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Polymer Coatings Based on Nanocomposites
Published in Sanjay Mavinkere Rangappa, Jyotishkumar Parameswaranpillai, Suchart Siengchin, Polymer Coatings, 2020
Liliana Licea-Jiménez, Ulises Antonio Méndez-Romero, Abraham Méndez-Reséndiz, Arturo Román Vázquez-Velázquez, Ricardo Antonio Mendoza-Jiménez, Diego Fernando Rodíguez-Díaz, Sergio Alfonso Pérez-García
In self-cleaning coatings, the counterpart of superhydrophilic coatings are the superhydrophobic ones. A superhydrophobic coating can be understood primarily because it is governed by a process similar to the lotus effect; this feature allows the waterdrop to remove and to carry particles of soiling from the surface of the material, keeping the surface clean (Valipour, Birjandi, and Sargolzaei 2014). The growing need to achieve a self-cleaning property through a superhydrophobic coating has generated the development of different strategies. It is known that to obtain these coatings, there are key issues: roughness at a nanometric scale and NPs with hydrophobic features and good polymeric affinity. The proper interaction permits surfaces with high water contact angle and the development of polymeric coatings–based nanocomposites. However, not all the materials present hydrophobic features, so chemical surface modification is required. These modifications can be carried on through a functionalization process, producing a chemical change on the material surface (Ma and Hill 2006).
Superhydrophobic Organic-Inorganic Nanohybrids
Published in Chang-Sik Ha, Saravanan Nagappan, Hydrophobic and Superhydrophobic Organic-Inorganic Nanohybrids, 2018
Chang-Sik Ha, Saravanan Nagappan
Solution immersion is the most prominent method to fabricate a superhydrophobic coating due to easy and simple method of surface modification on various substrates. The superhydrophobic coating can be obtained using a one-or two-step immersion process. In most cases, the substrates are pre-etched in a strong basic or acidic solution to form a rough surface morphology on the substrate coated with thin films of hydrophobic materials to produce a superhydrophobic surface on the substrate. Various hydrophobic organic or inorganicorganic materials have been used to develop superhydrophobic surfaces on various substrates by a simple immersion technique. Moreover, the immersion technique is environmentally friendly and reduces the time of preparation and materials consumption, and energy.
The preparation and properties study of novel hydrophobic/superhdrophobic coatings based on fluorine modified perhydropolysilazane
Published in Journal of Dispersion Science and Technology, 2023
Jianxin Zhu, Guoping Shen, Weizhong Jiang, Xuan Shen
As Shown in Figure 5a, the surface of the 304 stainless steel wire drawing board is hydrophilic, and water droplets spray on the surface. The CAwater of 304 stainless steel wire drawing board is 37.8°. As shown in Figure 5c and 5e, the water droplets spread neither on hydrophobic coating nor on superhydrophobic coating. CAwater of the hydrophobic coating and superhydrophobic coating are 113.0° and 150.1°, respectively. However, with the same coating method, the CAwater of perhydropolysilazane coating is only 91.0° (Figure 5b). The introduction of fluorine to perhydropolysilazanes can increase the CAwater by 22°, which further demonstrated the improvement of hydrophobicity of the coatings modified by fluorine. In addition, the surface of the hydrophobic coating (Figure 5d) is smoother than that of the superhydrophobic coating (Figure 5f). The rougher structure of the superhydrophobic coating make the contact area smaller between water droplets and the coating surface, thus exhibits better hydrophobicity.
Durable superhydrophobic coatings based on flower-like zinc oxide via layer by layer spraying
Published in The Journal of Adhesion, 2022
Yan Bao, Pei Tang, Xiujuan Shi, Lu Gao
Thus, we aimed to prepare a durable superhydrophobic coating via a simple method in this work, which is suitable for industrial application in outdoor environmental conditions. In order to achieve the above purpose, the superhydrophobic coating based on F-ZnO was obtained via layer-by-layer spraying method. F-ZnO with an obvious micro-nanometer scale rough structure was prepared by chemical precipitation. The F-ZnO was used to induce rough micro-nanometer scale structures and endow the coating with excellent UV resistance. ER served as an adhesive was applied to render mechanical strength and coating-substrate adhesion, improving the wear resistance of the coating. Furthermore, ER has good adaptability to extreme weather conditions, which is of great benefit to the durability of the coating. PDMS with low surface energy served as the uppermost skin of the coating was employed to further improve the superhydrophobic performance of the coating. The effects of MF-ZnO: MER and MPDMS: MF-ZnO on the hydrophobicity and mechanical durability of the coating were studied. The as-prepared coating showed excellent stability against abrasion, outstanding high- and low-temperature stability, significant UV resistance, and prominent anti-fouling property for common liquid stains and muddy water. This method was applied to cotton fabric finishing, which also presented noticeable superhydrophobicity and anti-fouling performance. All the results exhibited the merits of this coating, including simple process, easily large-scale fabrication, superhydrophobicity, durability, suitable for different substrates, fluorine-free, and environment friendly.
Preparation, characterisation, and anti-icing properties of superhydrophobic coatings on asphalt mixture
Published in International Journal of Pavement Engineering, 2022
Yi Zhao, Kaiqi Wen, Jia Wang, Zhen Yang, Min Qin
The silicone oligomer was prepared by silane coupling agent KH550, MTMS and DMDS under acidic condition. The hydrophobicity of silica can be improved by reducing the amount of hydroxyl groups on the surface of silica. The chemical reaction formulas are shown in Figure 2. In this study, the spraying method was used to prepare the superhydrophobic coating (Zhao et al.2018). The spraying amount was 0.89 L/m2.