Preparation of golf ball-shaped microspheres with fluorinated polycaprolactone via single-solvent electrospraying for superhydrophobic coatings

Abstract

Abstract 1H,1H,2H,2H-Perfluorooctyl polyacrylate (PTFOA) with a controllable molecular weight was successfully synthesized via atom-transfer radical polymerization (ATRP) followed by condensation with polycaprolactone (PCL) to obtain a new fluorinated block copolymer. Then, the copolymer PCL-b-PTFOA was processed via single-solvent electrospraying in chloroform to fabricate hierarchically porous microspheres. The microsphere size could be controlled from 5.13\u2009±\u20090.51\u2009μm to 8.61\u2009±\u20090.90\u2009μm, and the pore size on the microsphere surface could be controlled from 282.5\u2009±\u200942.0\u2009nm to 603.3\u2009±\u200999.6\u2009nm. Solvent evaporation-induced phase separation and fluorinated segment migration are the major reasons for the formation of the golf ball-shaped microspheres. In this study, the influence of electro-spraying parameters on the size and morphology of the porous microspheres was systemically studied. The golf ball-shaped microspheres significantly improved the surface roughness and the CA of their coatings reached 167.3\u2009±\u20091.7°. Furthermore, a superhydrophobic fabric was produced by pretreating cotton fabric with adhesive followed by coating with PCL-b-PTFOA via electrospraying. The robust superhydrophobicity can be obtained by the stable binding of PCL-b-PTFOA microspheres onto the fibers, with the CA reaching 155.3\u2009±\u20091.1°. Electrospraying of the fluoropolymer microsphere coating was proven to be a very promising technique to produce superhydrophobic coatings on textiles through a simple procedure.