Enhancing the Robustness of Superhydrophobic Coatings via the Addition of Sulfide

Langmuir. 2019 May 21;35(20):6650-6656. doi: 10.1021/acs.langmuir.9b00690. Epub 2019 Apr 30.

Abstract

Micro/nano hierarchical structures with special wettability impart a wide spectrum of unique properties to the superhydrophobic surfaces that are applicable in different potential fields. Therefore, it is necessary to develop advanced superhydrophobic materials with excellent wear-resistance properties. In this study, PDMS-based robust superhydrophobic coatings, which used MoS2 or WS2 as a solid lubricant, PDMS as a binder, and SiO2 as a filler, were prepared on glass substrate by the one-step air spaying method. Lamellar MoS2 and WS2 with high crystallinity had intrinsic hydrophobic properties. The MoS2@SiO2-PDMS (MSP) and WS2@SiO2-PDMS (WSP) coatings with very rough textures showed good water-repellent behavior with water contact angles of 167.8 and 166.2°, respectively. The results demonstrated that the addition of microsized MoS2 or WS2 could easily format micro/nano second-level hierarchical structures, thus realizing the superhydrophobic properties. The friction coefficient decreased gradually with the increasing in MoS2 or WS2. A 4:1 ratio of SiO2 to MoS2/WS2 could cause the samples to preserve their superhydrophobic properties even after 100 cycles on the abraser. As a result, superhydrophobic coatings with excellent wear resistance will be good candidates for water-repellent surfaces to meet practical emerging needs in industry applications.