(467c) Preparation of Uniform-Sized Functional Microsphere with Nano-Porous Structure

Microspheres with nano-porous structure have important applications in immobilization of enzymes and preparation of artificial cells. However, the size distribution of microspheres prepared by conventional suspension polymerization methods is usually broad, which is not desired for the above applications. In this study, uniform-sized microspheres with functional group were prepared by combining a special glass membrane emulsification technique and a subsequent suspension polymerization process. That is, a mixture composed of functional monomer, crosslinker, diluent and initiator was pressed through the pores of the membrane into an aqueous phase to form uniform droplets under a controlled pressure, then the droplets were polymerized by elevating the temperature. The parity of functional monomer is usually higher, it is difficult to obtain uniform droplet by a direct membrane emulsification technique because it wetted the membrane easily, a swelling technique of droplet was developed to attain to the purpose. In addition, when the monomer was polarity, it was difficult to obtain microspheres with porous structure on the surface, microspheres with porous structure inside and a skin on the surface usually were formed. The mechanism for it was discussed and the microspheres with homogeneous porous structure were prepared successfully. The hollow microsphere with a porous wall was also prepared in order to construct an artificial cell.