Fabrication of hierarchical porous fluoro-PolyHIPE materials with ultra-high specific surface area via hypercrosslinking knitting technique

Fluoro-PolyHIPEs with porous structure exhibit an excellent weather resistance for adsorption, separation or catalyst support applications in extreme environments, however, the specific surface area still needs to be improved. In this study, a porous fluorinated material is prepared by using high internal phase emulsion template method, and the porous structure of fluoro-PolyHIPE (F-PolyHIPE) is subsequently excavated and modified by the hypercrosslinking "knitting" method. The "knitting" of micropores in the pore walls of the fluoropolymer is achieved through the Friedel-Crafts alkylation reaction by using dimethoxymethane (FDA) as the external crosslinker. It transforms the macroporous fluoropolymer prepared based on HIPE emulsion template method into hierarchical porous fluoro-PolyHIPE (HCPF-PolyHIPE) with a high specific surface area. The specific surface area of the porous fluorinated material demonstrates an increment from 15.6 m(2) g(-1) to 353.2 m(2) g(-1) after hypercrosslinking. Owing to the introduction of the micropores and mesopores as well as the enrichment of the fluorine atoms in the polymer network, HCPF-PolyHIPE can be successfully applied for CO2 adsorption, thus, representing a major achievement of the study. Moreover, HCPF-PolyHIPE exhibits excellent thermal stability as well as acid and alkali resistance, thus, confirming potential application prospects in the fields of oil-water separation and gas adsorption.