Preparation of Uniform and Heterogeneous Structure Polystyrene Particles by Premix Membrane Emulsification
ZHU Lin GONG Fang-ling, YUAN Qi-peng MA Guang-hui
Key Laboratory of Bioprocess of Beijing, Beijing University of Chemical Technology State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences School of Life Science and Technology, Beijing University of Chemical Technology State Key Lab. Biochem. Eng., Inst. Process Eng., Chinese Academy of Sciences
Abstract：Uniform polystyrene (PST) particles with controlled heterogeneous structure were synthesized by premix membrane emulsification method, the effects of the emulsification pressure and cycles, pore size of the membrane used, and porogen on the PST particle size and uniformity were studied. The results indicate that the membrane pore size has linear relation with the average diameter of PST particles and is in inverse proportion to the optimum emulsification pressure. The prepared PST particle sizes can be controlled in 1~6 mm with the size distribution index Span of 0.8, and the relative standard deviation of reproducibility within 3%. Furthermore, the degree of phase separation between polymers and porogen decreases with decreasing of the particle size. Liquid paraffin is unsuitable as the porous medium for the particle size smaller than 2 mm, hexadecane can be used as macroporous medium but with the dosage of under 60% when the particle size is larger than 2 mm.
2013, Vol. 13 
