摘要
超临界流体快速膨胀法 (RESS)是一项近 10年发展起来的制备超细微粒的新技术。它将溶解有饱和溶质的超临界流体在非常短的时间内 (10 -8～ 10 -5s)通过一个喷嘴 (2 5～ 6 0μm)进行减压膨胀 ,利用强烈的机械扰动以达到极高的过饱和度 (约 10 6)和均相成核条件 ,从而产生纳米至微米级粒径且粒径及形态分布均匀的超细微粒。该方法已经在制备药物微粒、聚合物微粒和纤维、有机材料和无机材料与陶瓷先驱物等方面得到广泛的应用研究 ,不仅可以制备单组分的形态不同的微粒或纤维 ,还可以制备双组分的包覆型微粒。但理论研究目前还处于探索阶段 ,不能准确解释装置结构参数和操作条件对最终产物形态的影响。在此主要就超临界流体的性质 ,RESS方法的基本原理、理论和应用研究成果进行简单介绍。
The rapid expansion of supercritical solutions (RESS) is a novel technique preparing microparticles, which has developed recently 10 years. It causes the supercritical solutions saturated with solute depressurizedly to expand through a capillary nozzle (25～60 um) within an extremely short time (10 -8 ～10 -5 s). Because of the very high supersaturation (about 10 6) and homogeneous nucleation condition engendered by the mechanical perturbations, the RESS process produces microparticles which range from nanometer to micron and have narrow particle size and morphology distribution. This technique has been fully used to prepare the pharmaceutical microparticles, polymeric microparticles and fibers, organic materials, inorganic materials and microparticles of the ceramic precursor. It not only produces microparticles and fibers of the single solute, but also produces the microcapsules of two solutes. But an understanding of the underlying theory is still at an early stage, thus the relations between the morphology of the products and the operational and structural parameters cannot be explained accurately. A brief review of the supercritical fluid properties, fundamental principle and theoretical investigations and application researches for the RESS process was given in more detail in this paper.
出处
《化学反应工程与工艺》
CAS
CSCD
北大核心
2002年第4期344-352,共9页
Chemical Reaction Engineering and Technology
