Epoxy thermoset coatings with fine controllable hierarchical structures prepared from bio-inspired photo-/colloidal lithography technique for anticorrosion application

Abstract

Several epoxy thermoset (ET) composite coatings with artificial fine controllable micro/nano hierarchical structures were prepared through photolithography/colloidal lithography and subsequently applied in anticorrosion field. Firstly, several silicon wafers with fine controllable interspacing and width of micro-scaled cylindrical structures were fabricated through conventional photolithography. Subsequently, nano-scaled tips were fabricated upon a smooth clean surface on the previous silicon wafer with micro-scaled cylinders to generate nano-scaled tips through colloidal lithography. Moreover, ET coatings were duplicated by nano-casting technique with polydimethylsiloxane (PDMS) as a soft negative template. Surface morphology and contact angle (CA) of as-prepared hard silicon template and ET coatings were identified. The CA of water droplets on ET coating with bio-inspired micro/nano hierarchical structures (denoted by BET) was 160°, which meant that this coating was more hydrophobic than ET coatings with distinctive surface structures. Anticorrosion studies of as-prepared ET coating with/without distinctive structures showed that cold rod steel (CRS) electrode coated with BET had better anticorrosion performance than other ET coating for short- and long-term studies. This procedure of fine controllable micro/nano structure coatings opens the door for further innovative investigations of corrosion protection methods and material designs.