Robust translucent superhydrophobic PDMS/PMMA film by facile one-step spray for self-cleaning and efficient emulsion separation

In this work, a translucent superhydrophobic coating was fabricated by a simple spray-coating technique using fluorine-free and easily available materials, viz, the hybrids of PDMS and PMMA in THF solution, without any pre-/post-treatment. The combination of the microscale roughness of the sprayed-PMMA, along with the low surface energy PDMS, has contributed to the observed superhydrophobicity. The as-prepared PDMS/PMMA@superhydrophobic surface has displayed a water contact angle of 157.5° and sliding angle of 2.8°. Furthermore, the liquids with various surface tension, ranging from water to various organic liquids, displayed nearly spherical shapes on the superhydrophobic substrate. In addition, this coating has also shown significant stability against sand abrasion and water droplet impact, and was able to maintain its superhydrophobicity after being soaked in strong acid and salkali solutions. Moreover, the superhydrophobic coating was found to be translucent with good visibility of the characters through the coated glass substrate. The transformation from a superhydrophobic state to superhydrophilic state can be realized via a hot-press process, and such a facile technique can be easily applied to potential applications in surface patterning. Additionally, the super-antiwetting surface has been demonstrated for applications in highly efficient oil-water emulsion separation, anti-fouling, and self-cleaning.