Thermodynamic Analysis of Micronization Processes from Gas-Saturated Solution

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• 作者：Nicola Elvassore ; Marina Flaibani ; Alberto Bertucco ; and Paolo Caliceti
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2003
• 出版时间：November 12, 2003
• 年：2003
• 卷：42
• 期：23
• 页码：5924 - 5930
• 全文大小：88K
• 年卷期：v.42,no.23(November 12, 2003)
• ISSN：1520-5045

文摘

A thermodynamic analysis is developed to interpret the influence of temperature and pressurein the production of solid lipid nano- and microparticles by a high-pressure technique namedparticle from gas-saturated solution (PGSS). The pressure-temperature charts show threeregions above the P-T solid-liquid-fluid coexistence curve, from which sub-cooled solid, solid-liquid, or liquid products can be obtained. The relation between the initial and finalthermodynamic properties of the PGSS process were calculated by solving simultaneously theenergy balance and a proper equation of state. The expansion of high-pressure CO₂-lipidsaturated solution through the micrometric nozzle was represented by a transformation atconstant total enthalpy. To represent the equilibrium and thermodynamic behavior of CO₂-lipid systems the perturbed-hard-sphere-chain theory (PHSCT) was used. As examples, CO₂absorption isotherms in lipids and residual properties of high-pressure tristearin-CO₂ andtristearin-phosphatidylcoline-CO₂ systems were calculated. Enthalpy of fusion of puresubstances and formation enthalpy of microparticulate PGSS products were measured bydifferential scanning calorimetry (DSC). Pure lipid EOS parameters were estimated by a groupcontribution method, whereas the equation of state (EOS) interaction parameters were adjustedon the experimental melting point data under CO₂ pressure, measured in a high-pressurewindowed cell. Application of operative charts provides useful information in understandingthe influence of temperature and pressure on the final properties of lipid particles produced byPGSS.