravity-driven oil/water separation. For example, those membranes had above 99% separation efficiency for silicon oil/water and paraffin wax/water. Furthermore, the air filtration efficiency of nanofiber bundle membranes could reach above 96%, which might be two to six times higher than the filtration efficiency of neat PS membranes.
In this paper, various fabrics with good self-cleaning performance were prepared via a facile dip-coating method. The fabrics composed with different fibers and woven techniques were firstly immersed ...in ZnO sol to increase the surface roughness, then dip-coated in fluoroalkylsilane (HFT) solution to reduce the surface energy. The coated fabric showed excellent superhydrophobicity with a water contact angle (WCA) of 157.8° and water shedding angle (WSA) of 5 °. The morphologies and chemical compositions of prepared fabrics were observed with SEM, XPS and EDS. The obtained fabric kept stable water-repelling property in acidic and alkaline solutions, solvents and UV irradiation. Benefited from its high antiwater ability and photocatalysis function of ZnO, the coated fabric demonstrated excellent self-cleaning performance. This versatile approach of constructing superhydrophobic fabrics is attractive and could be large-scaled employed in industrial production process.
Fluorinated (meth) acrylate oligomer modified epoxy resin (PHFBMA-DGEBA) and polyether-modified epoxy resin (MPEG-DGEBA) were successfully synthesized and used as reactive modifier and emulsifier for ...epoxy resins, respectively. GPC, FTIR and
1
H NMR were employed to verify the synthesis. The influence of both the concentration and the molecular weight of PHFBMA-DGEBA on the properties of waterborne epoxy resin coatings was investigated. Surface energy and surface composition were probed by contact angle measurements and X-ray photoelectron spectroscopy (XPS), which strongly confirmed the enrichment of fluorinate atoms on the surface. The surface energy of waterborne epoxy coating was decreased from 44.46 mN/m to 23.20 mN/m by adding just 0.09 wt% PHFBMADGEBA-2, indicating its high effectiveness in improving the surface hydrophobicity. Moreover, the physical properties of waterborne epoxy coatings prepared with different concentration and molecular weight of fluorinated reactive modifier, such as water absorption, Shore D hardness, adhesion, thermal properties and optical transmittance, were also analyzed in detail. Taken together, the waterborne epoxy coatings prepared with low concentrations of reactive modifier are economical and have great potential in large scale industry applications.
Waterborne difunctional polyacrylate with long fluorinated side chains and epoxy groups (WALF) was successfully synthesized and used as emulsifier and reactive surface modifier for epoxy resin. The ...structure of WALF was characterized by FTIR and
1
H NMR. In order to investigate the effect of the length and the content of the fluorinated side chains on the properties of the epoxy thermosets, a waterborne difunctional polyacrylate with short fluorinated side chains and epoxy groups (WASF) was developed as a contrast modifier. The waterborne epoxy emulsion modified by WALF or WASF was prepared through phase inversion method. Transmission electron microscopy (TEM) signified that the waterborne epoxy emulsion has a particle size range of 201.4–590.2 nm, indicating excellent water dispersion property. In addition, the surface properties, thermal properties, and mechanical properties of the waterborne epoxy coating were also analyzed in detail. Compared with WASF, the epoxy coating modified by WALF had higher surface fluorine atomic concentration, lower surface energy, and higher thermal stability.
•A facile and mild sol-gel method to fabricate superhydrophobic cotton fabric.•The surface was prepared by a one-step process with fluorinated TiO2 sols.•Modified fabrics exhibit excellent chemical ...resistance to organic and pH solution.
The purpose of this paper is to propose a facile, green and low-cost approach of the preparation of superhydrophobic cotton textiles, which can be fabricated with fluorinated TiO2 sols via a sol-gel method. The coating was prepared with TiO2 sols catalyzed with acetic acid, then modified by poly(Hexafluorobutyl methacrylate) (PHFBMA) which was synthesized by free radical polymerization. The wettability, surface morphology and chemical composition of pristine and modified cotton fabrics were investigated. The modified fabric presents a high contact angle reached up to 152.5°. The successful incorporation of fluorinated TiO2 nanoparticles into cotton fabric was verified by the above measurements results. Additionally, the chemical stability of the coated fabric has been tested by immersing in different pH solutions and organic solvents, demonstrating the outstanding water repellency of the fabric. Furthermore, the treated cotton fabric shows excellent self-cleaning properties, which makes it an ideal material for large-scaled industrial applications in various conditions.
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•Robust superhydrophobic fabrics were achieved by thiol-ene click reaction.•The resultant fabric exhibited both physical and chemical self-cleaning properties.•The resultant fabric ...displayed oil-water separation efficiency and recyclability.•The resultant fabric exhibited excellent chemical and mechanical stability.
Robust superhydrophobic fabric (SF) was successfully achieved by surface modification with anatase TiO2 sol and mercapto silanes, subsequently followed by hydrophobization with perfluorooctyl methacrylate (PFOMA) via thiol-ene click reaction. The resultant SFs not only exhibited excellent superhydrophobicity with a water contact angle of 157.7° and a water shedding angle of 4°, but also showed the considerable photocatalytic activity by the degradation of oil red O under UV irradiation. Moreover, the SFs exhibited a wetting transition from a superhydrophobic state to a superhydrophilic state by the alternation of UV exposure and thermal treatment. The SF could be utilized to separate oil-water mixture owing to its superhydrophobicity and superoleophilicity. Importantly, the SFs were tolerant towards strong acidic or alkaline environments, corrosive organic solvents, laundering, and mechanical abrasion. In addition, this facile preparation process could impart the superhydrophobicity to other substrates (such as PET fabrics, nonwoven fabrics, and sponges). Therefore, superhydrophobic materials with multi-functionality of UV induced reversible wettability, photocatalytic self-cleaning property, and oil-water separation are regarded as promising candidates for a wide range of applications.
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For waterborne coating, there is still inevitable defects (insufficient anti-corrosion performance). In this paper, the functional graphene oxide (TDPG) is prepared via self-prepared ...polymer (triethylene tetramine-polyethylene glycol diglycidyl ether). The TDPG is used to modify waterborne polyurethane (WPU) coating for improving anti-corrosion property. The electrochemical impedance spectroscopy and salt spray test are used to evaluate the corrosion resistance ability of composite coating. The WPU/ TDPG0.05 owns optimal corrosion resistance property. After 30 days immersion in 3.5 wt.% NaCl solution, the impedance modulus Zf = 10mHz of WPU decreases to 6.17 × 106 Ω·cm2 from 1.36 × 107 Ω·cm2, but the Zf = 10mHz of WPU/TDPG0.05 decreases to 9.48 × 106 Ω·cm2 from 2.39 × 107 Ω·cm2. By Tafel test, the corrosion potential of WPU/TDPG0.05 is -0.056 v, which is more positive than that of WPU (-0.224 v). The corrosion current and polarization resistance of WPU/TDPG0.05 are 1.30 × 10−8 A/cm2 and 3.4 × 106 Ω·cm2, respectively. Moreover, the adhesion strength of WPU/TDPG0.05 decreases to 5.89 MPa from 6.69 MPa, only losing 16.96 %.
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Multifunction of cotton textiles with superhydrophobicity, UV protection, self-cleaning and oil-water separation is of interest for diverse practical applications. Herein, we report a ...simple and cost-effective dip-coating route to prepare superhydrophobic cotton textiles by using ZnO sol and 3-Mercaptopyl trimethoxysilane (MTS), and then introducing dodecafluoroheptyl methacrylate (DFMA) via thiol-ene click reaction. The coated cotton textile displayed excellent superhydrophobic ability with a water contact angle of 156.3° and a shedding angle of 6° when the concentration of DFMA was 10%. The chemical stability of the obtained sample was further evaluated by immersion in acid and alkaline solutions, salt solution and organic solvents, exhibiting wonderful chemical resistance of coating. Laundering and abrasion tests revealed the excellent mechanical stability of coating. Moreover, the modified cotton textile had good UV stability and shielding properties. Furthermore, this cotton showed outstanding self-cleaning and oil-water separation properties, which is promising and suitable for large-scale industrial applications.
