Transparent and anti-fouling perfluoropolyether coating with superior wear resistance

Perfluoropolyether (PFPE) siloxanes can be used as anti-fouling coating materials due to their simple large-scale preparation, transparency and omniphobic properties, but their wear resistance needs to be enhanced dramatically. Herein, we designed and synthesized a series of high-purity PFPE-siloxanes with different average molecular weights of PFPE chains and different numbers of trimethoxysilane groups. Then, these PFPE-siloxanes were coated on glass plates in a one-step dip coating process. The influence of the average molecular weight of PFPE chains and the number of trimethoxysilanes on the wear resistance of these PFPE films were investigated by the measurement of static contact angle and sliding angle of water, morphology and relative elemental content on the surface after different times of reciprocating friction. The film prepared from the PFPE-siloxanes combining a longer PFPE chain with more trimethoxysilane terminal groups possessed not only good transparency and excellent antifouling properties, but also presented superior wear resistance and anti-fingerprint properties. The surface wetting characteristic and morphology barely changed after 9000 times of friction with hard rubber under a 255 kPa pressure. The PFPE-siloxanes with excellent antifouling property and transparency make them as preferred candidates for engineering application fields.