Creating monodisperse polymer microspheres using membrane emulsification.

ABSTRACT This study used membrane emulsification (ME) as a pre-treatment step to suspension polymerization to produce polystyrene microspheres with diameters from 200 to 300 µm and coefficient of variation (CV) as low 20%. Limited scientific information is available on utilizing suspension polymerization to prepare monodisperse polystyrene microspheres with diameters greater than 100 µm. Microspheres were produced by pumping monomer solution through uniform pores of nickel membranes to form dispersed phase droplets that were transferred to a reactor for suspension polymerization. Systematic studies were done to understand the roles of continuous phase composition, ME unit process parameters, and polymerization reactor stir speed on microsphere size and CV. For a specific microsphere size, there were particular stir speeds in each unit that minimized CV. The methodology developed in this study is being used to prepare monodisperse polymer resin beads to improve detection efficiency and accuracy in flow-cell sensors for quantifying waterborne radioactivity. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44593. [ABSTRACT FROM AUTHOR]