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.

Automated summary

A novel, facile and continuous flow photopolymerization of Pickering emulsion method was used to fabricate nanoporous composite microspheres. Palygorskite (PAL) fibers were chosen as stabilizers in the oil phase system, which included Methyl methacrylate (MMA), (ethylene glycol) diacrylate (EGDMA), Irgacure 819 (I 819, photoinitiator), and toluene (porogenic agent). The influence of PAL concentration on the emulsion stability and the morphology of the microspheres was fully investigated. It was found that the presence of 1.5 wt% PAL fibers provided the best conditions for obtaining polymerized porous microspheres. N-2 adsorption-desorption isotherm characterization revealed a specific BET surface area of 171 m(2)/g, indicating the great potential applications of this methodology. Suitable polymerization flow rate was also found to be a key parameter for the formation of PMMA/PAL composite microspheres. The formation mechanism and porosity of the microspheres were discussed.