Wang Jianji

Thermodynamic parameters of the interaction of CsCl with monosaccharide (d-glucose, d-galactose, d-xylose, and d-arabinose) in water at

Abstract A non-liquid-junction electrochemical cell composed of a potassium ion selective electrode(K-ISE) against a chloride ion selective electrode (Cl-ISE) as a reference electrode was employed to study the thermodynamic parameters of weak interactions between aqueous cesium chloride and the monosaccharides ( d -glucose, d -galactose, d -xylose, and d -arabinose) at T=298.15 K . Activity coefficients for this system obtained from electromotive force measurements indicate that they have a close relationship with the stereostructure of the saccharide. The Gibbs free energy pair interaction parameters and salting constants were also evaluated; these can characterize the interaction between the saccharides and CsCl in water. The results were interpreted on the basis of a model of structural and electrostatic interaction and the hydration effect of the hydroxyl ion of these saccharides.

Molecularly imprinted SPE coupled with HPLC for the selective separation and enrichment of alkyl imidazolium ionic liquids in environmental water samples

A novel 1-butyl-3-methylimidazolium chloride ionic liquid surface imprinted solid-phase sorbent was synthesized. The as-prepared material was characterized by SEM, Brunauer-Emmett-Teller surface area analysis and Fourier Transform IR measurements. Then its adsorption properties for alkyl imidazolium ionic liquids, including adsorption capacities, adsorption kinetics, and properties of selective separation and enrichment were studied in detail. It was shown that the ionic liquid surface imprinted polymer exhibited high selective recognition characteristics for the imidazolium chloride ionic liquids with short alkyl chains (C(n)mimCl, n = 2, 4, 6, 8) and the adsorption equilibrium was achieved within 25 min. Various parameters were optimized for the 1-butyl-3-methylimidazolium chloride ionic liquid surface imprinted polymer SPE column, such as flow rate, eluent solvent, selectivity, and reusability of the column. Then, the SPE column coupled with HPLC was used for the determination of alkyl imidazolium ionic liquids. Experimental results showed that the existence of their structural analogs and common concomitants in environmental matrices did not affect the enrichment of 1-butyl-3-methyl imidazolium chloride ionic liquid. The average recoveries of 1-butyl-3-methylimidazolium chloride ionic liquid in spiked water samples were in the range of 92.0-102.0% with the RSD lower than 5.8%.

Volumetric properties of glucose in aqueous HCl solutions at temperatures from 278.15 to 318.15 K

Densities have been measured for Glucose + HCl +Water at 10-degree intervals from 278.15 to 318.15 K. The apparent molar volumes (VΦ,G) and standard partial molar volumes (VΦ,G0) for Glucose in aqueous solution of 0.2, 0.4, 0.7, 1.1, 1.6, 2.1 mol·kg−1 HCl have been calculated as well as volumetric interaction parameters (VEG) for Glucose — HCl in water and standard partial molar expansion coefficients (∂VΦ,G0 / ∂T)p. Results show that (1) the apparent molar volume for Glucose in aqueous HCl solutions increases lineally with increasing molality of Glucose and HCl; (2) VΦ,G/0 for Glucose in aqueous HCl solutions increases lineally with increasing molality of HCl; (3) the volumetric interaction parameters for Glucose — HCl pair in water are small positive and vary slightly with temperature; (4) the relation between VΦ,G0 and temperature exists as VΦ,G0 = a0 + a1(T − 273.15 K)2/3; (5) values of (∂VΦ,G0 / ∂T)p are positive and increase as temperatures rise, and at given temperatures decrease slightly with increasing molalities of HCl, indicating that the hydration of glucose decreases with increasing temperature and molality of HCl. These phenomena are interpreted successfully by the structure interaction model.

Density Functional Study of Cationic and Anionic AgmCun (m + n ≤ 5) Clusters

The structural and energetic properties of bimetallic AgmCun clusters (m + n ≤ 5) in the cationic and anionic charged states have been investigated by density functional theory with relativistic effective core potentails. The stable cationic pentamers have three-dimensional structures in contrast to anionic clusters assume planar structures. For the given cluster size the electron affinities decrease as the Cu content increases, while no clear trend can be found in adiabatic ionization potentials. The binding energy per atom also increases with the increasing Cu content and follows the order anion < cation. The most probable dissociation channels of the clusters considered are also discussed.

The research progress in the recovery of ionic liquids by using ionic liquid-based aqueous two-phase systems

The investigation on the separation and recovery of ionic liquids from water would be of great importance in reducing environmental impact of ionic liquids, enhancing their utilization efficiency, decreasing their industrial cost and promoting their industrial application. In this review, we focused our attention on the research progress in the recovery of ionic liquids by using salt + ionic liquid aqueous two-phase systems, sugar + ionic liquid aqueous two-phase systems, polymer + ionic liquid aqueous two-phase systems, and carbon dioxide induced aqueous two-phase systems. The main influence factors on the recovery of the ionic liquids were analyzed, and advantages and disadvantages of different ionic liquid aqueous two-phase systems were evaluated. The development in the ionic liquid recovery was prospected and the challenges were stressed.