JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2025
·
IF 2.1
Rui-Zhi Cui,Guo-Liang Nie,Hong-Bao Ren,Qiu-Ye Yang,Wu Li
The underground brine in the Sichuan basin is not only widely distributed but also of excellent quality, which has broad prospects for comprehensive development and utilization. Due to the complex geological structure and relatively high air humidity in the Sichuan basin, salt field technology cannot be used for the separation and enrichment of brine resources. Therefore, forced evaporation by external energy can only be used to achieve the purpose of the preliminary separation of salts. In order to realize effective development and utilization of this underground brine resource, it is necessary to carry out multitemperature phase equilibrium research from ambient to high temperature for this brine system. Here, we take lithium-, potassium-, and bromine-rich underground brine in the Sichuan basin as research object and use the isothermal dissolution equilibrium method to research the stable phase equilibria of two ternary systems (LiBr–NaBr–H2O and LiBr–KBr–H2O) under temperature conditions of 373.15, 398.15, and 423.15 K. Based on the experimental results, the corresponding phase diagrams were drawn, and the phase diagrams under different temperature conditions were compared to reveal the phase equilibrium relationship and crystallization–dissolution rules of each component in the above two systems under multitemperature conditions.
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高影响因子
Algal Research-Biomass Biofuels and Bioproducts
·
2026
·
IF 5
Ziqi Yu,Shiying Tang,Ming Du,Yong Zhao,Xiangrong Li,Ruihan Xu,Qixiang Zhou,Hui Zhou,Dandan Ren,Xiaoting Yu,Long Wu
TEMPO/NaClO/NaBr is applied to controlled degradation of fucoidan. • TEMPO/NaClO/NaBr enables efficient LMWF production from fucoidan in 0.5 h. • Galactose changes are consistent with possible C6 oxidation under TEMPO mediation • The TEMPO-free system caused 18.97% fucose loss and 6.13% sulfate loss. Low-molecular-weight fucoidan (LMWF) is highly desirable for food and pharmaceutical applications, yet conventional degradation methods often compromise its bioactive sulfate content. In this study, we employed a TEMPO/NaClO/NaBr system to degrade fucoidan under mild alkaline conditions and systematically investigated the degradation kinetics, structural changes, and anticoagulant activity of the resulting LMWF products. The degradation process was monitored by NaOH consumption and molecular weight distribution analysis. The optimal reaction time was determined to be 0.5 h, during which the molecular weight decreased from 337.4 kDa to 24.3 kDa, yielding LMWF with a relatively narrow molecular weight distribution (PDI = 1.08). Structural characterization by monosaccharide composition analysis, FT-IR, and 1 H NMR suggested that TEMPO-mediated oxidation favored oxidation at C6 primary hydroxyl groups, as indicated by changes in galactose and galacturonic acid contents, while no significant loss of total sulfate content was observed. In contrast, the non-selective NaClO/NaBr system caused substantial losses of fucose (18.97%) and total sulfate content (6.13%). Notably, the TEMPO-derived LMWF retained potent anticoagulant activity in the APTT assay while exerting a minimal effect on the PT pathway, suggesting a potentially lower bleeding risk. This study provides a promising strategy for the controlled preparation of LMWF with minimal loss of total sulfate content and a potentially favorable safety profile. Download: Download high-res image (175KB) Download: Download full-size image
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高影响因子
Journal of CO2 Utilization
·
2016
·
IF 4.764
Jia-Ning Xie,Zhen-Feng Diao,Chang Qiao,Ran Ma,Liang-Nian He
Efficient synthesis of cyclic carbonates from olefins using K 2 S 2 O 8 as oxidant and NaBr as “bromination” reagent has been developed through a reaction sequence involving hydroxybromination of olefins and subsequent carboxylation of the bromohydrin in situ generated with CO 2 . This process provides a novel and convenient access to cyclic carbonates in a one-pot stepwise fashion. Representative olefins with different functional groups could react smoothly under relatively mild (3 MPa, 60 °C) and transition metal-free conditions to afford various cyclic carbonates.
研究领域:
有机化学
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绿色化学
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二氧化碳利用
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合成方法学
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高影响因子
NEW JOURNAL OF CHEMISTRY
·
2018
·Vol. 42
·期 8
·6274-6282
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IF 3.201
Shuang Chen,Hao Wu,Jing-han Hua,Jing-wen Yang,Hong-bin Zhang,Xue-qin Hu
Dextran is a polysaccharide with a high medicinal value. Thus, the chemical modifications of dextran, and the structural and physicochemical properties of its derivatives should be given focus. Dextran (Mw 5000 Da to 7500 Da) can complex with iron. In this study, dextran (Mw 5400 Da) was modified at different pH levels (8–14) by using NaOH and NaClO/NaBr. The carboxyl groups of the modified dextran were determined using infrared spectroscopy, and the carboxyl contents were compared. The results of high-performance liquid chromatography indicated that dextran was degraded during the modification. The crystallization and the structure of the carboxyl-modified dextran were investigated using X-ray diffraction, nuclear magnetic resonance, and quadrupole time-of-flight mass spectrometry. The physicochemical properties, i.e., solubility, and granule morphology, of the carboxyl-modified dextran were carefully characterized and compared. This work provides a theoretical foundation for the accurate selection of carboxyl-modified dextran and the development of a novel strategy for the preparation of metal complexes.
研究领域:
生物化学
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材料科学
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高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Xiu-Zhi Wei,Fentahun Wondu Dagnaw,Jianguo Liu,Longlong Ma
Carboxylic acid is one of the most crucial and widely used organic chemicals in daily human life activities. Hence preparation of this important chemical was performed under the application of the highly selective photo-catalysts through oxidation of alcohols to carboxylic acids. Herein, we have designed and disclosed a binary NH 2 -MIL-125(Ti)/ NaBr) catalyst system to realize the effective transformation of alcohols into carboxylic acids under visible light irradiation . Hence, derivatives of benzyl alcohol containing either electron withdrawing and donating groups as well as aliphatic primary alcohols were effectively converted into the corresponding carboxylic acids. Based on our findings, NH 2 -MIL-125(Ti) based photocatalytic system has shown efficient and highly selective activities for oxidation of alcohol especially the in-situ conversion of co-catalyst NaBr into the corresponding free radical can enhance the alcohol oxidation performance of the catalytic system.
研究领域:
化学
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催化
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材料科学
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光化学
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DOI
PubMed
高影响因子
ACS Omega
·
2022
·
IF 4.132
Guo-liang Nie,Rui-zhi Cui,Zhong Liu,Wu Li
In view of the composition characteristics of lithium, calcium, and bromine rich in Nanyishan oilfield water of the Qaidam Basin, Qinghai Province, the phase equilibrium relationships of quaternary system LiBr–NaBr–KBr–H2O and its ternary subsystems LiBr–NaBr–H2O and LiBr–KBr–H2O at 348.15 K were studied by the isothermal solution equilibrium method, and the equilibrium solid-phase crystallization regions and composition of each invariant point in each system were determined. The results show that there is no complex salt or solid solution in ternary systems LiBr–NaBr–H2O and LiBr–KBr–H2O at 348.15 K, and the phase diagram contains only one invariant point, two isothermal univariate curves, and two equilibrium solid-phase crystallization regions. The quaternary system LiBr–NaBr–KBr–H2O also has no formation of complex salt or solid solution, and the phase diagram contains only one invariant point, three isothermal univariate curves, and three equilibrium solid-phase crystallization regions. Meanwhile, the phase equilibrium relationships and change laws of each component of the above-mentioned systems at different temperatures were compared and discussed.
研究领域:
化学工程
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物理化学
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PubMed
高影响因子
Frontiers in Chemistry
·
2023
·
IF 5.5
Cui Ruizhi,Peng Changwei,Nie Guoliang,Sang Shihua,Ren Hongbao,Li Wu
In view of the composition characteristics of lithium, calcium and bromine rich in Nanyishan oil and gas field brine of western Qaidam Basin, Qinghai Province, as well as based on the results reported in relevant literature, the phase equilibrium relationship of ternary system LiBr-CaBr2-H2O at 298.15 K was studied by isothermal dissolution equilibrium method. The equilibrium solid phase crystallization regions, as well as the compositions of invariant point, in phase diagram of this ternary system were clarified. On basis of the above ternary system research, the stable phase equilibria of quaternary systems (LiBr-NaBr-CaBr2-H2O, LiBr-KBr-CaBr2-H2O and LiBr-MgBr2-CaBr2-H2O), as well as quinary systems (LiBr-NaBr-KBr-CaBr2-H2O, LiBr-NaBr-MgBr2-CaBr2-H2O and LiBr-KBr-MgBr2-CaBr2-H2O) were further carried out at 298.15 K. According to the above experimental results, the corresponding phase diagrams at 298.15 K were drawn, which revealed the phase relationship of each component in solution and the law of crystallization and dissolution, and meanwhile summarized changing trends. The research results of this paper lay a foundation for further research on the multitemperature phase equilibria and thermodynamic properties of lithium and bromine containing high-component brine system in later stage, and also provide basic thermodynamic data for guiding the comprehensive development and utilization of this oil and gas field brine resource.
研究领域:
化学
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热力学
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PubMed
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2022
·
IF 3.119
Xing-Xing Zeng,Shi-Hua Sang,Xiao-Yun Qi,Xiao-Feng Guo,Rui-Zhi Cui
Aiming at the composition of underground brines in the Sichuan Basin of China, stable phase equilibria in quaternary systems LiBr–NaBr–SrBr2–H2O and LiBr–KBr–SrBr2–H2O at 288.15 K are studied using the isothermal dissolution equilibrium method. The solubilities of salts in the quaternary systems listed above are measured, and the corresponding equilibrium solid phases are identified using X-ray powder diffraction. As a result, the corresponding phase diagrams of the two quaternary systems are plotted, respectively. In the two stable phase diagrams, there is no solid solution or complex salt at 288.15 K. For the quaternary system LiBr–NaBr–SrBr2–H2O, there are two invariant points, five univariate curves, and four solid crystallization regions, which are LiBr·2H2O, NaBr, NaBr·2H2O, and SrBr2·6H2O, respectively, of which LiBr·2H2O has the smallest crystallization field, indicating that its solubility is the largest and it is the hardest to be precipitated from the saturated solution. There are one invariant point, three univariate curves, and three solid crystallization fields, corresponding to LiBr·2H2O, KBr, and SrBr2·6H2O in the quaternary system LiBr–KBr–SrBr2–H2O, respectively. The experimental results show that the solubilities of salts KBr, NaBr, and SrBr2 in the saturated solution decrease with the increasing concentration of LiBr, which indicates that LiBr has a strong salting out effect on KBr, NaBr, and SrBr2 in the solution.
研究领域:
化学
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材料科学
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高影响因子
CELLULOSE
·
2021
·Vol. 28
·期 18
·11315-11328
·
IF 5.044
Wang Huimin,Wang Xiaoying,Sun Tingting,Li Peixin,Chu Xiaomeng,Xing Xuteng,Liu Shaojie,Tang Erjun
As a highly efficient nitroxide radical catalyst for selective catalytic oxidation of cellulose, N-hydroxyphthalimide (NHPI) has attracted much attention because of its low price and light cellulose degradation. However, NHPI is insoluble in water and is difficult to recycle because of its small molar mass. To address the above issues, the water-soluble polyethylene glycol (PEG)-immobilized NHPI catalyst (PEG-NHPI) was designed and prepared in this work. Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance spectroscopy (NMR), size exclusion chromatography (SEC) and UV–Vis light spectrophotometry were used to characterize PEG-NHPI. The results showed that PEG-NHPI catalysts with good water solubility and adjustable NHPI loading amounts were successfully synthesized. Using NaBr as promoter and NaClO as oxidant, PEG-NHPI mediated oxidation of cellulose was carried out and good catalytic performance was found. The catalytic performance of PEG-NHPI mediated oxidation of cellulose in water was higher than that in acetonitrile–water. The carboxyl content of PEG-NHPI oxidized cellulose could reach the level of free NHPI oxidized cellulose, and was equivalent to 68% of 2, 2, 6, 6-tetramethylpiperidine-N-oxyl (TEMPO) oxidized cellulose, while the degradation degree of cellulose was greatly reduced by more than 40%. The catalytic performance did not decrease significantly after six oxidation cycles. The structure of recycled PEG-NHPI was not changed. These results indicated that immobilizing NHPI onto PEG can achieve the unification of high catalytic performance and good recyclability.
研究领域:
化学工程
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材料科学
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DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2022
·
IF 3.119
Guo-Liang Nie,Rui-Zhi Cui,Wu Li
According to the composition characteristics of lithium, potassium, bromine, and other resources rich in the salt lake brine of the Qinghai–Tibet Plateau, the phase equilibria of the quaternary system LiBr-NaBr-KBr-H2O and its ternary subsystem LiBr-KBr-H2O at 323.15 K are studied by an isothermal dissolution equilibrium method. The solubility of each system in equilibrium solution at the corresponding temperature is measured, and the corresponding phase diagrams are drawn according to the phase equilibrium experimental data. The results show that there is no complex salt or solid solution in the ternary system LiBr-KBr-H2O at 323.15 K. The phase diagram contains one invariant point (E1), two univariate curves (AE1 and BE1), and two equilibrium solid crystallization regions (corresponding to LiBr·H2O and KBr), belonging to the simple cosaturated type. The quaternary system LiBr-NaBr-KBr-H2O also has no formation of complex salt and solid solution. The phase diagram contains two invariant points (F1 and F2), five univariate curves (E1F1, E3F1, F1F2, E2F2, and E4F2), and four equilibrium solid-phase crystallization regions (corresponding to LiBr·H2O, KBr, NaBr·2H2O, and NaBr). At the same time, to further explain the phase equilibrium relationship of each system at different temperatures and the change rule of each component, comparison and discussion are carried out.
研究领域:
化学工程
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材料科学
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高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2020
·Vol. 36
·期 6
·1234-1240
·
IF 1.063
Cui Ruizhi,Li Wu,Dong Yaping,Li Jun
The stable phase equilibria of quaternary systems LiBr-NaBr-MgBr 2 -H 2 O and LiBr-KBr-MgBr 2 -H 2 O at 298.15 K were studied by both experimental measurement(isothermal solution saturation method) and theoretical prediction(Pitzer model). The solubilities of the saturated solution have been determined experimentally and two stable phase diagrams and relevant water diagrams of the two quaternary systems were obtained. Results show that quaternary system LiBr-NaBr-MgBr 2 -H 2 O is hydrate II type as NaBr and NaBr·2H 2 O coexistence. Its phase diagram consists of only one invariant point, four univariant curves, and five crystallization fields. The quaternary system LiBr-KBr-MgBr 2 -H 2 O is a complex type as the double salt KBr·MgBr 2 ·6H 2 O formed. In addition to this double salt, the three single salts LiBr·2H 2 O, KBr and MgBr 2 ·6H 2 O also crystallize. In this paper, the solubilities of phase equilibria in above quaternary systems were also calculated by the Pitzer’s electrolyte solution model. All the needed parameters can be obtained from the literature or be fitted by experimental data. On the Basis of the experimental and calculated results, the phase diagram of the quaternary system was plotted for comparison. It shows that the calculation results are consistent with the experimental ones.
研究领域:
化学热力学
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无机化学
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高影响因子
MOLECULES
·
2024
·Vol. 29
·期 21
·5166
·
IF 4.2
Peng Wang,Xu Zhang,Xi Le,Junjun Chen,Guangyan Zhang,Junjian An,Nianjie Feng,Junxian Xie
A thorough understanding of the lignin–carbohydrate complex (LCC) structure has a significant meaning in the high-value utilization of lignocellulose. In this work, the complex (DHPKGC) was obtained by an addition reaction between konjac glucomannan (KGM) and quinone methides generated in the synthesis of dehydrogenation polymers (DHPs) to simulate the formation of LCCs. The effect of pH on the prepared DHPKGC was investigated. The structure of the DHPKGC was characterized by Fourier Transform Infrared (FTIR),13C-Nuclear Magnetic Resonance (13C-NMR), and two-dimensional Heteronuclear Single Quantum Coherence Nuclear Magnetic Resonance (2D HSQC NMR) analyses. The results indicated the pH of 4.0 was conducive to the polymerization reaction between DHPs and oxidized KGM by the TEMPO/NaClO/NaBr system. In addition, the resultant DHPKGC was connected by benzyl ester linkages. Overall, this study aims to gain greater insight into the process of LCC formation in plants.
研究领域:
化学
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材料科学
·
生物化学
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PubMed
高影响因子
危险品化学品经营许可证（带存储）