Controllable Superhydrophobic Coating on Cotton Fabric by UV Induced Thiol-ene Reaction for Wettability Patterning and Device Metallization

Superhydrophobic surfaces in nature have attracted a great deal of interest not only for fundamental understanding but also for practical applications through mimicking the nature. Fluorochemicals, due to their intrinsic low surface energy, have been widely applied as artificial superhydrophobic functionalization materials with excellent performance. However, the use of these materials for practical applications might be restricted due to the relative high cost and potential hazards to human health. In this work, a low-cost and environmentally friendly short silane chain material is developed for fabricating superhydrophobic surfaces. A transparent photoactive coating is obtained by polycondensation of trichlorovinylsilane on cotton fabrics. The coating shows excellent superhydrophobicity. After being grafted with vinyl group, the coating can be easily functionalized using a photoclick thiol-ene reaction. The thiol-ene reaction has resulted in highly uniform polymer networks, which makes it possible to realize the rapid wettability switch from superhydrophobic to superhydrophilic state. Such ability makes it potentially viable to prepare well-defined cotton patterning by printing, and realize flexible electronic devices when electrodes are printed on the fabrics.