Experimental Study on Solubility of Metal Oxides in Novel Deep Eutectic Solvents of Choline Chloride-Organic Acid

In this work, novel deep eutectic solventDeep eutectic solvent (DES) was prepared from the choline chlorideCholine Chloride as a hydrogenHydrogen-bond acceptor in combination with organic acidsOrganic Acid (i.e., phthalic acid, 2,2-dimethylol propionic acid, glutamic acid, tartaric acid) as a hydrogenHydrogen-bond donor. Only at the preparation temperature of 110 °C, two novel of DESs were prepared: choline chlorideCholine Chloride:2,2-dimethylol propionic acid with molar ratios of 1:0.67 and the choline chlorideCholine Chloride:tartaric acid at a 1:0.5 molar ratio. The thermal stability of DESs was studied. DESs choline chlorideCholine Chloride:2,2-dimethylol propionic acid (1:0.67) and choline chlorideCholine Chloride:tartaric acid (1:0.5) were found stable at temperatures lower than 211 and 195 °C respectively. The solubility of metal oxides (MOs) ZnO, Fe2O3, Fe3O4, and V2O5 was determined in choline chlorideCholine Chloride:2,2-dimethylol propionic acid (1:0.67) and choline chlorideCholine Chloride: tartaric acid (1:0.5). The obtained MOs solubility values indicated these novel DESs with the interesting ability to dissolve the selected MOs.