Durable superhydrophobic ZnO–SiO₂films: a new approach to enhance the abrasion resistant property of trimethylsilyl functionalized SiO₂nanoparticles on glass

Abstract

Although trimethylsilyl functionalized SiO 2 derived films show excellent superhydrophobicity, their adhesion and abrasion resistant properties are extremely poor. In this study, a new approach has been shown to improve the adhesion and abrasion properties of such films. A neutral and relatively hydrophobic [Zn(CH 3 OO) 2 (H 2 O) 2 ] complex solution has been used to interact with the superhydrophobic silica gel nanoparticle dispersion. After dip-coating, the composite sol yielded films of a zinc acetate/superhydrophobic silica composite network while the hydrophilic part (bonded water) associated with Zn helps in binding the hydroxyl groups (silanols) present on the glass surface. The composite films were heat-treated at 300-400 C in a nitrogen atmosphere in order to obtain transparent and superhydrophobic ZnO-SiO 2 nanocomposite films. The decomposition of zinc acetate formed ZnO nanocrystallites and remained attached with the hybrid silica matrix. These films showed excellent water repellency (water contact angle, CA z 158 AE 7 ; hysteresis z 4 ) with good adhesion and abrasion resistant properties. XRD, Raman and TEM studies confirm the existence of ZnO nanocrystallites in the composite films. Owing to the stability of hydrophobic methyl groups attached with silicon at relatively high temperature in a nitrogen atmosphere, these ZnO-SiO 2 nanocomposite films remain superhydrophobic even after a heat-treatment at 400 C.

Non-fluorinated superhydrophobic and micro/nano hierarchical Al doped ZnO film: the effect of Al doping on morphological and hydrophobic properties

“…The most common superhydrophobic surface can be fabricated via chemically modifying with low surface free energy organic peruorinated materials. [7][8][9][10][11] Being a wide band-gap semiconductor material, zinc oxide (ZnO) possesses various optical and electrical applications. 6 Therefore, increasing attention is drawn to fabricating superhydrophobic surfaces without any low energy organic materials, such as inorganic material lms with specic hierarchical rough surfaces.…”

Zeolite Crystals Embedded Nanotextured Coating with Hydrophobic Surface: An Innovation Toward Next Generation Solar Cover Glass for Efficient Light‐Harvesting

“…Figure b shows the image of nearly spherical shaped water drop on the visually transparent NTHH coated glass. After modification, the formation of such nearly spherical water drop can be explained due to the organically modified nanotextured surface of the coating (as observed in Figure ) . It is noteworthy here that no noticeable change in hydrophobic behavior of the durable NTHH coating was observed (Figure S5, Supporting Information) after adhesive tape test (as explained in the ‘Characterizations' section).…”

Improved Adhesion of Nonfluorinated ZnO Nanotriangle Superhydrophobic Layer on Glass Surface by Spray-Coating Method

“…The additional absorption bands identified at 2973 cm −1 and 2848 cm −1 are attributed to CH 3 and C-H band, respectively, which might be resulting from the acetate precursor [43]. The existence of bands near 1578 cm −1 and 1422 cm −1 is associated with the C=O stretching vibration of the acetate group [8], indicating the presence of acetate, which is deduced to be the possible functional group to anchor with silanol group of glass substrate. For DMDEOS (Figure 3(b)), the band observed at 3389 cm −1 is ascribed to the OH group, indicating that the silane group of DMDEOS is hydrolyzed by acid [44].…”

“…These surfaces are called as superhydrophobic with a water contact angle (WCA) higher than 150°and a sliding angle (SA) lower than 10° [6]. The following conditions are necessary to fabricate a superhydrophobic surface: (i) creation of hierarchical rough surface [7] and (ii) chemical modification of rough surface with low surface energy materials [8]. The most popular methods to create superhydrophobic surfaces are plasma etching [9], sol-gel [10], electrospinning [11], layer by layer assembly [12], phase separation [13], and solution immersion [14].…”

“…The usage of primes (epoxy) as a binder was a prerequisite to improve the adhesion of the coating. Das et al [8] examined the fabrication of robust superhydrophobic surface on glass using ZnO at high temperature curing (400°C). Simovich et al [35] fabricated a robust superhydrophobic surface by the combination of epoxy resin, hexamethylenediamine, and silica nanoparticles.…”