dc.description.abstract | This thesis is divided into two parts. The first part is the solid solubility data of 15 pharmaceutical compounds in supercritical carbon dioxide Under different temperatures and pressures, the infinite dilution activity coefficient for pharmaceutical compound is described by regular solution model associated with the
Flory-Huggins equation.While correlating the data, the molarvolume of the solid solute is considered as a variable consisting of two parameters for the model. This volume is then transformed into a reduced form by introducing the critical density of carbon dioxide and even simplified to be with only one parameter involved. Comparing the correlation results obtained from the commonly used semi-empirical models of Mendez-Santigo-Teja and Chrastil. It is observed that regular solution model calculated with the Flory-Huggins equation of 15 pharmaceutical compounds in supercritical carbon dioxide solubility data, a total of 412 data points and obtained quite satisfactory results. In addition, a further consideration that the only parameter included in the present model could be expressed in terms of the ratio of the molecular weight of compound to that of CO2, and makes the model become a more
general and could be applied for prediction.
The second part of the solubility measurements of gasohol, the liquid-liquid equilibria of the mixtures consisted of ethanol, water, and the main components of gasoline fuel: pentane, hexane, and cyclohexane were experimentally determined. This study is related to the phase behavior when water in atmosphere is absorbed into ethanol + gasoline fuel (gasohol) and then possibly separates into two liquid phases in an automobile fuel tank or an underground storage tank. The liquid-liquid equilibria in this study include three ternary systems: ethanol + water + pentane, ethanol + water + hexane, and ethanol + water + cyclohexane; three quaternary systems: ethanol + water + pentane + hexane, ethanol + water + pentane + cyclohexane, and ethanol + water +hexane + cyclohexane; one quinary system: ethanol + water + pentane + hexane + cyclohexane. The present experiments were conducted at 293.15, 303.15, and 308.15 K, and the experimental data were collected and some were compared to that available in literature, and finally all data were correlated with the UNIQUAC
activity coefficient model. | en_US |