Preparation of silicone-PCL composite particles with hierarchical structure and the super-hydrophobic fabrics via directly electrostatic spraying

Abstract

Herein, microspheres with a rough structure were prepared via electrostatic spraying, using a spray solution prepared by dissolving poly(ε-caprolactone) (PCL) and ladder-like fluorinated polysilsesquioxane (F-PH-LPSQ) blends in chloroform. The effects of concentration, voltage, flow rate, receiving distance and blending ratio on the morphology and particle size distribution of the microspheres were investigated. The microsphere spray coatings prepared under different blending ratios were tested: the results demonstrate that the contact angles of the coatings all exceeded 150°, the rolling angles were all smaller than 1° and the adhesion forces were all <51 μN, thus displaying excellent superhydrophobicity. The formation mechanism of the ‘roughened’ microsphere morphology was explored by analysing the energy dispersive spectroscopy results and element content of the protruding and pitted parts of the sprayed particles. The spraying and blending ratio was optimised and determined to be 1.0:0.4. Subsequently, the PCL/F-PH-LPSQ microspheres were directly sprayed and coated with the developed spray solution via electrostatic spraying. The water contact angle of the finished cotton fabric was found to be ≥160°, which provided excellent hydrophobicity and self-cleaning function. Following the sandpaper abrasion and adhesion tests, the contact angle of the fabrics coated with the microspheres remained ≥155°,indicating a good mechanical stability.