JOURNAL OF CHEMICAL THERMODYNAMICS
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2018
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IF 2.631
Xiao Feng,Ali Farajtabar,Hu Lin,Gaoquan Chen,Zhiying Wang,Xinbao Li,Hongkun Zhao
The D-tryptophan solubility in aqueous solutions of methanol, ethanol, isopropanol and N , N -dimethylformamide (DMF) was measured by the saturation shake-flask method at temperatures ranging from 283.15 K to 333.15 K. The maximum solubility was found in water for alcohol (1) + water (2) mixtures, and in neat DMF for DMF (1) + water (2) mixture. When the same temperature and mass fraction of the water is given, the highest mole fraction solubility of D-tryptophan was found in (DMF + water). The solid phases were tested by X-ray powder diffraction (XPRD) showing no polymorphic transformation, solvate formation or crystal transition. Three solubility models, i.e. the Jouyban-Acree, van’t Hoff-Jouyban-Acree and Apelblat-Jouyban-Acree were employed to correlate the experimental solubility values so as to obtain thermodynamic parameters. The RAD and RMSD data were no more than 1.65% and 9.40 × 10 −5 , respectively. Linear solvation energy relationship analysis based on Kamlet-Taft parameters indicated that the variation of D-tryptophan solubility depended on π ∗ for methanol (ethanol, isopropanol) (1) + water (2), and cavity term for DMF (1) + water (2). The preferential solvation parameters ( δx 1,3 ) for methanol, ethanol, isopropanol and DMF derived by means of the inverse Kirkwood–Buff integrals were negative in the four solvent mixtures with intermediate and alcohol-rich compositions, which indicated that D-tryptophan was preferentially solvated by water. The higher solvation by water could be explained in terms of the higher acidic behaviour of the solvents interacting with the Lewis basic groups of the D-tryptophan. However D-tryptophan is preferentially solvated neither by water nor by DMF in DMF + water mixture.
研究领域:
化学
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生物学
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高影响因子
RSC Advances
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2018
·Vol. 8
·期 15
·7924-7931
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IF 2.936
Yanling Wang,Yongfei Li,Qian Wang,Qiang Li,Yue Zhang,Lin Yuan
The wettability of a rock’s surface is a vital factor for gas flow and fracturing fluid backflow. As a result of this, novel and effective gas wetting alteration agents are required. In this work, a gas-wetting alteration agent, N,N-bis(perfluorooctyl)imine acetate sodium, was synthesized and characterized by different methods. The wettability of a rock’s surface was evaluated by contact angle and imbibition measurements, the Owens two-liquid method and glass capillary tube rise testing. The results showed that after treatment with 0.5 wt% N,N-bis(perfluorooctyl)imine acetate sodium the contact angles of water and n-hexadecane on the surface of the rock increased from 36° and 0° to 140° and 119°, respectively. The surface free energy rapidly reduced from primeval 72 mN m−1 to 3.4 mN m−1 after treatment with 0.3 wt% N,N-bis(perfluorooctyl)imine acetate sodium. These values agreed with the imbibition measurements and the results of the glass capillary tube rise testing. Moreover, analysis by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) showed that the roughness of the rock surface significantly increased. The above results fully proved that the wettability of the rock surface is altered from its original water-wetting or oil-wetting to gas-wetting. Furthermore, thermal analysis demonstrated that the gas-wetting alteration agent has good thermal stability, which indicates its great potential to be used as a gas-wetting alteration agent for unconventional gas reservoirs under high temperature conditions.
研究领域:
石油工程
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材料科学
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DOI
高影响因子
Frontiers in Chemistry
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2021
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IF 5.221
Yang Xiaohui,Lu Wanlong,Cao Jingning,Zhai Chenyang,Li Weili,Zha Fangwen,Lu Guanghao,Tian Hongkun,Yu Demei,Bu Laju
The preparation of micron- to nanometer-sized functional materials with well-defined shapes and packing is a key process to their applications. There are many ways to control the crystal growth of organic semiconductors. Adding polymer additives has been proven a robust strategy to optimize semiconductor crystal structure and the corresponding optoelectronic properties. We have found that poly(3-hexylthiophene) (P3HT) can effectively regulate the crystallization behavior of N,N′-dioctyl perylene diimide (C8PDI). In this study, we combined P3HT and polyethylene glycol (PEG) to amphiphilic block copolymers and studied the crystallization modification effect of these block copolymers. It is found that the crystallization modification effect of the block copolymers is retained and gradually enhanced with P3HT content. The length of C8PDI crystals were well controlled from 2 to 0.4 μm, and the width from 210 to 35 nm. On the other hand, due to the water solubility of PEG block, crystalline PEG-b-P3HT/C8PDI micelles in water were successfully prepared, and this water phase colloid could be stable for more than 2 weeks, which provides a new way to prepare pollution-free aqueous organic semiconductor inks for printing electronic devices.
研究领域:
材料科学
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化学
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DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2023
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IF 6
Hui Liu,Jing He,Kun Zhu,Dongao Zhu,Linhua Zhu,Wenshuai Zhu,Huaming Li,Wei Jiang
Elaborate design of high stability catalytic active site is of great concern for the development of advanced organic–inorganic composite catalysts. Herein, cobalt-doped mesoporous molecular sieve grafted with N,N-dihydroxypyromellitimide catalyst (Co-SBA-15-NDHPI) is developed for the catalytic oxidative desulfurization (ODS) in diesel fuels. The close integration of organic active components and porous supports strengthens the synergistic catalytic effect, resulting enhancement of selective oxidation of sulfides to sulfone derivatives. In detail, N,N-dihydroxypyromellitimide is bonded to a Co-based mesoporous molecular sieve by 3-glycidyloxypropyltrimethoxysilane as the coupling agent allowing exclusive retention of NHPI, which serve as the active sites that result in boosted catalytic ODS performance. Meanwhile, taking advantage of strong chemical anchoring strategies, the Co-SBA-15-NDHPI catalyst exhibits the highest stability compared to other NHPI-containing desulfurization catalysts. This work opens the way for the development of a more stable organic–inorganic hybrid desulfurization catalyst.
研究领域:
催化化学
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材料科学
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DOI
高影响因子
Food & Function
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2023
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IF 6.1
Huili Jing,Meimei Nie,Xiaoqin Wang,Zhongyuan Zhang,Yayuan Xu,Guodong Zhang,Dajing Li,Zhuqing Dai
In this study, N-methyl-N nitrosourea (MNU)-induced retinitis pigmentosa (RP) model mice were used to investigate the protective effect of lutein (LUT) combined with epigallocatechin-3-gallate (EGCG) treatment. Compared to the LUT group, after the LUT combined with EGCG (LUT-EGCG) treatment, the accumulation content of LUT was significantly increased by 50.24% in the liver. The histopathological results showed that LUT-EGCG treatment significantly improved the structural damage of the retina and recovered the thickness of the outer nuclear layer of the retina to 185.28 ± 0.29 μm, which was no significant difference compared to the control group. The LUT-EGCG treatment also increased the production of short-chain fatty acids such as acetic and propionic acids. Compared with LUT individual treatment, the LUT-EGCG treatment significantly increased the relative abundance of Lachnospiraceae and Helicobacteraceae by Metastats analysis. RT-qPCR results showed that LUT-EGCG treatment significantly increased the antiapoptotic gene Bcl-2 expression. In addition, the expression level of IL-6 in the LUT-EGCG group was down-regulated significantly, but there was no significance in NF-κβ, TNF-α, IL-1β, and IL-18 compared with LUT treatment. Coupled with correlation analysis, results showed that LUT combined EGCG might protect against RP by regulating antiapoptotic gene expression and improving intestinal flora. These results provided helpful information for RP intervention.
研究领域:
眼科学
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药理学
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免疫学
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微生物学
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DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2023
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IF 2.6
Fan Yang,Qinqin Zhang,Hua Xin,Tianzhao Wu,Zhigang Zhang
Separating the mixture of the target product n-propyl acetate (NPAC) and the unreacted reactant n-propanol (NPA) is necessary during the production of NPAC. NPA and NPAC cannot be separated by simple distillation because the two could form an azeotrope under atmospheric pressure. Liquid–liquid extraction is an energy-saving and environment-friendly method for separating azeotropic mixtures. Ionic liquids (ILs) are promising alternatives to conventional extractants for separating azeotropes due to the advantages of designability and negligible vapor pressure. In this study, the liquid–liquid equilibrium (LLE) data for the ternary systems of NPAC + NPA + 1-butyl-3-methylimidazolium dihydrogen phosphate ([BMIM][H2PO4]) or 1-butyl-3-methylimidazolium thiocyanate ([BMIM][SCN]) or 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF4]) were determined at 303.15 K and 101.3 kPa. The accuracy of the experimental LLE data was checked by the Bachman, Hand, and Othmer–Tobias equations. The selectivity and partition coefficient were calculated to evaluate the extraction capability of the selected extractants. The experimental LLE data were correlated with the nonrandom two-liquid model, and the binary interaction parameters were regressed. Finally, the separation mechanism of the three ILs was explored through σ-profile analysis.
研究领域:
化学工程
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环境科学
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DOI
高影响因子
Systems Microbiology and Biomanufacturing
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2022
·Vol. 2
·期 3
·507-522
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IF 0
Du Juanjuan,Zhang Liang
N -methyl- d -aspartic acid (NMDA), an amino acid existing in human and animal central nervous system, exerts agonist action on one of the glutamate receptor subtypes and is clinically used for treatment of diabetes, Parkinson’s and Alzheimer’s syndrome. In this study, an enzymatic protocol for the chiral resolution of N -methyl- d , l -aspartic acid was built with a predicted N -demethylase (GenBank ID: OJV90073.1) from the genome of Chloroflexi bacterium 54-19. Through sequence alignment, the enzyme shares an identity of 32.19% to 2UZZ (PDB ID) with a conserved catalytic center. Recombinantly expressed in Bacillus subtilis WB600 , the N -demethylase was characterized with optimal temperature and pH at 55 ℃ and 7.5, and adaptive temperature and pH were 40–60 ℃ and 6–8. The effects of organic solvents and metal ions were investigated as well. Compared with other previously reported sarcosine oxidases, the enzyme showed a specific N -demethylation activity against N -methyl- l -aspartic acid according to the analysis by chiral liquid chromatography, LC–MS/MS and a detection by polarimeter. The results demonstrated 76% of 4.5 mM N -methyl- d , l -aspartic acid could be chirally separated by 7 mg·L −1 enzyme after reaction of 80 min. This work provided a foundation for mild synthesis of NMDA in industry. Graphical abstract
研究领域:
生物化学
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分子生物学
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微生物学
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药理学
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DOI
HIGH PERFORMANCE POLYMERS
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2015
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IF 1.286
Yewei Xu,Yi Sun,Yonglin Lei,Jichuan Huo,Lin Zhang
This article presents a convenient polymerization route to synthesize poly(arylene ether)s containing N-arylenebenzimidazolyl groups. The novel polymers were prepared by a catalyst-free nucleophilic substitution reaction, in which the N–H and O–H sites were removed from 2-(2-hydroxyphenyl)-1H-benzimidazole with different activated difluorides containing carbonyl groups in sulfolane. The reaction was carried out in the presence of anhydrous potassium carbonate at 210°C. The structures of the polymers were characterized using Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and elemental analysis. The results show good agreement with the proposed structure. All resulting polymers show essentially amorphous patterns. Moreover, differential scanning calorimetry and thermogravimetric measurements show that the polymers have high glass transition temperatures (>209°C), good thermostability, and high decomposition temperatures (>425°C). Furthermore, the polymers also exhibit excellent solubility in common organic solvents.
研究领域:
材料科学
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高分子化学
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DOI
高影响因子
POLYMER
·
2018
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IF 3.483
Qijing Chen,Fei Han,Chao Lin,Xuejun Wen,Peng Zhao
The aim of this study is to synthesize well-defined bioreducible core crosslinked star (CCS) polymers via heterogeneous reversible addition-fragmentation transfer (RAFT) polymerization in aqueous ethanol solutions. To this end, water-soluble linear arm polymers, poly (poly (ethylene glycol) methyl ether methacrylate) (PPEGMA), poly (2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and poly ( N , N -dimethylacrylamide) (PDMA), were prepared respectively. Next, heterogenous RAFT polymerization of the polymers with N , N ′-bis(acryloyl)cystamine (BAC) as a crosslinker was systemically investigated in an aqueous ethanol solvent. It was found that these bioreducible CCS polymers with crosslinked BAC core could be prepared successfully depending on polymerization parameters. The formation of PPEGMA-based CCS polymers was affected by water volume fraction ( V w ) of water-ethanol solution, reaction time, arm polymer concentration, and spacing monomer . Besides, at an optimal V w of 80% ( i . e . the molar concentration of water is 44.44 M) and arm polymer concentration of 10% (w/v), PPEGMA-based CCS polymers at >90% yield could be achieved within 1 h. By the same V w and reaction time, PDMAEMA- and PDMA-based CCS polymers could also be prepared with high yield (>75%). The mechanism underlying the formation of the CCS polymers was ascribed to enhanced driving force of polymerization-induced self-assembly at an optimal V w . These CCS polymers were degradable in thiol-containing dithiothreitol, suggesting their potential application for drug release in a reductive intracellular environment.
研究领域:
材料科学
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生物医学工程
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DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2020
·
IF 2.369
Yajun Li,Xiaofang Li,Kui Wu
In this work, the solubility of N,N-dibenzylhydroxylamine (DBHA) in 17 pure solvents, including methanol, ethanol, n-propanol, n-butanol, acetone, ethyl acetate, dichloromethane, acetonitrile, isopropanol, n-octanol, cyclohexanone, 1,2-dichlorobenzene, toluene, isobutanol, n-pentanol, 1,2,4-trichlorobenzene, and tetrahydrofuran, was determined by a static gravimetric method with the temperature ranging from 273.15 to 323.35 K under atmospheric pressure. The solubility of DBHA was positively related to temperature in all selected solvents. Besides, the experimental solubility data were correlated with four thermodynamic models, i.e., the modified Apelblat equation, λh equation, nonrandom two-liquid (NRTL) equation, and the Wilson equation. The results indicated that all of the models could give satisfactory results and the NRTL equation provided the best fitting result. Furthermore, the dissolution thermodynamic parameters in the used solvents, including the Gibbs energy (ΔdisG), molar enthalpy (ΔdisH), and molar entropy (ΔdisS), were calculated according to the Wilson model, and it turned out that the dissolution process of DBHA was endothermic.
研究领域:
物理化学
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热力学
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DOI
高影响因子
FLUID PHASE EQUILIBRIA
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2017
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IF 2.473
Zhiyuan Ma,Anli Xu,Yongqin Du,Jian Wang,Hongkun Zhao,Guowang Diao,Xuedong Zhu,Xuhong Guo
Density, viscosity, refractive index and conductivity of switchable hydrophilicity solvent (SHS) systems ( N,N -dimethylbenzylamine (BDMA), water, and carbon dioxide) were measured as a function of molality of BDMAH-bicarbonate salt for the SHS system at temperatures from (283.15–308.15) K. Three empirical equations were successfully applied to correlate the density, viscosity, refractive index, and electrical conductivity of the SHS systems with temperature and BDMAH-bicarbonate salt concentration. From these experimental results, apparent molar volume , limiting partial molar volume , the relative viscosity and viscosity B -coefficients were calculated. The limiting apparent molar volumes ( V ϕ 0 ) and experimental slopes ( A v ) derived from the Redlich-Mayer type equation have been interpreted in terms of solute-solute and solute-solvent interactions. In terms of Jones-Dole equation, the viscosity B -coefficients with large positive value and dB/dT < 0 were obtained and these facts implied that the BDMAH-bicarbonate salt is water-structure-making.
研究领域:
化学
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物理化学
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DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2024
·
IF 5.7
Chengqiang Li,Zhuoning Cao,Hong Jiang,Francesco Secundo,Xiangzhao Mao
β-N-Acetylhexosaminidases have attracted much attention in the enzymatic synthesis of lacto-N-triose II (LNT2) as a backbone precursor of human milk oligosaccharides (HMOs). In this study, a novel glycoside hydrolase (GH) 20 family β-N-acetylhexosaminidase, FlaNag2353, from Flavobacterium algicola was biochemically characterized and applied to synthesize LNT2. FlaNag2353 displayed optimal activity to p-nitrophenyl N-acetyl-β-d-glucosaminide (pNP-GlcNAc) at 40 °C and pH 8.0. In addition to its excellent hydrolysis activity toward pNP-GlcNAc and chitooligosaccharides, FlaNag2353 showed trans-glycosylation activity. Under conditions of pH 9.0 and 55 °C for 2 h and utilizing 200 mM lactose and 10 mM pNP-GlcNAc, FlaNag2353 synthesized LNT2 with a conversion ratio of 4.15% calculated from pNP-GlcNAc. Moreover, when applied to LNT2 synthesis with 10 mM pNP-GlcNAc and 9.7% (w/v) industrial waste whey powder, FlaNag2353 achieved a conversion ratio of 2.39%. This study has significant implications for broadening the applications of GH20 β-N-acetylhexosaminidases and promoting the high-value utilization of whey powder.
研究领域:
生物化学
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酶学
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食品科学
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生物技术
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）