Preparation of polysulfone-coated chitosan beads by emulsion phase-inversion method

A new coating method of emulsion phase-inversion method was suggested, and crosslinked chitosan beads coated with a thin polysulfone (PSF) layer were prepared with the new coating method. The emulsion was composed of PSF, dimethylformamide (DMF), paraffin, and Span 80 as the emulsifier. The effects of the swelling ratio (water content), PSF concentration, phase ratio between PSF in DMF solution and the paraffin phase, as well as coating time on the microstructures and thickness of the coating layer were investigated. The microstructures of the coating layer were determined by SEM microphotographs. Experimental results show that the thickness and the microstructures of the coating layer can be easily controlled with the new coating method. By changing the swelling ratio, PSF concentration, phase ratio in the emulsion, and the coating time, the desired coating layer can be achieved. (C) 2004 Wiley Periodicals, Inc.