Effect of Silica Size and Content on Superamphiphobic Properties of Silica-Fluoropolymer Core-Shell Coatings.

Jiyoung Lee,Ha Soo Hwang,In Park,Tien N H Lo,Won-Gun Koh

doi:10.3390/polym12122864

Abstract

We present a facile approach to fabricate superamphiphobic surfaces by spray coating silica-fluoropolymer core-shell particles without substrate pretreatment with an additional binder resin. A series of SiO2@poly(1H,1H,2H,2H-heptadecafluorodecyl methacrylate) (SiO2@PFMA) core-shell particles with core particles of different sizes were prepared via thiol-lactam initiated radical polymerization (TLIRP). The surface of each SiO2 particle with an average particle size of 12, 80, 150, and 350 nm was modified with (3-mercaptopropyl) trimethoxysilane and used as a seed for TLIRP. The SiO2@PFMA particles with various SiO2 sizes and contents were coated on aluminum substrates by a spray gun and then thermally treated to form a stable, rough composite layer. During the spray coating, the core-shell particles were aggregated by rapid evaporation of the solvent and then irregularly adhered to the substrate resulting in hierarchical structures. In the case of SiO2@PFMAs with low SiO2 contents, the roughness created mainly by the polymer shell disappeared during heat treatment. However, the substrates coated with SiO2@PFMAs with high SiO2 contents maintained the roughness even after heat treatment. The core-shell particles prepared with 12 nm SiO2 formed a stable superamphiphobic surface. The water/hexadecane contact and sliding angles on an aluminum plate coated with SiO2@PFMA, prepared using 12 nm silica at 46 wt% silica content (12 nm-SiO2(46)@PFMA), were 178.5°/159.2° and 1°/7°, respectively. The cross-cut tape test showed that adhesion between the 12nm-SiO2(46)@PFMA and the aluminum substrate was classified as 5B. A glass surface spray-coated with the core-shell composite particles exhibited transparent superhydrophobicity and translucent superamphiphobicity by controlling the concentration of the coating solution.

Highlights

Over the past decade, superamphiphobic surfaces with both superhydrophobic and superoleophobic properties have drawn considerable interest in research and industrial applications [1,2,3,4,5]
SiO2 @PFMA core-shell particles were successfully synthesized via surface-initiated thiol-lactam initiated radical polymerization (TLIRP) in the presence of SiO2 –SH and BL
SiO2 @PFMA particles were spray-coated onto aluminum substrates to produce superamphiphobic surfaces, and they were thermally treated at temperatures above Tm to improve the olephobicity of the coated materials

Summary

Introduction

Superamphiphobic surfaces with both superhydrophobic and superoleophobic properties have drawn considerable interest in research and industrial applications [1,2,3,4,5]. Applying superhydrophobic technology to self-cleaning surfaces is effective in removing water-borne contamination, but the surfaces tend to be wet by oils rather . Oil- and water-borne contaminants bead up and readily roll-off from superamphiphobic surfaces. The superamphiphobic surface is useful for a variety of applications such as self-cleaning [12,13], anti-fouling [14], corrosion resistance [15], and anti-icing [16,17]. Obtaining a superamphiphobic surface is challenging because organic liquids with low surface energy readily spread on most solid surfaces and on superhydrophobic surfaces. To fabricate a superamphiphobic surface, it is necessary to develop a technology that combines elements such as low surface energy materials [18], fractal structure [19], and re-entrant features [8]

Methods

Results

Conclusion