SCIENCE OF THE TOTAL ENVIRONMENT
·
2021
·
IF 7.963
Lin Shi,Di Zhang,Jinfeng Zhao,Jianliang Xue,Mengnan Yin,Aiping Liang,Bo Pan
The slower adsorption of lower molecular weight organic molecules remains poorly understood. This study investigated the adsorption kinetics of gallic acid (GA) and tannic acid (TA) on kaolinite (Kao), montmorillonite (Mon) and hematite (Hem), with an emphasis on the role of the bound water on the minerals. The lower adsorption of TA and GA on Kao than on Mon attributed to the lower specific surface area of Kao. Because of the electrostatic attraction, the adsorption of TA and GA on Hem was higher than that on Mon, even the specific surface area of the former was much lower than that of the later. The adsorption rates of TA on the three minerals were generally two orders of magnitude higher than those of GA. The adsorption kinetics of GA was strongly diffusion dependent; however, the diffusion process had limited influence on TA adsorption kinetics. The decreased c values of the intraparticle diffusion model of GA with increasing ionic strength provided additional direct evidence for the diffusion-dependent adsorption and the reduced hindrance by bound water via hydration layer compression. However, hydration layer compression had no effect on TA adsorption kinetics. The reduced 1 H NMR relaxation rate of bound water indicated that the bound water quantity on minerals decreased with increasing ionic strength, which proved the occurrence of hydration layer compression. This study highlighted the importance of bound water and the relative sizes of organic molecules in the adsorption kinetics of organic compounds on minerals, which should be carefully considered for their environmental fate studies.
研究领域:
环境科学
·
土壤化学
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DOI
PubMed
高影响因子
MAGNETIC RESONANCE IN CHEMISTRY
·
2017
·Vol. 56
·期 2
·73-79
·
IF 1.601
Xiaochen Tang,Yingjie Xu,Xiao Zhu,Yueqing Lu
In this work, changes in microstructure of two protic ionic liquids (PILs), namely n -butylammonium acetate (N4Ac) and n -butylammonium nitrate (N4NO 3 ), are proved by in situ variable-temperature 1 H NMR spectroscopy at the temperature range from 25 to 115 °C, and the influence of the nature of anion is discussed accordingly. The results demonstrate that 1 H NMR chemical shifts of alkyl protons of both N4Ac and N4NO 3 are almost not changed with the increasing of temperature, due to the absence of hydrogen bond interaction between alkyl protons with anions. Whereas those of + N―H of cation decrease linearly with the temperature increasing, indicating that the hydrogen bond interaction between + N―H and anion weakens gradually. In addition, the strength of hydrogen bond interaction between + N―H and NO 3 − is stronger than that between + N―H and Ac − , suggesting that anions have a significant influence on microstructure due to the acidity of a Brønsted acid. Consequently, the proton transfer from cation to anion is much easier in N4Ac compared to N4NO 3 . Further analyses of 1 H NMR chemical shifts of + N―H in N4Ac at the temperature range from 100 to 115 °C suggest that the splitting of + N―H peak may be attributed to obvious evidence of the existence of the proton transfer from + N―H to Ac − , which leads to dissociate the contact ion-pair in N4Ac to form the neutral ion-pair ‘molecule’. The results will help us to extensively understand the behavior of proton transfer and offer us some valuable information for the design of PILs. Copyright © 2017 John Wiley & Sons, Ltd.
研究领域:
化学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
Polymers
·
2024
·Vol. 16
·期 23
·3254
·
IF 4.7
Jiaqi Wang,Zhaoyutian Chu,Sijia Zheng
Considering the demand for the construction of a sustainable future, it is essential to endow the conventional thermoset silicone adhesive with reuse capability and recyclability. Although various research attempts have been made by incorporating reversible linkages, developing sustainable silicone adhesives by natural linkers is still challenging, as the interface between the natural linker and the silicone is historically difficult. We exploited the possibility of utilizingα-lipoic acid, a natural linker, to construct a sustainable silicone adhesive. Via the simultaneous ring-opening reaction between the COOH and epoxide-functionalized silicone and the polymerization of theα-lipoic acid, the resulting network exhibited dynamic properties. The shear strength of the LASA90 presented strong adhesion (up to 88 kPa) on various substrates including steel, aluminum, PET, and PTFE. Meanwhile, reversible adhesion was shown multiple times under mild heating conditions (80 °C). The rheology, TG-DTA, DSC, and1H NMR showed that the degradation of the LASA occurred at 150 °C via the retro-ROP of the five-membered disulfide ring, indicating their recyclability after usage. Conclusively, we envision that a silicone adhesive based onα-lipoic acid as a natural linker is more sustainable than conventional silicone thermosets because of its desired properties, strong adhesion, reversibility, and on-demand heat degradation.
研究领域:
材料科学
·
化学工程
·
可持续发展
·
粘合技术
·
聚合物化学
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产品关联
DOI
PubMed
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2022
·Vol. 24
·期 34
·20073-20081
·
IF 3.945
Ruifen Shi,Fengyi Zhou,Yu Chen,Zhenghui Liu,Shuzi Liu,Tiancheng Mu
Deep eutectic solvents (DESs) are well-known as novel solvents due to their unique properties, which are indispensable for the development of green chemistry in the future. CoCl2·6H2O and NiCl2·6H2O-based DESs, which could be called magnetic DESs (MDESs) for short in view of their responsive behavior to an external magnetic field, have been widely used in many industrial applications, such as biomass treatment, electrolytes, and material preparation. For better application and full-scale development of these MDESs in various fields, eleven MDESs were prepared in this work by using CoCl2·6H2O and NiCl2·6H2O as hydrogen bond acceptors (HBAs) with alcohols, carboxylic acids and amides as hydrogen bond donors (HBDs), respectively. The intermolecular interactions between the components of MDESs were characterized via FTIR, 1H NMR and DSC analysis. In addition, physicochemical properties including density, viscosity, conductivity, ionicity, pH values, surface tension, thermostability and solvatochromic parameters were investigated. All MDESs exhibit acid characteristics and have good conductivity comparable with ionic liquids (ILs) and other DESs used for electrolytes. The results show that stronger H-bonding networks in Ni-based MDESs make them have higher density, viscosity, polarity and surface tension values than Co-based MDESs. Moreover, all prepared MDESs possess a good conductivity behavior which could be comparable to that of common organic solvents and ILs. According to this work, we could better comprehend the behavior of Co/Ni-based MDESs and choose the appropriate one for particular applications.
研究领域:
化学
·
材料科学
·
绿色化学
·
工业应用
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DOI
高影响因子
JOURNAL OF FOOD PROCESS ENGINEERING
·
2026
·Vol. 49
·期 5
·e70517
·
IF 3.5
Fengping Pang,Wanbing Cheng,Mingyang Liao,Chengtao Nong,Lisha Ye,Ligao Deng,Jianbin Li
To explore the changes in flavor compounds during the hydrolysis of sulfited sugarcane syrup (SS) by sucrase. This study characterized non-volatile organic compounds (NVOCs) via nuclear magnetic resonance (NMR) spectroscopy. Volatile organic compounds (VOCs) were characterized using gas chromatography–mass spectrometry (GC–MS) and gas chromatography–ion mobility spectrometry (GC–IMS). About 14 NVOCs were identified, with 7 NVOCs, including sucrose, fructose, α-glucose, and β-glucose, showing significant dynamic changes. About 80 VOCs were identified by GC–MS. Pyrazines were the predominant compound in the SS, whereas pyrazines and acids became the major components in the hydrolyzed SS. Enzymatic hydrolysis significantly increased the overall VOCs content, particularly acids and aldehydes, while reducing unpleasant S-containing compounds. Orthogonal partial least squares-discriminant analysis (OPLS-DA) revealed that 30 differential VOCs (Variable Importance in Projection, VIP > 1) served as markers for distinguishing among the five syrup samples. Furthermore, three key differential aroma compounds (2,5-dimethylpyrazine, dimethyl sulfide, and β-damascenone) were identified by VIP and Odor Activity Value (OAV). Additionally, we detected 56 VOCs by GC–IMS. The fingerprint profiles and OPLS-DA confirmed significant differences in VOCs during enzymatic hydrolysis. Overall, these findings offer new insights into the flavor chemistry of SS during enzymatic hydrolysis and a theoretical basis for optimizing flavored syrup processing.
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DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2012
·
IF 1.634
Fu Liu,Zhongbo Wei,Liansheng Wang,Zunyao Wang
4,4′-Dihydroxydiphenyl ether and 4,4′-oxybis(1-methoxybenzene) are synthesized. Experimental and theoretical studies on molecular structure, infrared spectra (IR), Raman spectra and nuclear magnetic resonance ( 1 H NMR) chemical shifts of the two synthesized compounds have been worked out. All the theoretical results, which are obtained with B3LYP/6-311G(d,p) method by using the Gaussian 09 program, have been applied to simulate molecular structure, infrared, Raman and NMR spectra of the compounds. The compared results reveal that the calculated geometric parameters match well with experimental values; the scaled theoretical vibrational frequencies are in good accordance with observed spectra; and computational chemical shifts are consistent with the experimental values in most part, except for some minor deviations. These great coincidences prove that the computational method B3LYP/6-311G(d,p) can be used to predict the properties of other similar materials where it is difficult to arrive at experimental results.
研究领域:
化学
·
理论计算化学
·
光谱学
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DOI
高影响因子
Analytical Methods
·
2019
·Vol. 11
·期 48
·6176-6183
·
IF 2.378
Fei-Fei Li,Hui-Xiang Liu,Yan-Li Zhang,Shu-Qi Wang
Absorbable vascular sealing medical glue, which belongs to Class III medical devices, is a special new material for preventing the leakage of cerebrospinal fluid. Medical four-arm poly(ethylene glycol)-N-hydroxysuccinimide-glutarate (4-arm-PEG-SG) with a molecular weight of 20 000 is the main component of the absorbable medical glue. According to its quality standard, the quality control of residues 1,3-dicyclohexylurea (DCU), glutaric acid (GA) and triethylamine (TEA) is required. A rapid analytical method of quantitative 1H nuclear magnetic resonance (1H NMR) for the determination of residues DCU, GA and TEA in medical 4-arm-PEG-SG was established in the present study. The peaks at δ 1.56 (4H, m), δ 2.71 (4H, t, J = 6.7 Hz), and δ 2.42 (6H, q, J = 7.2 Hz) were selected for quantifying DCU, GA and TEA, respectively, with deuterated pyridine as the solvent and tetramethylsilane as the internal standard. The 1H NMR assay was validated by several experimental parameters including specificity, linearity, accuracy, precision, robustness, limit of detection (LOD), limit of quantification (LOQ) and stability. The average recoveries obtained were in the range of 99.48–102.02% for all three residues. Compared with the HPLC and GC approaches, the proposed 1H NMR method proved to be a powerful tool for quantification due to its unique advantages of simplicity, rapidity and high robustness, especially not requiring standard compounds for calibration curve preparation.
研究领域:
医学材料学
·
分析化学
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产品关联
DOI
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2023
·
IF 8.1
Wenjiang Dong,Qidi Hong,Jinhuan Cheng,Hongyan He,Yanan Li,Rongsuo Hu,Yuzhou Long
Green coffee oil (GCO) extracted from green coffee beans, is known for its antioxidant and anticancer properties, and has been increasingly utilised in cosmetic and other consumer products. However, lipid oxidation of GCO fatty acid components during storage may be harmful to human health, and there remains a need to understand the evolution of GCO chemical component oxidation. In this study, proton nuclear magnetic resonance ( 1 H and 13 C NMR) spectroscopy was used to investigate the oxidation status of solvent-extracted and cold-pressed GCO under accelerated storage conditions. Results show that the signal intensity of oxidation products gradually increased with increasing oxidation time, while unsaturated fatty acid signals gradually weakened. Five different types of GCO extracts were clustered according to their properties, except for minor overlapping in the two-dimensional plane of the principal component analysis. Partial least squares-least analysis results demonstrate that oxidation products ( δ = 7.8–10.3 ppm), unsaturated fatty acids ( δ = 5.28–5.42 ppm), and linoleic acid ( δ = 2.70–2.85 ppm) in 1 H NMR can be used as characteristic indicators of GCO oxidation levels. Furthermore, the kinetics curves of unsaturated fatty acids, linoleic, and linolenic acyl groups all fit an exponential equation with high coefficients of GCO for 36 days under accelerated storage conditions. Our results show that the current NMR system is a fast, easy-operated and convenient tool for the oxidation process monitoring and quality control of GCO.
研究领域:
食品科学
·
分析化学
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产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2019
·Vol. 37
·期 9
·919-929
·
IF 2.804
Yang Shi-Xuan,Fan Zi-Yu,Zhang Feng-Yu,Li Si-Hao,Wu Yi-Xian
The random copolymers of isobutylene (IB) with polar comonomers of 4-acetoxystyrene (ACS) or 4- tert -butoxystyrene (TBO), P(IB- co -ACS) and P(IB- co -TBO), could be successfully synthesized via cationic copolymerization with FeCl 3 -based initiating system. The kinetics of the cationic copolymerization process was in situ investigated by inserting a diamond probe into the reaction system by ATR-FTIR spectroscopy. The chemical structure and incorporation content of polar comonomers in the copolymers were characterized by GPC with RI/UV dual detectors and 1 H-NMR spectroscopy. The corresponding functionalized random copolymers of IB with vinyl phenol P(IB- co -POH) carrying phenolic hydroxyl side groups could be further prepared via the complete hydrolysis of acetoxyl side groups in P(IB- co -ACS) or tert -butoxyl side groups in P(IB- co -TBO) copolymers. The functionalized P(IB- co -POH) copolymers became hydrophilic with water contact angle (WCA) of ca . 80° for the self-assembly in hot water, compared to the hydrophobic polyisobutylene with WCA of ca . 110°. The functionalized P(IB- co -POH) copolymers also displayed an excellent self-healing property due to the interaction of intermolecular hydrogen bonding and formation of three dimentional supramolecular networks from phenolic hydroxyl side groups. Furthermore, P(IB- co -POH) copolymers also provided a good matrix for the homogeneous dispersion for silica nanoparticles due to the formation of hydrogen bonding between copolymer chains and silica nanoparticles.
研究领域:
高分子化学
·
材料科学
·
纳米技术
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产品关联
DOI
高影响因子
Journal of Analytical Methods in Chemistry
·
2022
·
IF 2.594
Ziyan Wang,Zuoyuan Wang,Miaomiao Jiang,Jing Yang,Qingfen Meng,Jianli Guan,Maoling Xu,Xin Chai
By employing nuclear magnetic resonance (NMR), we implemented a chemical research on Shuanghuanglian injection (SHLI) and identified 17 components, including eight primary metabolites and nine secondary metabolites. Guided by the approach of network pharmacology, the potential activities were briefly predicted for seven primary metabolites except for formic acid, such as anti-inflammation, antioxidation, and cardiovascular protection. The focused primary metabolites were quantified by a proton nuclear magnetic resonance (1H-NMR) method, which was verified with good linearity and satisfactory precision, repeatability, stability, and accuracy (except for myo-inositol with mean recovery at 135.78%). Based on the successfully established method, seven primary metabolites were effectively quantified with a slight fluctuation in 20 batches of SHLIs. The average total content of these compounds was 6.85 mg/mL, accounting for 24.84% in total solid of SHLI. This research provides an alternative method for analysis of primary metabolites and contributes to the quality control of SHLI.
研究领域:
药理学
·
分析化学
·
中药学
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产品关联
DOI
PubMed
高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2019
·Vol. 26
·期 6
·5804-5813
·
IF 2.914
Meng Zhiyuan,Zhu Wentao,Wang Dezhen,Li Ruisheng,Jia Ming,Yan Sen,Yan Jin,Zhou Zhiqiang
The widespread application of bisphenols (BPs) in the industry has made them ubiquitous in the environment, causing potential environmental risks. Its unknown impacts on human being have received more and more attention. In this study, we have assessed the metabolic effects of perinatal exposure to bisphenol A (BPA) and its substitutes (bisphenol S (BPS), bisphenol F (BPF), and bisphenol AF (BPAF)) in female mice adolescent offspring and female mice adulthood offspring. 1 H NMR-based serum metabolomics showed that metabolic profiles were disturbed with BPA and its three substitutes exposure in female mice adolescent offspring and female mice adulthood offspring. In addition, age-related metabolic effects were found based on changes in serum endogenous metabolites and metabolic pathways. Specifically, metabolic pathway analysis showed that major disturbed metabolic pathways in female mice adulthood offspring compare with female mice adolescent offspring also changed significantly. With the increase of age of the female mice offspring, changes in the metabolic pathways became more obvious in the BPA treatment group. Conversely, partially disturbed metabolic pathways were restored in the BPS, BPF, and BPAF treatment groups. In conclusion, perinatal exposure to BPA and its three substitutes significantly interferes with metabolic profiles and metabolic pathways, and this metabolic effects were age-related. These results offer more detailed information about the age-related metabolic effects of perinatal exposure to BPA, BPS, BPF, and BPAF in female mice offspring and provide data for systematic evaluation of the health risk assessment of BPA and its substitutes.
研究领域:
环境毒理学
·
代谢组学
·
发育生物学
·
生殖毒理学
·
分子毒理学
·
环境健康
·
生命早期暴露
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2016
·Vol. 40
·期 3
·2530-2540
·
IF 3.277
Hongqin Yang,Yanmei Huang,Di Wu,Jin Yan,Jiawei He,Hui Li
Sofosbuvir (SOF), an oral nucleotide inhibitor of the nonstructural protein 5B RNA of the hepatitis C virus (HCV), was approved for treating chronic HCV infection by the Food and Drug Administration in 2013. Understanding drug–protein interactions is a crucial factor in determining the pharmacokinetics and pharmacodynamics of a drug. In this study, the interaction between SOF and human serum albumin (HSA) was investigated using 1H nuclear magnetic resonance (NMR) spectroscopy, the molecular docking method, fluorescence studies, Fourier transform infrared (FT-IR) spectroscopy, and circular dichroism (CD) spectroscopy. The analysis of saturation transfer difference (STD) and WaterLOGSY data indicated that SOF was bound to HSA, and the STD signals showed that the methyl and aromatic protons of the hydrophobic components of SOF have the most intimate contact with protein. The negative free energies (−7.17 kcal mol−1 and −6.18 kcal mol−1) obtained from molecular docking and fluorescence studies clearly suggested the spontaneity of the interaction of the SOF–HSA complex. STD, WaterLOGSY and fluorescence displacement experiments demonstrated that SOF was preferentially bound to site I of HSA, and this finding was supported by the docking results. In addition, synchronous and three-dimensional (3D) fluorescence, FT-IR, and CD spectrocopy provided complementary information on the micro-environmental and conformational changes of HSA with the addition of SOF. The combination of 1H NMR and conventional methods provided useful information to further elucidate the binding mechanisms of antiviral drugs with HSA.
研究领域:
病毒学
·
药理学
·
生物化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）