Fabrication of porous poly(methyl methacrylate)/palygorskite microspheres via pickering emulsion templated continuous-flow photopolymerization

A novel and facile continuous flow photopolymerization of Pickering emulsion procedure to fabricate nanoporous composite microspheres was induced. Palygorskite (PAL) fibers were chosen as stabilizers in oil phase system that containing of Methyl methacrylate (MMA), (ethylene glycol) diacrylate (EGDMA), Irgacure 819 (I 819, photoinitiator) and toluene (porogenic agent). The influence of PAL concentration to the emulsion stabilities and the morphologies of produced microspheres have been fully investigated. It was observed that in the presence of 1.5 wt% PAL fibers, the formed pickering emulsion provided best conditions to obtain polymerized porous microspheres. Furthermore, N 2 adsorption-desorption isotherms characterization revealed a specific BET surface area of 171 m 2 /g of the resultant microspheres, which suggested the great potential applications of such methodology. Suitable polymerization flow rate is one of the other key parameters to result PMMA/PAL composite microspheres. Additionally, the formation mechanism of the microsphere as well as its porosity has been discussed.