Solubility of CO2-philic polyhedral oligomeric silsesquioxanes in supercritical carbon dioxide

Demirtaş, Cansu
Polyhedral oligomeric silsesquioxanes (POSS) with different functional groups and carbon dioxide (CO2) binary systems’ phase behavior have been studied in a high- pressure visible cell to contribute to the development of environmentally friendly processes of POSS with supercritical carbon dioxide. POSS can show different hybrid material properties due to its functional groups attached to its cage structure. Supercritical carbon dioxide, which is referred as an environmentally friendly solvent, can exhibit specific interactions such as Lewis acid-base interactions or weak hydrogen bonding due to its quadrupole moment, and form single phase solutions with various materials. The studied POSS structures, which can form homogenous solutions with CO2, include octatrimethylsiloxy, methacryl, isooctyl, octaisobutyl, and trifluoropropyl POSS. Octatrimethylsiloxy POSS-CO2 system has been studied for the first time, while the other POSS-CO2 phase behavior studies have been conducted at different temperature ranges than those studied previously. Experimental data have been correlated using semi-empirical density-based models which are Mendez-Santiago and Teja (MST), Chrastil, Bartle, Chrastil Modified Wang (C-W), del Valle and Aguilera (del Valle) and Kumar and Johnston (K-J).


Phase equilibria of binary systems with carbon dioxide and carbon dioxide-philic materials
Dumanlılar, Beril.; Dilek Hacıhabiboğlu, Çerağ; Department of Chemical Engineering (2019)
Phase behavior investigations in supercritical carbon dioxide (scCO2) permit design and development of new and environmentally friendly supercritical fluid processes. Recently polyhedral oligomeric silsesquioxanes (POSS) modified with certain functional groups have been found to be soluble in supercritical CO2. In this thesis, solubilities of methacrylisobutyl POSS (MIBPOSS) and methacrylisooctyl POSS (MIOPOSS) in scCO2 have been studied. In the structure of these molecules, one of the eight branched alkyl ...
Activated carbon-supported CuO nanoparticles: a hybrid material for carbon dioxide adsorption
Boruban, Cansu; Nalbant Esentürk, Emren (Springer Science and Business Media LLC, 2018-02-28)
Activated carbon-supported copper(II) oxide (CuO) nanoparticles were synthesized by simple impregnation method to improve carbon dioxide (CO2) adsorption capacity of the support. The structural and chemical properties of the hybrid material were characterized by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction (XRD), Xray photoelectron spectroscopy (XPS), atomic absorption spectroscopy (AAS), and Brunauer-Emmett-Teller (BET) analyses. The analyses showed that CuO nanopart...
Mass transfer modeling of apricot kernel oil extraction with supercritical carbon dioxide
Ozkal, SG; Yener, Meryem Esra; Bayindirli, L (2005-09-01)
Effects of process parameters on extraction of apricot (Prunus armeniaca L.) kernel oil with supercritical carbon dioxide (SC-CO2) were investigated. The parameters included particle size (mean particle diameter < 0.425-1.5 mm), solvent flow rate (1-5 g/min), pressure (300-600 bar), temperature (40-70 degrees C) and co-solvent concentration (up to 3.0 wt.% ethanol). The model of broken and intact cells represented the apricot kernel oil extraction well. Grinding was necessary to release the oil from intact ...
Chemistry, Temperature, and Faunal Distributions at Diffuse-Flow Hydrothermal Vents Comparison of Two Geologically Distinct Ridge Systems
Luther, George W.; Gartman, Amy; Yücel, Mustafa; Madison, Andrew S.; Moore, Tommy S.; Nees, Heather A.; Nuzzio, Donald B.; SEN, Arunima; Lutz, Richard A.; Shank, Timothy M.; Fisher, Charles R. (2012-03-01)
Diffuse-flow, low-temperature areas near hydrothermal vents support life via chemosynthesis: hydrogen sulfide (and other reduced chemical compounds) emanating from the subsurface is oxidized with bottom-water oxygen through bacterial mediation to fix carbon dioxide and produce biomass. This article reviews the in situ diffuse-flow chemistry (mainly H2S and O-2) and temperature data collected in 2006 and 2009 along the Eastern Lau Spreading Center (ELSC), and from 2004 to 2008 at 9 degrees N along the East P...
Phase Equilibria of Binary Systems with CO2 and Bifunctional Polyhedral Oligomeric Silsesquioxanes
Dumanlılar, Beril; Dilek Hacıhabiboğlu, Çerağ (2018-09-01)
Solubility and phase behavior investigations of novel materials in supercritical carbon dioxide (scCO2) permit design and advancement of new and environmentally friendly supercritical fluid processes. Supercritical carbon dioxide (scCO2) is called as a green solvent because it is non-toxic, non-flammable, inexpensive, and abundant. Its use in a process instead of an organic solvent can eliminate the emissions of volatile organic components. Also, due to its nonpolar structure,it can dissolve nonpolar molecu...
Citation Formats
C. Demirtaş, “Solubility of CO2-philic polyhedral oligomeric silsesquioxanes in supercritical carbon dioxide,” Thesis (M.S.) -- Graduate School of Natural and Applied Sciences. Chemical Engineering., Middle East Technical University, 2019.