超临界流体快速膨胀用于细颗粒包覆技术  

A Novel Technology for Fine Particle Coating by Using Rapid Expansion of Supercritical Fluid Solution

作　　者：王亭杰[1] 堤敦司[2] 金涌[1] 

机构地区：[1]清华大学化工系,北京100084 [2]Department of chemical system Engineering,The University of Tokyo,Tokyo

出　　处：《化工进展》2000年第4期42-47,共6页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金资助项目!(No.29906004);高等学校博士学科点专项科研基金项目!(No.99000331)

摘　　要：研究超临界流体在快速膨胀过程中的热力学状态变化，超临界流体在喷嘴端部快速膨胀过程中温度急剧降低，在一定条件下，降低的温度与流体体积流率平方成线性关系。超临界流体在快速膨胀射流中产生数十纳米量级的微核颗粒，流体膨胀前温度对微核粒径有显著影响。通过超临界流体在流化床中的快速膨胀，使包覆剂微核在颗粒表面形成均匀的薄膜色覆，实现颗粒或颗粒中关键组分在溶剂中的控制释放。The change,of thermodynamic state of the superoritical fluid in the rapid expansion process through a narrow nozzle has been studied. The rapid expansion of the supercritical fluid result in a significant temperature drop of the fluid at the nozzle outlet. The experimental experimental results have shown that the temperature drop is a linear function of the square of the fluid volume flow rate at certain condition. The ultrafine particles at an older of tens nanometer form in the expansion flow. The pre-expansion temperature of the supercritical fluid affects the size of the ultrafine particles significantly. By using the rapid expansion of the supercritical fluid solution, a uniform film forms through the nucleus deposition on the core particle surface in a fluidized bed. The release rate of the particle or the key composition dried by the particle in a solvent can be controlled.

关 键 词：超临界流体 包覆 流化床 细颗粒 快速膨胀 

分 类 号：TQ067[化学工程] TB48[一般工业技术—包装工程]