FLUID PHASE EQUILIBRIA
·
2022
·
IF 2.745
Feng Liu,Li Chen,Kangling Yin,Taotao Fan,Zongcheng Yan
In this work, a novel liquid–liquid biphasic system of sugar-based deep eutectic solvents (DESs) was studied. The liquid–liquid biphasic system was formed when sugar-based DESs and n-propanol (NPA) showed incompatibility in an aqueous solution at above critical concentrations and 298.15 K. The DESs were prepared by choline chloride and sugars (sucrose, glucose, fructose, and xylose). The influence of the hydroxyl group and structure of HBD on the phase behavior was evaluated using phase diagrams and tie-lines length (TLL). Results showed that the biphasic region of DESs-based system was expanded by enhancing the hydrophilic of HBD. Each HBD (sucrose, glucose, fructose) and choline chloride can form ternary system with NPA and water. With this phase behavior, the molar ratio of DESs in two phases is the same as the original ratio of the DES formation. A non-random two-liquid (NRTL) model was used to correlate the tie-lines data of the systems, and the binary interaction parameters of the model were then obtained. Shikimic and vanillic acids used as biomolecule probes in two phases was studied to further explore the extraction potential of these DES-based systems. This work showed that the nature of HBDs influences the distribution behavior of shikimic and vanillic acids. And the DES-based systems presented higher extraction efficiencies (from 88.02% to 91.90%) for shikimic acid, which shows good extraction levels.
研究领域:
化学工程
·
生物技术
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DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Yichen Jiang,Dazhi Li,Yifei Zhao,Jianmin Sun
Hydrogen bond donor functionalized poly(ionic liquids) were incorporated into MIL-101 framework for synthesis of composites PIL-R@MIL-101 (R = COOH, OH, NH 2 ). The effect of different hydrogen bond donors on CO 2 -epoxide cycloaddition reaction was discussed through XPS, NH 3 -TPD characterizations. Thereinto, PIL-COOH@MIL-101 showed efficient catalytic performance in the cycloaddition reaction of CO 2 and epichlorohydrin , 92.7% substrate conversion was obtained under 70 °C, 1.0 MPa, cocatalyst- and solvent-free conditions for 2.5 h. The improved activity was benefited from the synergistic effects of Lewis acidic Cr centers, carboxyl group, and nucleophilic Br - , together with the high surface area (1178 m 2 /g), and good CO 2 affinity. In addition, PIL-COOH@MIL-101 also showed facile recovery method by easy centrifugation and good recycling stability. Considering the good CO 2 affinity, excellent catalytic performance in CO 2 cycloaddition reaction, better thermal and recycling stabilities, the facilely prepared functionalized poly(ionic liquid)@MIL-101 composite would exhibit promising application prospect in CO 2 capture and conversion.
研究领域:
材料科学
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化学工程
·
环境科学
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产品关联
DOI
PubMed
高影响因子
EUROPEAN POLYMER JOURNAL
·
2018
·
IF 3.741
Songquan Xu,Hui Zhu,Zhenjiang Li,Fulan Wei,Yu Gao,Jiaxi Xu,Haixin Wang,Jingjing Liu,Tianfo Guo,Kai Guo
H-bond donor (HBD) and base co-catalysis achieved great success in ring-opening polymerization (ROP). Parallel H-bond donor and Brønsted acid (HBD–BA) cocatalysis has been scarcely explored in ROPs. In developing the HBD–BA catalysis in to versatile toolbox for ring-opening polymerizations of wider scope and better control, tunable HBDs including boronate pinacol ester urea (BU), urea (U), and thiourea (TU) were evaluated in cooperation with trifluoroacetic acid (TFA) in HBD–BA catalytic mode. Each of the HBD–TFA co-catalyst promoted ROPs of δ-valerolactone (VL) and ε-caprolactone (CL) successfully. The catalytic performances of the HBD–TFA on the HBD part was in an order of BU > U > TU to their corresponding ROPs of VL and CL. The turnover frequencies of the catalyzed ROPs of VL and CL by BU–TFA was twice as that of TFA. The ROPs afforded homopolymers with predicted molecular weights (PVL, M n,NMR = 2.51–9.92 kg mol −1 ; PCL, M n,NMR = 2.51–11.1 kg mol −1 ) and narrow dispersities (PVL, Đ ≤ 1.16; PCL, Đ ≤ 1.18) by ratios of monomer to initiator from 20 to 100. The obtained polymers were analyzed by 1 H NMR, 13 C NMR, and MALDI-ToF MS, the results indicated the high chain-end fidelity. Chain extension experiments were conducted by a first ROP of VL/CL and second ROP of CL/VL with precise molecular weights (from 2.98 kg mol −1 to 6.15 kg mol −1 ) and narrow dispersities below 1.18. The kinetics plots showed a distinct first order relationship between ln([VL] 0 /[VL]) versus the reaction time, it indicated the controlled nature of the catalytic ROP. NMR titrations supported the proposed mechanism that HBD associated with TFA and promoted the cationic polymerization.
研究领域:
高分子化学
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催化化学
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DOI
高影响因子
GREEN CHEMISTRY
·
2016
·Vol. 18
·期 10
·3089-3097
·
IF 8.506
Yan Wang,Yucui Hou,Weize Wu,Dongdong Liu,Youan Ji,Shuhang Ren
As analogues of ionic liquids, deep eutectic solvents (DESs) have attracted considerable attention in the field of separating aromatics from aromatics/aliphatics mixtures. In this work, the performance of a series of DESs was evaluated for their selective extraction of toluene from toluene/n-heptane mixtures. The results showed that the extraction ability for toluene using DESs was greatly influenced by hydrogen bond acceptors (HBAs) and hydrogen bond donors (HBDs) which formed the DESs. The selectivity of toluene was distinctly enhanced by short side chains, a small central atom of the cation and a large anion of the HBA, together with a suitable position for an alkyl chain and appropriate functional group of the HBD. It was also found that an increase of extraction temperature at the studied range could enhance the selectivity for toluene. This work makes the roles of HBAs and HBDs clear in the extraction of aromatics, providing information for designing more effective DESs for aromatics extraction.
研究领域:
化学工程
·
分离科学
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DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2020
·
IF 3.862
Yuejia Zhu,Yongzhu Hu,Zhenjiang Li,Bo Liu,Yuanyuan Qu,Zhihao Zhang,Tianfo Guo,Yongqiang Li,Luoyu Gao,Kai Guo
Hydrogen bond donor (HBD) and organic base binary cocatalyst established a gold standard in organocatalytic ring-opening polymerizations (ROPs). In depth probe of the mechanisms revealed that proton abstraction of the acidic H on the HBDs by the bases do occur frequently. A truly simple HBD and Lewis base (LB) cocatalysis, however, was elusive. We proposed genuine HBD/LB cocatalyst for ROPs by introducing 3-amino-1,2,4-benzothiadiazine-1,1-dioxide (ABTD) as a bidentate H-bond donor and triethylamine (TEA) as a mild Lewis base. ROPs of lactide (LA) and trimethylene carbonate (TMC) in solutions at room temperature were success. The mild ROPs produced polylactide (PLA) of predictable molecular weights (from 1.6 to 26.7 kg mol −1 ) and extremely narrow dispersities (Đ 1.01 to 1.06). Furthermore, well-defined diblock copolymers PTMC-b-PLA were synthesized. NMR titration experiments verified exclusive H-bond donor activation of the monomer and TEA activation of the hydroxyl chain end without trace of proton abstraction.
研究领域:
化学
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材料科学
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DOI
高影响因子
JOURNAL OF PHARMACEUTICAL SCIENCES
·
2019
·
IF 3.197
Zheng Luo,Chao Liu,Peng Zhang,Peng Quan,Xingzhong Cao,Liang Fang
In the present study, a pyrrolidone adhesive and an amide adhesive were synthesized, and their molecular mechanisms of controlled drug release were described. Using zolmitriptan as model drug, in vitro drug release and skin permeation experiments were performed. Adhesive properties were evaluated using modulated differential scanning calorimetry and rheology study. Free volume of polymer was directly obtained by positron annihilation lifetime spectroscopy. Intermolecular interactions between drugs and adhesives were determined by FTIR spectroscopic analysis and molecular simulation. Release percent (24 h) of zolmitriptan from pyrrolidone adhesive was about 55.8 ± 3.1% (w/w), while from amide adhesive, the release percent (24 h) was about 40.1 ± 1.6% (w/w). The free volume sizes of pyrrolidone adhesive and amide adhesive were about 2309.6 Å 3 and 2854.5 Å 3 , respectively, which were much larger than molecular volume of zolmitriptan (about 285.7 Å 3 ). Thus, the polymer networks might not hinder drug diffusion from the view of free volume. Comparing chemical structures of pyrrolidone group and primary amide group, the main difference was that primary amide group of amide adhesive possessed 2 hydrogen donors. It was proved that hydrogen bonding between zolmitriptan and hydrogen donor of primary amide group played a critical role in controlling drug release.
研究领域:
药剂学
·
材料科学
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DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Fuxin Yang,Qiang Zheng,Houzhang Tan,Xiaopo Wang
Deep eutectic solvent (DES) is considered as one of the green solvents with bright prospect in this century. Its excellent performance is closely related to the hydrogen bonds formed between hydrogen bond acceptor (HBA) and hydrogen bond donor (HBD). Through changing the type of HBD and adjusting its molar fraction, it makes a difference to the intensity of the hydrogen bonds. In this work, tetrabutylammonium chloride (TBAC) was chosen as HBA, decanoic acid (DEC) and octanoic acid (OC) were chosen as HBD. With the molar ratios ranging from 3:1 to 1:3, seven TBAC-DEC-based DES and seven TBAC-OC-based DES were synthesized. Based on the study of the structural characteristics and the thermophysical properties, such as the eutectic point, the thermal stability, the density and the viscosity, the effect of HBD on DES was investigated. The increased HBD destroyed the orderly configuration of DES. Meanwhile, the elongation of the HBD’s alkyl chain enhanced the interaction between the components. Moreover, the mass-connectivity-based model and the hard sphere model were introduced to predict the density and viscosity, respectively. Both of the two models exhibited good predictivity, with the average absolute relative deviation less than 0.2 % and 5 %, respectively.
研究领域:
化学
·
材料科学
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Xin Wang,Li Yang,Yanglin Chen,Chaokun Yang,Jianwen Lan,Jianmin Sun
The silicon-based materials with enriched superficial Si–OH groups are candidates in the field of the cycloaddition of CO2 to epoxide to cyclic carbonate; meanwhile, the triazine ring with a nitrogen-rich structure has shown a high adsorption affinity toward CO2 to polarize CO2. On this basis, a metal-free triazine-incorporated organosilica framework (SiTIOF) containing triazine rings, −NH, and Si–OH was prepared by substitution reaction and then a hydrothermal method. The prepared SiTIOF exhibited an outstanding catalytic activity for the cycloaddition of CO2 to epoxide with the cocatalyst tetrabutylammonium bromide (Bu4NBr) due to the triazine unit and multiple hydrogen bond donors (−NH, −OH). Besides, the SiTIOF catalyst could be reused six times and has good versatility to various epoxides with CO2 cycloaddition. Moreover, the possible reaction mechanism with a hydrogen bond donor (HBD) and halide anion synergistic catalysis was proposed.
研究领域:
材料科学
·
催化化学
·
环境化学
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DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2021
·
IF 3.764
Shijie Xu,Yaqing Bu,Shuwan Jiang,Penghui Yang,Yanfei Wang
In this paper, the nucleation behavior of glutaric acid (GA) in solvents with different hydrogen-bond donating (HBD) capabilities was studied using a metastable zone width (MSZW) experiment and modified Sangwal’s theory. Through designing different cooling rates, saturation temperatures, and solvents with different HBD capabilities, it is demonstrated that the MSZWs increase when increasing the cooling rate or decreasing the saturation temperature or increasing the HBD capability. Interestingly, under the framework of the classical nucleation theory, we find that the critical nuclei size and critical Gibbs free energy do not monotonically change with the increase of driving force in the three solvents, which means that the solid–liquid interface energy changes with the driving force. Finally, we suggest that with increasing HBD capability, desolvation of glutaric acid becomes more and more difficult, thus leading to a wider metastable zone width, which indicates that desolvation may be the rate-determining step in the nucleation process.
研究领域:
化学工程
·
物理化学
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产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2015
·Vol. 17
·期 8
·5959-5965
·
IF 4.493
Mengshuai Liu,Kunqi Gao,Lin Liang,Fangxiao Wang,Lei Shi,Li Sheng,Jianmin Sun
Catalytic coupling of carbon dioxide with epoxides to obtain cyclic carbonates is an important reaction that has been receiving renewed interest. In this contribution, the cycloaddition reaction in the presence of various hydrogen bond donors (HBDs) catalyzed by hydroxyl/carboxyl task-specific ionic liquids (ILs) is studied in detail. It was found that the activity of ILs could be significantly enhanced in the presence of ethylene glycol (EG), and EG/HEBimBr were the most efficient catalysts for the CO2 cycloaddition to propylene oxide. Moreover, the binary catalysts were also efficiently versatile for the CO2 cycloaddition to less active epoxides such as styrene oxide and cyclohexene oxide. Besides, the minimum energy paths for this hydrogen bond-promoted catalytic reaction were calculated using the density functional theory (DFT) method. The DFT results suggested that the ring-closing reaction was the rate-determining step in the HEBimBr-catalyzed cycloaddition reaction but the EG addition could remarkably reduce its energy barrier as the formation of a hydrogen bond between EG and the oxygen atom of epoxides led this process along the standard SN2 mechanism. As a result, the ring-opening reaction became the rate-determining step in the EG/HEBimBr-catalyzed cycloaddition reaction. The work reported herein helped the understanding and design of catalysts for efficient fixation of CO2 to epoxides via hydrogen bond activation.
研究领域:
化学
·
环境科学
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2022
·
IF 9.231
Min Liu,Simin Wang,Wentao Bi,David Da Yong Chen
A deep eutectic system (DESys) is formed when a hydrogen bond acceptor (HBA) is processed with polysaccharide (hydrogen bond donor, HBD) containing plant substance in water to dissolve, extract, and recover the polysaccharide directly, instead of using a traditional deep eutectic solvent (DES). The extraction efficiency is enhanced by the direct formation of the DESys, in a mechanochemical extraction (MCE) system. Key factors affecting the extraction efficiency were systematically studied and optimized. The effects of the DESys on the structure and physicochemical properties of polysaccharides were studied by several analytical techniques. The findings demonstrated that the direct DESys formation extraction efficiency was superior than that of traditional extraction methods while retaining physicochemical properties of polysaccharides. Moreover, the composition of polysaccharides extracted with this method is different from that obtained by conventional methods. The recovery and purification process of polysaccharides is simplified by eliminating the need for an additional HBD.
研究领域:
植物学
·
食品科学
·
化学工程
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Xiangyu Wang,Mingwei Zhao,Xuhao Wang,Peng Liu,Mengyao Fan,Xiaowei Yan,Zhenfeng Ma,Yanfang Zhang,Caili Dai
Petroleum remains the main source of energy consumption over the past decade. The development of rich unconventional oil reservoirs is a huge challenge. Clean fracturing fluids (CFFs) have gained considerable attention for the unconventional reservoir development, owing to their integrated capabilities of fracturing and oil expulsion. Performance of CFFs is a vital factor in enhancing oil recovery. In this work, a ternary deep eutectic solvent (DES) with dual hydrogen donors (HBDs) was developed as a novel and green medium for improving CFF performance. With the hydrogen-bonding interactions, the ternary DES enable a robust micelle network, thereby strengthening the rheological property, temperature resistance and drag reduction performance of CFFs. The salt resistance performance was improved due to the ion–dipole interaction between HBDs and salt cations, decreasing the interactions between salt cations and surfactants. The DES also increase the imbibition efficiency from 30.7 % in 98 h to 43.7 % in 62 h. Besides, the gel breaking performance and reusability of gel-breaking fluid were enhanced in the presence of DES. The ternary DES showed more effective reinforcement for CFF properties as compared with binary DES, due to the synergistic effect of dual HBDs. This work will provide a promising alternative for intensifying CFF performance.
研究领域:
石油工程
·
绿色化学
✓ 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）