RT info:eu-repo/semantics/article
T1 Melting point depression effect with CO2 in high melting temperature cellulose dissolving ionic liquids. Modeling with group contribution equation of state
A1 Lopes, Joana
A1 Sánchez, Francisco A.
A1 Rodríguez Reartes, Sabrina Belén
A1 Bermejo Roda, Maria Dolores
A1 Martín Martínez, Ángel
A1 Cocero Alonso, María José
K1 propiedades térmicas
K1 Thermal properties
K1 Ionic liquid
K1 Carbon dioxide
K1 Melting point depression
K1 Imidazolium chlride
K1 Group contribution
AB Ionic liquids of the alkylmethylimidazolium chloride family are able to solubilize high amount of cellulose and other natural polymers and have very good characteristics for their processing. Nevertheless, they present important disadvantages related to their high melting points and viscosities. Dissolution of carbon dioxide (CO2) can reduce the melting point of these ionic liquids as well as other ones presenting the same problems. In this work, the effect of pressurized carbon dioxide on the melting point depression of some ionic liquids able to dissolve biopolymers was experimentally determined using the first melting point method. Five different ionic liquids were studied in contact with CO2 using a high-pressure visual cell, up to a pressure of 10 MPa. The ILs studied were four ionic liquids with chloride anion coupled with the cations: 1-butyl-3-methylimidazolium, [C4mim]+, 1-ethyl-3-methylimidazolium, [C2mim]+, 1-allyl-3-methylimidazolium, [Amim]+ and 1-(2-hydroxyethyl)-3-methylimidazolium, [C2OHmim]+ and one ammonium-based cation choline [C5H14NO]+ combined with dihydrogen phosphate anion, [H2PO4]−. Melting point depression effect observed for these groups of ionic liquids were around 10 K for chloride ILs and went as high as 33.2 K for choline dihydrogen phosphate. To correlate the melting point depression of imidazolium chloride ILs, parameters for the Group Contribution Equation of State (GC-EoS) of Skjold-Jørgensen for the liquid phase plus a fugacity expression for solid phases was employed. Experimental data used for the parameterization includes literature data of binary vapor–liquid, liquid–liquid and solid–liquid equilibria, and activity coefficients at infinite dilution. Melting point depression was calculated with an average deviation of 1.7 K (0.5%) and a maximum deviation of 4.3 K (1.3%).
PB Elsevier B.V.
SN 0896-8446
YR 2016
FD 2016
LK http://uvadoc.uva.es/handle/10324/26140
UL http://uvadoc.uva.es/handle/10324/26140
LA eng
NO The Journal of Supercritical Fluids Volume 107, January 2016, Pages 590-604
NO Producción Científica
DS UVaDOC
RD 23-dic-2024