Facile manufacturing process of durable superamphiphobic and flame-retardant coatings based on layer-by-layer assembly

Abstract

A layer-by-layer (LBL) assembly method was firstly used to prepare a powder with both superamphiphobic and enhanced flame-retardant properties. The ammonium polyphosphate (APP) powder was used as a core to adsorb the branched poly (ethylenimine) (BPEI) and phytic acid (PA) by the principle of electrostatic attraction. After a bilayer of BPEI and perfluorooctanoic acid (PFOA) were further assembled onto the particle surface, superamphiphobic powder was obtained. Polydimethylsiloxane (PDMS) binder and superamphiphobic powder were mixed by the method of “two-layer glue + particle” to prepare superamphiphobic coating, which could provide superior mechanical durablility. The coating could be used on a variety of substrates, and had excellent superamphiphobic properties towards water and various kinds of low-surface-energy oils. The superamphiphobic surface achieved superior self-cleaning ability under diverse water and oil flux, and obtained good anti-fouling performance when immersed into various oils with high viscosity. The coated surface still showed good mechanical robustness of superamphiphobicity even when recycled abraded for 300 times. Moreover, owing to the good fire-retardant property of APP and the synergic effects among the polyelectrolytes, the coated fabric coated was difficult to ignite and could self-extinguish a flame within 6 s. This superamphiphobic and fire-retardant coating is considered to have a wide range of applications in many fields.