Admicellar polymerization of a co-fluoropolymer ultrathin film on TiO2 nanoparticles for use as a photocatalytic cement

Abstract

Abstract TiO2 nanoparticles were surface-modified with a co-fluoropolymer of trifluoroethyl acrylate (TFEA) and octafluoropentyl methacrylate (OFPM) for in a surface-photocatalytic cement. An ultrathin coating of copolymer was formed by adapted step admicellar polymerization. Suitable conditions for admicellar polymerization with the commercial fluoro-surfactant FS 1620 were determined from measurement of the adsorption isotherm using HPLC. Modified TiO2 nanoparticles or fluoropolymer-coated titanium dioxide nanoparticles (FTDNPs) were characterized by FT-IR, SEM, EDS, particle analysis, TGA, contact angle and photocatalyst activity. FTDNPs clearly showed the presence of the co-fluoropolymer from FT-IR, SEM with EDS, TGA and hydrophobic character from a simple floating test and contact angle measurement. Surface-photocatalytic activity of cement containing FTDNPs was observed by methylene blue (MB) degradation. TiO2 nanoparticles after surface modification still exhibited the ability to function as a photocatalyst, despite being covered with co-fluoropolymer thin film. The fluorocarbon coating facilitated expulsion of FTDNPs to the cement surface during the hydration reaction.