微封装法制备空心塑料微球

THE FABRICATION OF HOLLOW PLASTIC MICROSPHERES BY MICROENCAPSULATION METHOD

采用微封装法，以聚苯乙烯（ＰＳ）为成球物质，对成球的乳化搅拌速度、溶液浓度、水／有机相体积比、实验温度及真空度等因素进行了研究。在此基础上，成功地制得了单壳ＰＳ空心微球。其几何参数为：直径１００～３００μｍ、壁厚２～８μｍ、球形度≥９５％、同心度≥９０％、表面粗糙度≤３００ｎｍ。

AbstractIn inertial-confinement fusion (ICF)researches,low-Zplastic microspheres used asfuel containers can provide more efficient ablative implosion and significantly reduceradiation preheat compared with the glass shells.The fabrication of plastic microspheres bymicroencapsulation method consists of three main stages which are described using thefollowing emulsion terminology:(W)defines the aqueous phase,(O)defines the organicphase. The W/O emulsion is first formed by adding water containing a small quantity of thesurfactant to a rappidly stirred organic solution. The W/O emulsion is then added to a largevolume of water also containing surfactant and by further stirring a(W/O)/W dispersionis formed consisting of water droplets encapsulated in a thin layer of polymeric solutionsuspended in water.By evaporating the solvent of organic phase,the plastic microsphereswhich encapsulate water in them are formed.After filtered the plastic microspheres aredried at a lower temperature to remove the interior water.Finally the hollow plasticmicrospheres are formed. Polystyrene (PS)was used as the material for the fabrication of microspheres.The mainparameters of microencapsulation method having influence on the size and quality ofmicrospheres,such as the emulsifying rotating speed,the concentration of solution,thevolume ratio of water/organic phases,the temperature and vacuum of operation werestudied.And PS microspheres with diameter from l00 to 300μm,wall thickness of 2 to 8μmwere produced.The microspheres concentricity,sphericity and surface roughnesses aretypically less than 5%, 10% and 300nm respectively.The microspheres are suitable for thefuel container of ICF targets.