{"title":"High-pressure phase behavior of the carbon dioxide-trifluoropropylisobutyl polyhedral oligomeric silsesquioxane binary system","authors":"Alican Ertas, Cerag Dilek","doi":"10.1016/j.supflu.2025.106538","DOIUrl":null,"url":null,"abstract":"<div><div>The solubility of a bifunctional polyhedral oligomeric silsesquioxane, trifluoropropylisobutyl (TFIB) POSS, in supercritical carbon dioxide (scCO<sub>2</sub>) was investigated. In the temperature and pressure ranges of 308 K to 323 K and 8.8 MPa to 14.5 MPa, respectively, TFIB POSS is soluble in scCO<sub>2</sub> up to 2.0 × 10<sup>−2</sup> by weight fraction corresponding to 1.0 × 10<sup>−3</sup> by mole fraction, which is between the solubility of its monofunctional counterparts, octaisobutyl POSS and octatrifluoropropyl POSS. The study includes the modeling of the TFIB POSS-CO<sub>2</sub> binary system phase equilibrium with the density-based semi-empirical equations and Peng Robinson+COSMO segment activity coefficient (PR+COSMOSAC) equation of state (EOS). The prediction of the equation of state has been improved for the cage-structured molecule by introducing new electrostatic and dispersion contributions. While the density-based relations provide better fits to the solubility isotherms, the main advantage of the EOS is its applicability for a priori phase equilibrium predictions for the CO<sub>2</sub>-POSS systems in the absence of the solute critical properties.</div></div>","PeriodicalId":17078,"journal":{"name":"Journal of Supercritical Fluids","volume":"219 ","pages":"Article 106538"},"PeriodicalIF":3.4000,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Supercritical Fluids","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0896844625000245","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
The solubility of a bifunctional polyhedral oligomeric silsesquioxane, trifluoropropylisobutyl (TFIB) POSS, in supercritical carbon dioxide (scCO2) was investigated. In the temperature and pressure ranges of 308 K to 323 K and 8.8 MPa to 14.5 MPa, respectively, TFIB POSS is soluble in scCO2 up to 2.0 × 10−2 by weight fraction corresponding to 1.0 × 10−3 by mole fraction, which is between the solubility of its monofunctional counterparts, octaisobutyl POSS and octatrifluoropropyl POSS. The study includes the modeling of the TFIB POSS-CO2 binary system phase equilibrium with the density-based semi-empirical equations and Peng Robinson+COSMO segment activity coefficient (PR+COSMOSAC) equation of state (EOS). The prediction of the equation of state has been improved for the cage-structured molecule by introducing new electrostatic and dispersion contributions. While the density-based relations provide better fits to the solubility isotherms, the main advantage of the EOS is its applicability for a priori phase equilibrium predictions for the CO2-POSS systems in the absence of the solute critical properties.
期刊介绍:
The Journal of Supercritical Fluids is an international journal devoted to the fundamental and applied aspects of supercritical fluids and processes. Its aim is to provide a focused platform for academic and industrial researchers to report their findings and to have ready access to the advances in this rapidly growing field. Its coverage is multidisciplinary and includes both basic and applied topics.
Thermodynamics and phase equilibria, reaction kinetics and rate processes, thermal and transport properties, and all topics related to processing such as separations (extraction, fractionation, purification, chromatography) nucleation and impregnation are within the scope. Accounts of specific engineering applications such as those encountered in food, fuel, natural products, minerals, pharmaceuticals and polymer industries are included. Topics related to high pressure equipment design, analytical techniques, sensors, and process control methodologies are also within the scope of the journal.