用静态法测定氯唑沙宗在超临界C02中的溶解度,考察温度(308~328K)和压力(10~30MPa)对溶解度的影响,并用经验关联方程对其进行关联。研究结果表明:氯唑沙宗的溶解度可达到10~mol/mol,满足超临界流体快速膨胀(RESS)的实验要求;经验方程Chrastil及其修正式的关联效果比Mendez-Santiago-Teja方程好,特别是Adachi和Lu-Chrastil修正式,平均值绝对相关偏差(AARD)为O.0170。另外,通过超临界流体快速膨胀技术制备长度为0.5~5μm,宽度为0.1~1μm的氯唑沙宗棒状颗粒,体积为原料的1/20,甚至更小。实验证明,粒子的具体大小和形状与平衡温度(308~328K)、平衡压力(10~30MPa)、喷嘴温度(343~383K)、喷嘴直径(0.1~0.4mm)和喷射距离(10~30mm)等操作参数密切相关。因为这些操作参数影响着超临界流体的溶解度、过饱和度和扩散情况等,从而决定了晶核的形成和生长。
Solubility and rapid expansion of supercritical solution (RESS) process of chlorzoxazone in supercritical carbon dioxide (SC-CO2) were studied. The mole fraction solubility can be up to 10-5 mol/mol, measured with a static method. The effects of temperature and pressure on solubility were investigated at temperatures ranging from 308 to 328 K and pressures froml0 to 30 MPa. Then the experimental data of solubility were correlated with the Chrastil model, modified Chrastil models and Mendez-Santiago-Teja model. The correlated results show that Chrastil empirical model and its modified models have better correlation effects, especially for Adachi and Lu modified Chrastil model, which produce an average absolute relative deviation (AARD) of 0.017 0. RESS is applied to prepare chlorzoxazone particles at different extraction temperatures, extraction pressures, nozzle temperatures, nozzle diameters and spray distances. The short clavate particles with average length of 0.5-5 μm and diameter of 0.1-1 μm are obtained, and the exact sizes vary with the different experimental conditions. The aforementioned experimental parameters determine the solubility, supersaturation and diffusion of the supercritical fluids and thereby influence the formation and growth of the chlorzoxazone micro particles.