Design of Infused-Liquid-Switchable Superamphiphilic and Flame-Retardant Hierarchically Porous Materials from Emulsion-Templated Technique

The serious oil pollution from oil spillages and industrialprocessesnot only causes severe environmental and ecological damage but alsocreates a risk of fire and explosion. Therefore, it is imperative,also challenging, to find high-performance oil/water separation materialsthat are effective and incombustible. Herein, hierarchically porouspolyphosphazene (PSZ) monoliths, having an intelligent superamphiphilicityand high flame retardance, are constructed via an emulsion-templatingstrategy. A high-temperature-resistant high internal phase emulsion(HIPE) is designed for the first time to synthesize PSZ from hexachlorocyclotriphosphazeneand 3, 3 & PRIME;-diaminobenzidine. The synthesis of PSZ guaranteesthe formation of a mesostructured framework. Meanwhile, the dropletsof the emulsion as sacrificial templates provide the formation ofmicron-scale voids in the monolith. The hierarchically porous structurecombining the amphiphilic nature of PSZ endows the monolith with aninfuse-liquid-switchable superamphiphilic performance, i.e., superhydrophobicunder oil and superoleophobic under water. Also, due to its highlypermeable structure, the PSZ monolith is proven to be highly efficientfor continuously and simultaneously separating oil and water fromemulsion. Moreover, the intrinsic flame retardance of PSZ makes themonolith possess excellent flame retardancy (UL-94-V-0 grade, LOIof 27.4%), which is thus expected to reduce the risk of fire and explosionwhen being used to separate oil and water.