Preparation of Core-Shell Microspheres by Changing Reaction Solvent

We have successfully prepared monodispersed core-shell microspheres with polystyrene cores and poly(N-isopropylacrylamide) shells by changing solvent from nonpolar to polar for the first time. Effects of stirring time and reaction temperature on the particle size, monodispersity of the microspheres were investigated. With increasing stirring time at 800 rpm, the size of the spheres and the monodispersity are the best when stirring time is 60 min.. And with increasing reaction temperature (above phase transition), the size of the microspheres decreases and the monodispersity becomes better.