Impact of Co-solvents on Deep Eutectic Solvents: A Combined Spectroscopic and PCA Investigation
Disciplines
Analytical Chemistry | Environmental Chemistry
Abstract (300 words maximum)
Deep eutectic solvents (DESs) have emerged as promising alternative solvents for various application including extraction, biocatalysis, and drug delivery owing to their unique physicochemical properties. Moreover, these solvents are less nonvolatile, nonflammable, nontoxic, biodegradable, and environmentally friendly. Compared to one component solvents, DESs are bicomponent which are formed by mixing hydrogen bond donors (HBD) and hydrogen bond acceptor (HBA) at a certain composition that exhibit a very large melting point depression. Heating and mechanical agitation are required to form these solvents. Although these solvents demonstrate lot of promise, industrial applications are limited due to their inherent high viscosity. In this study, two choline chloride (ChCl) based DESs including ChCl:Urea and ChCl:Glycerol were synthesized by mixing 1:2 molar ratio in a covered beaker heated at 80°C with constant stirring of 700 rpm until the transparent liquid was formed. In addition, we investigated the impact of water and methanol on the structure and interaction of pure DESs. The synthesis of the DESs were confirmed by IR spectroscopy. In ChCl:Urea DES, the stretching peak related to C=O group of urea was significantly broaden. Similar trend was also noticed for OH stretching. However, CH and OH stretching peaks in ChCl:Glycerol were shortened from the CH and OH stretching of glycerol. Both the Raman and PCA results showed that 1-5% cosolvents showed little impact on the component of DES, while 10-50% cosolvents significantly altered the structure and interaction of the DES components. Particularly in ChCl:Glycerol DES, the impact of water was random while the impact of menthol was consistent indicating that 30-50% cosolvents may break the pure DES interactions.
Academic department under which the project should be listed
CSM - Chemistry and Biochemistry
Primary Investigator (PI) Name
Mohammad A. Halim
Impact of Co-solvents on Deep Eutectic Solvents: A Combined Spectroscopic and PCA Investigation
Deep eutectic solvents (DESs) have emerged as promising alternative solvents for various application including extraction, biocatalysis, and drug delivery owing to their unique physicochemical properties. Moreover, these solvents are less nonvolatile, nonflammable, nontoxic, biodegradable, and environmentally friendly. Compared to one component solvents, DESs are bicomponent which are formed by mixing hydrogen bond donors (HBD) and hydrogen bond acceptor (HBA) at a certain composition that exhibit a very large melting point depression. Heating and mechanical agitation are required to form these solvents. Although these solvents demonstrate lot of promise, industrial applications are limited due to their inherent high viscosity. In this study, two choline chloride (ChCl) based DESs including ChCl:Urea and ChCl:Glycerol were synthesized by mixing 1:2 molar ratio in a covered beaker heated at 80°C with constant stirring of 700 rpm until the transparent liquid was formed. In addition, we investigated the impact of water and methanol on the structure and interaction of pure DESs. The synthesis of the DESs were confirmed by IR spectroscopy. In ChCl:Urea DES, the stretching peak related to C=O group of urea was significantly broaden. Similar trend was also noticed for OH stretching. However, CH and OH stretching peaks in ChCl:Glycerol were shortened from the CH and OH stretching of glycerol. Both the Raman and PCA results showed that 1-5% cosolvents showed little impact on the component of DES, while 10-50% cosolvents significantly altered the structure and interaction of the DES components. Particularly in ChCl:Glycerol DES, the impact of water was random while the impact of menthol was consistent indicating that 30-50% cosolvents may break the pure DES interactions.