JOURNAL OF MOLECULAR LIQUIDS
·
2020
·
IF 5.065
Xiaojie Liu,Chunying Zhu,Taotao Fu,Youguang Ma
The densities and viscosities of ternary solution of piperazine (PZ) + 2-Amino-2-methyl-1-propanol (AMP) + H 2 O were measured at P = 101 kPa and T = (303.15–343.15) K. The effects of temperature and concentration on the density and viscosity of ternary solution were investigated. The apparent molar volume ( V φ ), the limiting partial molar volume ( V φ 0 ), viscosity B -coefficient, Helper's constant and the free energies of activation per mole of solvent ( Δμ 1 0≠ ) and solute ( Δμ 2 0≠ ) were calculated from the density and viscosity, respectively. The solute-solute and solvent-solute interactions were analyzed from the volumetric and viscometric properties. The results show that the PZ has a destructive effect on the structure of mixed solvent.
研究领域:
物理化学
·
溶液化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2021
·
IF 6.165
Yushi Guo,Ling Wu,Chenglin Jiang,Jinling Zhao,Lutian Feng,Kaiyue Zhang,Ye Qin,Xiangrong Li,Jianguo Liu,Chuanwei Yan,Jiazhen Yang,Na Wang,Duo Qi,Junyao Li,Ming Lei
A number of additives have been proven to improve the performance of vanadium redox flow batteries (VRFBs). Polyacrylic acid (PAA) is considered to be one of the promising candidates because of its beneficial effects on the stability of batteries . This paper studied the influence of PAA on viscosity, which is one of the electrolyte transport properties. The viscosity of VOSO 4 + PAA + H 2 O ternary solution was measured at different temperature, ionic strength , and ionic strength fractions in the temperature range of 283.15 K–318.15 K. Several thermodynamic parameters of the PAA aqueous solution were calculated, such as the viscosity B -coefficients, the apparent molar volume of infinite dilution and the free energy of activation . In addition, two different semi-empirical prediction equations were established for ternary solution viscosity on the basis of the Eyring's theory , and the better one was determined through comparison. The average relative deviation is 0.74% between the predicted and the experimental values, which indicates this function can be used to predict the viscosity of VOSO 4 + PAA + H 2 O ternary solution.
研究领域:
电化学
·
物理化学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2022
·
IF 3.119
Lehui Tu,Yunlong Shi,Chunying Zhu,Taotao Fu,Xiqun Gao,Youguang Ma
Densities and viscosities of sugar alcohols (meso-erythritol, xylitol, and d-sorbitol) in glycylglycine–water mixtures were measured at T = (293.15, 303.15, 313.15, 323.15, and 333.15) K under atmospheric pressure. Furthermore, the apparent molar volume, the limiting partial molar volume, the limiting partial molar volume of transfer, the viscosity B coefficient, and the free energies of activation per mole of solvent and solute were obtained through the experimental data. Moreover, the limiting partial molar volume of transfer was analyzed based on the co-sphere overlap model, and the transition-state theory was applied to determine the active free energies. The results indicate that the ion–hydrophilic interaction between the sugar alcohols and glycylglycine molecules occupies a dominant position in the solution, d-sorbitol tends to act as a structural breaker in the glycylglycine–water mixtures, and meso-erythritol and xylitol tend to act as structural makers in the glycylglycine–water mixtures.
研究领域:
物理化学
·
溶液化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2015
·
IF 2.679
Xiaofen Ren,Chunying Zhu,Youguang Ma
Densities ( ρ ) and viscosities ( η ) of glycine, l -alanine, l -valine, l -threonine and l -arginine in (0.2, 0.4, 0.6, 0.8 and 1.0) mol · kg −1 aqueous sorbitol solutions have been measured at T = (293.15, 303.15, 313.15 and 323.15) K under atmospheric pressure. The apparent molar volume ( V φ ) and the limiting partial molar volumes of amino acids ( V φ 0 ) were calculated through the density data. And the limiting partial molar volumes of transfer (Δ tr V φ 0 ) and interaction coefficients V ab , and V abb were also determined. The extended Jones–Dole equation was used to correlate the viscosities in order to obtain viscosity B -coefficient and the free energies of activation per mole of solvent (Δ μ 1 0≠ ) and solute (Δ μ 2 0≠ ). The limiting partial molar volume of transfer and the free energies of activation per mole of both solvent (Δ μ 1 0≠ ) and solute (Δ μ 2 0≠ ) were discussed on the basis of the co-sphere overlap model and transition state theory, respectively. The hydration number of amino acids was computed using the obtained limiting partial molar volume and viscosity B -coefficient. Additionally, the group contribution method was applied to determine the respective contribution of (NH 3 + , COO − ), CH 2 , OH and CNHNHNH 2 to V φ 0 and B -coefficient.
研究领域:
物理化学
·
溶液化学
·
热力学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2023
·
IF 11.4
Yingying Zhou,Jia-jia Jiao,Huang Huang,Yong Dong Liu,Rugang Zhong,Xin Yang
Dichloroacetonitrile (DCAN) as one of the potentially prioritized regulated DBPs has drawn great attention; however, understanding its formation, especially the C–C bond cleavage mechanisms, is limited. In this study, DCAN formation mechanisms from long-chain primary amines, amino acids, and dipeptides during chlorination were investigated by a combined computational and experimental approach. The results indicate that nitriles initially generate for all of the above precursors, then they undergo β-C-hydroxylation or/and α-C-chlorination processes, and finally, DCAN is produced through the Cα–Cβ bond cleavage. For the first time, the underlying mechanism of the C–C bond cleavage was unraveled to be electron transfer from the O– anion into its attached C atom in the chlorinated nitriles, leading to the strongly polarized Cα–Cβ bond heterocleavage and DCAN– formation. Moreover, DCAN molar yields of precursors studied in the present work were found to be determined by their groups at the γ-site of the amino group, where the carbonyl group including −CO2–, −COR, and −CONHR, the aromatic group, and the −OH group can all dramatically facilitate DCAN formation by skipping over or promoting the time-consuming β-C-hydroxylation process and featuring relatively lower activation free energies in the C–C bond cleavage. Importantly, 4-amino-2-hydroxybutyric acid was revealed to possess the highest DCAN yield among all the known aliphatic long-chain precursors to date during chlorination. Additionally, enonitriles, (chloro-)isocyanates, and nitriles can be generated during DCAN formation and should be of concern due to their high toxicities.
研究领域:
环境化学
·
水处理
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2017
·
IF 3.648
Jing Zhang,Taotao Fu,Chunying Zhu,Youguang Ma
Densities and viscosities of glycine, L-alanine, L-valine, L-threonine and L-arginine in aqueous (0.1–0.5) mol·kg − 1 myo -inositol solutions were measured at T = (293.15, 303.15, 313.15 and 323.15) K and p = 0.101 MPa. The volumetric properties such as the apparent molar volume ( V φ ), the limiting partial molar volume ( V φ 0 ), the limiting partial molar volumes of transfer (Δ tr V φ 0 ), the limiting apparent molar expansibility ( E 2 0 ), Hepler's constant and the isobaric thermal expansion coefficient ( α 2 ) were calculated through density. The viscometric properties such as the B -coefficient, the free energies of activation per mole of solvent (Δ μ 1 0 ≠ ) and solute (Δ μ 2 0 ≠ ) were obtained from the experimental viscosity data. The derived parameters hydration number and solvation number were also calculated through apparent molar volume and B -coefficient. From the volumetric and viscometric properties, the solute-solute and solute-solvent interactions in the studied systems were analyzed on the basis of co-sphere overlap model and transition state theory . Finally, the group contribution method was applied to calculate the contribution of (NH 3 + , COO − ), CH 2 , OH and CNHNHNH 2 of amino acids to V φ 0 , B -coefficient and Δ μ 2 0 ≠ .
研究领域:
物理化学
·
热力学
·
溶液化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2018
·
IF 2.011
Feng Su,Ziqing Sun,Weike Su,Xianrui Liang
The tautomerism of three benzimidazole compounds: Omeprazole sulfide, 1 , (R)-Lansoprazole, 2 , and Omeprazole sulfone , 3 were investigated by NMR with the effect of variant solvents and temperature. The dielectric constant of the medium and the ability of solvents to form hydrogen bond with the tautomer had a profound effect on the tautomeric equilibration. The chemical shifts and resonance lines of compounds 1–3 differed greatly in different solvent system mainly due to intra- and intermolecular hydrogen bonds. Variable temperature-nuclear magnetic resonance (VT-NMR) experiments showed that at 203 K the two tautomers of compound 1 were separated and determined to be 6:4 and those of compound 3 be 7:3. In contrast, compound 2 presented only one tautomer at the same temperature while the tautomerism was observed again with temperature increasing. The free energy of activation of the tautomeric interchange of compounds 1 – 3 were 13.77 kcal/mol, 13.47 kcal/mol and 13.06 kcal/mol, respectively. Density function theory (DFT) calculations results showed the tautomers of compound 2 had higher energy differences among the three compounds demonstrating only one preferred conformation existed at 203 K. The preferred conformations of compounds 1 and 3 were also given.
研究领域:
化学
·
物理化学
·
光谱学
·
理论化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）