Superhydrophobic al2o3-polymer composite coating for self-cleaning applications

Superhydrophobic coatings have a huge impact in various applications due to their extreme water-repellent properties. The main novelty of the current research work lies in the development of cheap, stable, superhydrophobic and self-cleaning coatings with extreme water-repellency. In this work, a composite of hydrothermally synthesized alumina (Al2O3), polymethylhydrosiloxane (PMHS) and polystyrene (PS) was deposited on a glass surface by a dip-coating technique. The Al2O3 nanoparticles form a rough structure, and low-surface-energy PHMS enhances the water-repellent properties. The composite coating revealed a water contact angle (WCA) of 171 ± 2° and a sliding angle (SA) of 3°. In the chemical analysis, Al2p, Si2p, O1s, and C1s elements were detected in the XPS survey. The prepared coating showed a self-cleaning property through the rolling action of water drops. Such a type of coating could have various industrial applications in the future.Funding: This research was funded by Department of Science and Technology (DST), Goernment of India. [DST/INSPIRE/04/2015/000281] and National Natural Science Foundation of China (21950410531).Scopu

Fabrication of robust self-cleaning superhydrophobic coating by deposition of polymer layer on candle soot surface

A facile and inexpensive way have been developed to fabricate robust self-cleaning superhydrophobic coating by depositing polymer layer on candle soot (CS) surface using dip coating method. The stability and robustness of the CS deposited superhydrophobic surface is much weaker due to weak interaction and nonchemical bonding with the substrate. We introduced a thin layer of polystyrene, polyethylene, polypropylene (PP), and polyvinylidene fluoride on CS surface in order to improve its mechanical properties. The fabricated surfaces with the use of respective polymers exhibited water contact angles of nearly 170, 174, 175, and 171° with sliding angles of 2, 1, 1, and 3°, respectively. Although, all the polymers used in this work exhibited excellent superhydrophobic and self-cleaning surface property, we found that the PP deposited CS surface exhibit better stability against water jet hitting and water drop impact tests. The PP deposited CS surface almost maintained their surface properties even after 50 cycles of sandpaper abrasion and 20 cycles of adhesive tape peeling tests. The mechanical durability tests confirmed that PP is a better polymer to improve the long-term durability of CS surface. Therefore, this simple, time saving, and inexpensive method for fabricating superhydrophobic coating can be used for potential industrial application.National Natural Science Foundation of China, Grant/Award Number: 21950410531; Henan University; DST ? INSPIRE Faculty Scheme, Department of Science and Technology (DST), Govt. of India, Grant/Award Number: DST/INSPIRE/04/2015/000281 Funding informationScopu

Photocatalytic and Superhydrophilic TiO2-SiO2 Coatings on Marble for Self-Cleaning Applications

The application of photocatalytic and self-cleaning titanium dioxide (TiO2) nanomaterials coating on the stone of architectural heritage (particularly on marble) can be used to preserve their aesthetic qualities. The present work describes the effect of dipping time on the wetting property of coatings and the effect of UV irradiation on the coating in terms of hydrophilicity. The suspension of TiO2-SiO2 is prepared by adding 30–50 nm in size TiO2 particles in the sol–gel processed SiO2 solution. The water contact angle (WCA) decreases with increasing dipping time of piece of marble in TiO2 – SiO2 suspension. Also the hydrophilicity of coating increases with increasing UV illumination time. The 2D and 3D laser microscope analysis revealed surface structure and stable surface roughness of 1.0 µm. Such type of superhydrophilic TiO2 – SiO2 coating may be used to protect architectural heritage and buildings.Scopu

Octadecyltrichlorosilane-Modified Superhydrophobic-Superoleophilic Stainless Steel Mesh for Oil-Water Separation

Recently, oil-water separation has become an important topic due to its increasing commercial demand. Here, in this study, a simple technique to prepare superhydrophobic-superoleophilic mesh for oil-water separation is reported. The pre-cleaned stainless steel mesh is modified by octadecyltrichlorosilane (ODS) through solution immersion method. The modified mesh shows the water contact angle (WCA) of 158 ± 2° and oil contact angle (OCA) of 0°. The prepared superhydrophobic-superoleophilic mesh effectively separates various oils, including petrol, kerosene, diesel, vegetable oil, and coconut oil from oil–water mixtures with separation efficiency greater than 95%, and stable recyclability up to 10 cycles. In case of low viscosity oil (petrol), the modified mesh shows permeation flux of 2086.95 ± 104.34 L/(m2.h), which is higher than high viscosity oilsThis work is financially supported by DST ? INSPIRE Faculty Scheme, Department of Science and Technology (DST), Govt. of India. [DST/INSPIRE/04/2015/000281]. S.S.L. acknowledges financial assistance from the Henan University, Kaifeng, P. R. China. The authors greatly appreciate the support of the National Natural Science Foundation of China (21950410531).Scopu