Study On Mutual Solubility And Electrochemical Properties Of Two Tpyes Of 1-Alkyl-3-methylimidazolium-based Ionic Liquids With Fatty Alcohols

Room-temperature ionic liquids as a new type of green liquid solvent material was viewed as the most promising green solvents after water and supercritical fluid, broadly applied in many field of chemical industry. Imidazolium-based Ionic Liquids with Fatty Alcohols are most commom binary system containing ionic liquids. Mutual solubility and electrochemical properties of ionic liquids with fatty alcohols are important foundation database for its application.In this paper a series of ILs were synthesized by two-step method and identified by H1-NMR, These ILs were BmimBF4, PmimBF4, HemimBF4, HepmimBF4,OmimBF4, BmimPF6, PmimPF6, HemimPF6, HepmimPF6 and OmimPF6. The Purity of these ionic liquids were also measured though the HPLC; the yield of RmimX, RmimBF4 and RmimPF6 with different alkyl chain length were compared, the influence of synthesis temperature were also studied. The synthesis yield increased with ionic liquids alkyl chain length. Higher temperature lead to a higher yield, however also lead to a darker color of ionic liquids; The liquid-liquid equilibria data of RmimBF4/PF6 with alcohols were measured by Changing Temperature Method, liquid-liquid equilibria diagrams were depicted, the UCSTs and the corresponding concentrations of the ionic liquids were find as well, then the liquid-liquid equilibria data of the both two phase were interpolated using a polynormial function, furthermore the experimental liquid-liquid equilibria data were correlated using the NRTL model for excess Gibbs energy, the overall-average deviations(AAD) ranged from 1.27% to 17.05%, the average value was 6.8%; the electrochemical window of ionic liquids in alcohols were measured, the ionic liquids in alcohols were 1mol/L,0.5mol/L,0.2 mol/L and 0.1mol/L BmimBF4 in ethanol,0.2mol/L BmimBF4 in ethanol, 1-propanol,1-butanol,1-pentanol,1-hexanol,0.2mol/L PmimBF4 in ethanol and 0.2mol/L OmimBF4 in ethanol. The widest electrochemical window of these ionic liquids in alcohols reached 3.35V, widened in pace with the concentrations reduction of ionic liquids in alcohols, and growth of alcohols alkyl chain length, and the change of ionic liquids alkyl chain length barely affected the electrochemical window of ionic liquids in alcohols.