Synthesis of CO2-philic/hydrophilic surfactant with brush structure and its application in preparing monolithic material

Abstract A new strategy was developed to build a CO2-philic/hydrophilic surfactant by combining the common free radical polymerization and the grafting modification technology, and a brush polymer was synthesized with poly(vinyl acetate)-based copolymer as the CO2-philic group (as the main chain) and the methoxy polyethylene glycols (MPEG) as the hydrophilic part (as the branched chain) (PVAc-g-MPEG). The CO2-philic ability can be controlled by adjusting the chain length of the PVAc fragment. The results indicate that PVAc-g-MPEG has excellent surfactant activity, and can emulsify the CO2/H2O system to obtain the CO2-in-water (C/W) high interval phase emulsion (HIPE 80%, v/v), which can remain stable for more than 20 hours. If using the monomers/crosslinking agent solution instead of water, the highly porous monolithic materials will be obtained after the continuous phase is polymerized. In this paper, polyacrylamide (PAM) and poly(acrylamide/diethyl aminoethyl methacrylate)-based porous monolithic materials(PADM) were prepared. These materials were used to separate the protein (BSA as the model matter) from the solution, and the results indicated that PAM-based porous monolithic materials had almost no enrichment capacity for protein, while PADM-based porous monolithic materials can adsorb BSA up to 129.3 mg/g.