Fabrication of Multifunctional Polyester Fabrics by Using Fluorinated Polymer Coatings

Facile and effective polymer coatings are highly desirable in the creation of functional surfaces for various applications. A polymer coating by using poly(vinylidene fluoride-co-hexafluoropropylene (PVDF-HFP) and a fluorinated alkyl silane (FAS-17) in volatile solvent has been proposed in the literature for the fabrication of chemically stable and superamphiphobic fabrics. This method, however, suffered from the fact that the results were unable to be experimentally reproduced by the authors. In this work, FAS-17-modified PVDF-HFP with surface energy of 14.04 mN/m was prepared through two-step reactions in acetone using coupling agent 3-aminopropyltrimethoxysilane (H₂N-(CH₂)_3-Si-(OCH₃)3) and 1H,1H,2H,2H-perfluorodecyltriethoxysilane (FAS-17, F₃C-(CF₂)₇-(CH₂)₂-Si-(OC₂H₅)3) in the first and second reaction steps, respectively. This coating solution was then applied onto the twill weave polyester fabric using a dip-coating method. The as-fabricated surfaces exhibited extreme liquid repellency as signified by high static contact angles (149.5 °−105.7 °) against six pure liquids (water, ethylene glycol, hexadecane, pentadecane, nonane, octane) with surface tension values ranging from 72.8 to 21.4 mN/m. Furthermore, this coating showed chemical stability to strong acid (96 % sulfuric acid) and strong base (38 % sodium hydroxide). In addition to self-cleaning property, the coating also exhibited self-healing property as revealed by the static contact angle change with the plasma-and-heat treatment cycles. Moreover, it is interesting to note that coating of fabrics with the pristine solution of PVDF-HFP and FAS-17 may instead find its potential applications in oil-water separation. High separation efficiency, stability, and reusability were exhibited by the as-fabricated separation membrane.