Joana M. Lopes

TL;DR: The use of Ionic liquids (ILs) for production of cellulose derived polymers is thoroughly studied in this article, where a brief summary of the state of the art in cellulose derivatives production is presented.

TL;DR: In this paper, drug loading capacity was investigated by impregnating phytol as model compound into the cellulose aerogels, using supercritical CO2 at 100bar, 40°C and mass ratio of PHYTol per gram of aerogel 10:1.

Abstract: 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-Jorgensen 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%).

TL;DR: In this paper, the effect of viscosity reduction caused by solubilization of CO 2 is studied in order to improve the biomass processing in ionic liquids, where densities and viscosities of the pure ionic liquid 1-allyl-3methylimidazolium chloride and its mixtures with CO 2 up molar fractions of 0.25 and temperatures between 333 and 372 K have been experimentally determined.

TL;DR: In this article, the authors investigated the pretreatment efficacy of the ionoSolv pretreatment of Eucalyptus red grandis using the low-cost ionic liquid triethylammonium hydrogen sulfate ([N2220][HSO4]) in the presence of 20 wt% water at 10% solids loading.