A Study For The Interaction Between Gluconic Acid Lonic Liquids And Molecular Sovents

Gluconic acid ionic liquids （GAILs） are a new class of ionic liquids. Compared with traditional ionicliquids, they are excellently biodegrabale, and show potential value in practical applications. Without theirthe physical and chemical properties of ionic liquids, gluconic acid ionic liquids can’t be applied well inindustry. In this paper, a series of gluconic acid ionic liquids were synthesized, and the interaction betweenionic liquids and the molecular solvents were studied.These should provide some theoretical foundationsand basic data for further studying and industrtial application of this kind of ionic liquids. This work wassupported financially by the National Natural Science Foundation （No.20973055） and the InnovatorFoundation of the Colleges and Universities of Henan Province. The major contents and conclusions are asfollows:1. The7kinds of gluconic acid ionic liquids ([C_nmim][C₆H₁₁O₇], n=2,4,6,8,10,12,14) weresynthesized, they were first reported.Densities for them in water and organic solvents （methanol,n-propanol） were derermined at298.15K. Based on these data, the apparent molar volumes and limitingapparent molar volumes were calculated in solvents. The IL-molecular solvent interactions were discussedin terms of the properties of the solvens and the alkyl chain length of the cations of the ILs. It is shown that:1) limiting apparent molar volumes of the ionic liquids increase linearly with increasing alkyl chain lengthof the ILs in the same solvent;2) the limiting apparent molar volume values of the ionic liquids in water arelarger than the alcohols solutions.2. Viscosities of gluconic acid ionic liquids ([C_nmim][C₆H₁₁O₇], n=2,4,6,8,10,12,14) in water andorganic solvents （methanol, ethanol, n-propanol） were measured at298.15K. The viscosity B-coefficientsof the ILs were also calcucated. It was shown that the values of viscosity B-coefficients for ILs are affectedsignificantly by the properties of the solvents and the alkyl chain length of the cations of the ILs.1) in thesame solvent, the values of viscosity B-coefficients for ionic liquids increase with increasing alkyl chainlength of the ILs;2) in the different solvent, the values are in the order:B（water）<B（methanol）<B（ethanol）<B（n-propanol）.3. Conductivities of gluconic acid ionic liquids ([C_nmim][C₆H₁₁O₇], n=2,4,6,8,10,12,14) in waterand organic solvents （methanol, ethanol, n-propanol） were precisely measured at298.15K. The values of the limiting molar conductivities （Λ⁰m） and the association constants （KA） for these ionic liquids werecalculated. The limiting molar conductivities of gluconic acid ILs were discussed as a function of theproperties of the solvents and the alkyl chain length of the cation. The results indicated that:1) the valuesof Λm⁰decrease with increasing the chain length in the same sovlent; the values of KAincrease withincreasing chain length in water, and decrease in the alcoholic solutions.2) in the different solvents, thevalues of Λ⁰mare in the order: Λ⁰m（methanol）> Λ0m（water）> Λ0m（ethanol）> Λ0m（n-propanol）, and thevalues of KAare in the order: KA（water）<KA（methanol）<KA（ethanol）<KA（n-propanol）.4. The aggregation behavior of [Cnmim][C₆H₁₁O₇], n=8,10,12,14) was investigated in aqueoussolutions by conductivity. The critical aggregation concentration （CAC）, ionization degree of theaggregates （α） and the standard Gibbs energy of aggregation （ΔG⁰m） were derived from the experimentaldata. The aggregation behavior of ionic liquids was also analyzed as a fuction of the alkyl chain length ofthe cation. The alkyl chain length of cation can be tailored to switch the aggregation behavior of ILs.5. Densities and viscosities for the geminal dicationic ionic liquids (GDILs,[Cn（mim）2]Br2and[Cn（mim）2][C₆H₁₁O₇]2（n=4,5,6）)+water systems were measured at298.15K. Limiting apparent molarvolumes （V0Φ,IL） and viscosity B-coefficients were evaluated for the ILs in aqueous solutions. It wasdiscussed that the effects of the alkyl linkage chain lengths of ionic liquids and the size of the differentantions on the volmmetric and viscosity properties for the ILs. The results indicated that the limitingapparent molar volumes （V0） and viscosity B-coefficients for all the ILs increase with increasing alkyl...