CAJ | 학술논문

采用油包水包油(O/W/O)复相乳化悬浮交联的方法制备壳聚糖多孔微球,以低毒和无毒的乙酸乙酯和蓖麻油为制孔剂和非水溶性分散介质替代常用的具有一定毒性的有机分散刺甲苯和液体石蜡.乙酸乙酯先在壳聚糖醋酸溶液中乳化.然后上述乳液在蓖麻油中进一步反相乳化,采用戊二醛对壳聚糖分散相进行交联、同化.对制备工艺中影响壳聚糖多孔微球的多孔结构、粒径以及孔隙率等性能的影响因素进行了研究和优化.
채용유포수포유(O/W/O)복상유화현부교련적방법제비각취당다공미구,이저독화무독적을산을지화비마유위제공제화비수용성분산개질체대상용적구유일정독성적유궤분산자갑분화액체석사.을산을지선재각취당작산용액중유화.연후상술유액재비마유중진일보반상유화,채용무이철대각취당분산상진행교련、동화.대제비공예중영향각취당다공미구적다공결구、립경이급공극솔등성능적영향인소진행료연구화우화.
Chitosan, in particular with a format of microspheres, has been extensively employed in many applications, that is, treatment of wastewater, chromatographic support, enzyme immobilization, drug delivery, dental application, and hemostasis. In this paper, porous chitosan microspheres were prepared by oil-in-water-in-oil (O/W/O) multiple emulsion crosslinking method. The low toxic and nontoxic solvents, ethyl acetate and castor oil, were applied as a cavity generating agent and a water-insoluble dispersion medium, respectively, to replace the commonly used toxic oil phase such as petroleum ether, toluene and paraffin. The low molecular weight chitosan was obtained by the depolymerization of raw chitosan with hydroperoxide. The viscosity molecular weight (Mw) of the ehitosan was investigated by using an Ubbelohde viscosimeter and calculated based on Mark Houwink equation. For preparation of the porous chitosan microspheres, ethyl acetate was first emulsified in chitosan acetic acid solution, and subsequently the emulsion was inversely dispersed in castor oil. The chitosan micro-droplets were solidified and hardened by glutaraldehyde as crosslinking agent. All the preparation process was carried out at room temperature. The stirring rate of the emulsion, ehitosan concentration, ethyl acetate/chitosan solution ratio, chitosan solution/castor oil ratio, and glutaraldehyde concentration were studied as effective preparation parameters on the size, size distribution and porosity of the chitosan microspheres. The chitosan microspheres were filtrated and rinsed with ethanol and water to remove the organic solvent and the surfaetants. Finally, the porous chitosan microspheres were obtained by freeze-drying. The number average diameter of the optimized example of chitosan microspheres was 51.2μm. The porous structures distributed in the chitosan microspheres were clearly observed by the SEM.