JOURNAL OF APPLIED POLYMER SCIENCE
·
2012
·Vol. 127
·期 1
·402-409
·
IF 1.289
Haohua Ye,Zhanxiong Li,Guoqiang Chen,Dan Fan
Bis (1H, 1H, 2H, 2H-perfluoro-octyl)methylenesuccinate (FOM)/ethyl acrylate (EA)/methyl methacrylate (MMA) copolymer (FOME) latexes, FOM/butyl acrylate (BA)/MMA copolymer (FOMB) latexes, and FOM/octyl acrylate (OA)/MMA copolymer (FOMO) latexes were synthesized by continuous emulsion polymerization. Solution polymerization was also carried out to prepare FOMB. The influences of fluorine content and curing conditions on the surface properties of polymer films were discussed. The water and oil repellency of cotton fabrics treated with the FOM copolymers was better than that of conventional poly(fluoroalkyl acrylate)s containing the same fluorinated chain. The polymer films or the treated fabrics were characterized by Fourier transform infrared, scanning electron microscope, atomic force microscopy, thermogravimetric analysis, x-ray photoelectron spectrometry, and wide angle x-ray diffraction. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci, 2013
研究领域:
材料科学
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纺织化学
·
高分子化学
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DOI
高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2022
·
IF 6.76
Feihong Ye,Liping Li,Jianyin Xu,Lu Zhou
Synthesization of 1H,1H,2H,2H-Perfluorooctyltrimethoxysilane through solvent-free hydrosilylation of 1H,1H,2H-perfluoro-1-octene with trimethoxysilane was efficiently conducted over the RuCl 3 ·3H 2 O catalyst. The synergistic action of Ru 3+ as the active center and the strong electronegativity of Cl − to attract the electron of the electron-donating group –OCH 3 in trimethoxysilane, activated the Si-H and thus promoted the reaction. The influences of different reaction conditions including feed order, feed ratio, catalyst dosage, reaction temperature and reaction time on the reaction yield were fully investigated, to conclude the optimized condition to achieve a yield of 86.80% was the feed of 1.2 mol trimethoxysilane per mole of 1H,1H,2H-perfluoro-1-octene, together with the addition of 9.56 × 10 −4 mol RuCl 3 ·3H 2 O per mole of trimethoxysilane, at 80 °C for 4 h; while the additive of CuCl to RuCl 3 ·3H 2 O catalyst could further improve the reaction yield at 50℃. Finally, after understanding the activity of Ru with different valence state, the reaction mechanism was also proposed.
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
Analytical Methods
·
2018
·Vol. 10
·期 38
·4680-4688
·
IF 2.073
Yuxin Ma,Dandan Han,Yingjie Lei,Tao Zhu
A range of materials were synthesized based on different matrices of poly(styrene-divinylbenzene) (PS-DVB) and silica (Si). N-vinyl pyrrolidone (NVP) and 1H,1H,7H-dodecafluoroheptyl methacrylate (DMFA) were the functional monomers for the synthesis of PS-DVB–NVP, PS-DVB–NVP–DMFA, Si–NVP and Si–NVP–DMFA. The structures of the obtained materials were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, and Brunauer–Emmett–Teller and thermogravimetric analysis. The results demonstrated that NVP and DMFA can change the structure of the matrix pores. Using response surface methodology (RSM), the optimal proportion for synthesizing the materials was 330.00 μL of DMFA and 11.00 mg of AIBN at 80 °C. P–N–F showed the best recognition for pyrocatechin and quercetin, and the adsorption abilities were 12.14 μg mg−1 and 6.76 μg mg−1, respectively. In terms of applications, the method's recoveries of pyrocatechin and quercetin were in the range of 78.06–83.43% and 79.05–83.63% with associated intra-day relative standard deviations of less than 2.92% and 2.84%, respectively. P–N–F showed satisfactory results in that recoveries for pyrocatechin and quercetin were 83.43% and 83.63%, respectively. This showed potential for the rapid purification of flavonoids in an apple sample combined with dispersion solid-phase extraction (DSPE).
研究领域:
分析化学
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材料科学
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产品关联
DOI
高影响因子
Current Research in Food Science
·
2024
·
IF 6.2
Gui-Lin Hu,Chen-Xi Quan,Hao-Peng Dai,Ming-Hua Qiu
Defective coffee beans (DCB) are one of the main reasons for poor coffee quality. In the current research, chemical difference of three common DCB including sour beans (SCB), black beans (BCB), and mold beans (MCB) were clarified using 1 H qNMR method and compared with that of non-defective beans (NDCB). The results indicated that DCB has lower sugar and lipid content compared to NDCB, yet it boasts a higher acetate concentration. The 1 H NMR from water-soluble content was shown to be more effective than that of oil fraction for qualitative of DCB blends, regardless of whether partial least squares discriminant analysis (PLS-DA) or machine learning (ML) algorithms were used. Support vector machine (SVM) was proved to be excellent for distinguishing DCB blends. Finally, a partial least squares regression (PLS) model was built for quantitative analysis of DCB blends. In summary, current research will not only help to reveal the material basis of DCB and their impact on coffee flavor, but also provide feasible strategies for the identification of DCB.
研究领域:
食品科学
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分析化学
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产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2018
·Vol. 23
·期 3
·554
·
IF 3.098
Qianqian Liang,Qiuying Wang,Yuan Wang,Ya-nan Wang,Jia Hao,Miaomiao Jiang
The primary metabolites in aqueous extract of mulberry (Morus albaL.) leaves were characterized by using proton nuclear magnetic resonance (1H-NMR) spectroscopy. With the convenience of resonance assignment, GABA together with the other 10 primary metabolites was simultaneously identified and quantified in one1H-NMR spectrum. In this study, external calibration curves for metabolites were employed to calculate the concentrations of interests. The proposed quantitative approach was demonstrated with good linearity (r2ranged in the interval of 0.9965–0.9999), precision, repeatability, stability (RSD values in the ranges of 0.35–4.89%, 0.77–7.13% and 0.28–2.33%, respectively) and accuracy (recovery rates from 89.2% to 118.5%). The established1H-NMR method was then successfully applied to quantify 11 primary metabolites in mulberry leaves from different geographical regions within a rapid analysis time and a simple sample preparation procedure.Keywords:quantitative1H-NMR;Morus alba;amino acids;saccharides;organic acids
研究领域:
分析化学
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植物科学
·
代谢组学
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产品关联
DOI
PubMed
高影响因子
LIQUID CRYSTALS
·
2018
·
IF 2.636
Liyuan Ren,Longyan Duan,Qiang Weng,Pei Chen,Yafei Hou,Aiai Gao,Xinbing Chen,Zhongwei An
A series of 1-methyl-1H-benzimidazole-based compounds, 2-(4ʹ-alkoxy-1,1ʹ-biphenyl-4-yl)-1-methyl- 1H-1,3-benzimidazole derivatives (nPPMx-M) with terminal hydrogen, methyl and nitro moieties (coded as nPPMH-M, nPPMM-M and nPPMN-M, respectively), were prepared and their structures were characterised. The compounds display enantiotropic smectic mesophases for hydrogen and methyl terminated compounds (nPPMH-M and nPPMM-M), and enantiotropic nematic mesophases for nitro terminated compounds (nPPMN-M) with short alkoxy chain below than 10 carbon atoms, where the mesophase ranges are 24–72°C and 74–104°C on heating and cooling processes for nPPMH-M, 90–119°C and 110–135°C for nPPMM-M, and 102–129°C and 113–207°C for nPPMN-M, respectively. It is noted that the compounds nPPMx-M exhibit much lower melting points and much wider mesophase range both in heating and cooling than non-1-methyl substituted analogs, which are ascribed to the disruption of hydrogen bonding among the molecules caused by methyl substitution at 1-position of benzimidazole. Meanwhile, among the compounds nPPMx-M, much wider mesophase ranges are obtained for nPPMM-M and nPPMN-M, indicating a much high mesophase stability for the compounds bearing terminal moiety (CH3 and NO2).
研究领域:
材料化学
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物理化学
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DOI
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2020
·
IF 4.972
Shanshan He,Yanling Wang,Jianhua Xie,Heng Gao,Xiujiang Li,Zhibing Huang
Monascus comprises purple-red molds. Various compounds can be obtained from these species, including statins and food-safe yellow, red, and orange pigments. However, the secondary metabolite citrinin, a mycotoxin, is produced during the late stages of growth. Citrinin biosynthesis should be reduced to apply Monascus pigments safely. Fortunately, this can be achieved by the addition of flavonoids (genistein, daidzein, apigenin, and kaempferol). However, the effects of these flavonoids on other metabolites remain unknown. Here, we report a 1 H NMR-based multivariate metabolomic analysis of the effects of flavonoids on mycotoxin citrinin production by Monascus . Fifteen metabolites involved in lysine and arginine biosynthesis and alanine, aspartate, glutamate, biotin, arginine, proline, and glutathione metabolism were detected. The reduction in glutamate, aspartate, biotin, and 2-phosphoglycerate content suggested their association with the citrinin reduction mechanism. This study identifies the citrinin production pathway in Monascus and will aid in the development of citrinin-control methods.
研究领域:
微生物学
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代谢组学
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食品科学
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DOI
高影响因子
FOOD CHEMISTRY
·
2018
·
IF 4.946
MengTing Zhu,Ting Shi,Yi Chen,ShuHan Luo,Tuo Leng,YangLing Wang,Cong Guo,MingYong Xie
A rapid method for the determination of fatty acid (FA) composition in camellia oils was developed based on the 1 H NMR technique combined with partial least squares (PLS) method. Outliers detection, LVs optimization and data pre-processing selection were explored during the model building process. The results showed the optimal models for predicting the content of C18:1, C18:2, C18:3, saturated, unsaturated, monounsaturated and polyunsaturated FA were achieved by Pareto scaling (Par) pretreatment, with correlation coefficient ( R 2 ) above 0.99, the root mean square error of estimation and prediction (RMSEE, RMSEP) lower than 0.954 and 0.947, respectively. Mean-centering (Ctr) was more suitable for the model of C16:0 and C18:0 with the best performance indicators ( R 2 ≥ 0.945, RMSEE ≤ 0.377, RMSEP ≤ 0.212). This study indicated that 1 H NMR has the potential to be applied as a rapid and routine method for the analysis of FA composition in camellia oils.
研究领域:
食品科学
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分析化学
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产品关联
DOI
PubMed
高影响因子
Scientific Reports
·
2016
·Vol. 6
·期 1
·1-10
·
IF 5.228
Wu Haobo,Shen Jinyou,Wu Ruiqin,Sun Xiuyun,Li Jiansheng,Han Weiqing,Wang Lianjun
The highly recalcitrant 1H-1,2,4-triazole (TZ) is widely used in the synthesis of agricultural pesticide and considered to be an environmental pollutant. In this study, a novel strain NJUST26 capable of utilizing TZ as the sole carbon and nitrogen source, was isolated from TZ-contaminated soil, and identified as Shinella sp. The biodegradation assays suggested that optimal temperature and pH for TZ degradation by NJUST26 were 30 °C and 6–7, respectively. With the increase of initial TZ concentration from 100 to 320 mg L −1 , the maximum volumetric degradation rate increased from 29.06 to 82.96 mg L −1 d −1 , indicating high tolerance of NJUST26 towards TZ. TZ biodegradation could be accelerated through the addition of glucose, sucrose and yeast extract at relatively low dosage. The main metabolites, including 1,2-dihydro-3H-1,2,4-triazol-3-one (DHTO), semicarbazide and urea were identified. Based on these results, biodegradation pathway of TZ by NJUST26 was proposed, i.e., TZ was firstly oxidized to DHTO, and then the cleavage of DHTO ring occurred to generate N-hydrazonomethyl-formamide, which could be further degraded to biodegradable semicarbazide and urea.
研究领域:
环境微生物学
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生物修复
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有机化学
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产品关联
DOI
PubMed
高影响因子
LIQUID CRYSTALS
·
2020
·
IF 2.908
Jiazhen Dang,Shenghua Du,Liyuan Ren,Mengting Zhang,Pei Chen,Aiai Gao,Weisong Du,Xinbing Chen,Zhongwei An
Heterocyclic mesogenic compounds are one of the interesting liquid crystals. Here, a series of 1-methyl-1H- benzimidazole-based mesogenic compounds incorporating ethynyl moiety, 2-[4-[2-[4-(alkoxy)phenyl]ethynyl]phenyl]-1-methyl-1H-1,3-benzimidazole derivatives (nPEPMx) with terminal groups of H, CH3 and NO2 (coded as nPEPMH, nPEPMM and nPEPMN, respectively), are synthesised and their properties are evaluated. It is noted that the compounds nPEPMx with short alkoxy chain less than 9 carbon atoms display enantiotropic nematic mesophases, whereas corresponding reference compounds without ethynyl moiety have enantiotropic smectic mesophases. The mesophase ranges of compounds nPEPMx 50–70°C and 55–108°C on heating and cooling for nPEPMH, 76–106°C and 98–142°C for nPEPMM, and 78–132°C and 130–166°C for nPEPMN, respectively. Besides, compounds nPEPMx show obviously large birefringence of 0.501–0.641, suggesting a potential application in liquid crystal mixture. The high birefringence may result from its large π-conjugated molecule structure incorporating ethynyl and benzimidazole π-conjugated mesogenic unit.
研究领域:
材料化学
·
液晶科学
·
有机合成化学
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DOI
高影响因子
ANALYTICAL SCIENCES
·
2021
·Vol. 37
·期 10
·1413-1418
·
IF 2.081
Hua ZHAO,Xiaohui WANG,Yuli ZHANG,Xiaowan HUANG,Yaling JIANG,Huan MA,Li AN,Xujin WU,Qiang WANG
Saikosaponin a and saikosaponin d are used as chemical standards for the quality evaluation of Bupleurum chinense DC. by the high-performance liquid chromatography method in current Chinese Pharmacopoeia. However, other saikosaponins, such as saikosaponin c and saikosaponin b2, also possess pharmaceutical activity, but are not used as chemical standards. In this study, a quantitative proton nuclear magnetic resonance (1H NMR) method was developed to determine the total mass percentage (mg/g) of SSa, SSb1, SSb2 and SSd in B. chinense DC., using the H-24 (δH 0.71) signal. Furthermore, the molality (mol/kg) of type I saikosaponins (epoxy-ether structure) was also determined by quantitative 1H NMR in the area of H-11 (δH 5.95) for a more accurate quality evaluation. Validation of the method confirmed that it has acceptable selectivity, precision, stability, and repeatability. The results indicated that this method has the potential to be a reliable method for the quantification of saikosaponins in Bupleurum scorzonerifolium Willd., vinegar baked B. chinense DC. and B. scorzonerifolium Willd., Chaihu Koufuye (oral liquid of Chaihu).
研究领域:
药学化学
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分析化学
·
生药学
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产品关联
DOI
PubMed
高影响因子
CHINESE CHEMICAL LETTERS
·
2016
·
IF 1.947
Shi-Guo Zhang,Zong-Bo Xie,Lian-Sheng Liu,Meng Liang,Zhang-Gao Le
We discovered that α -chymotrypsin has a promiscuous ability to catalyze the cyclocondensation of aromatic and aliphatic aldehydes with 2-aminobenzamides to afford the corresponding 2,3-dihydroquinazolin-4(1 H )-ones successfully in high yields (90%–98%) under alcohol solvent. The catalytic activity of α -chymotrypsin was evaluated through investigating the temperature, the enzyme loading and the ratio of substrates in the enzyme-catalyzed reactions. The present method proves to be efficient and environmentally friendly in terms of short reaction time, high yield, green catalyst and the clean products obtained without further purification processes.
研究领域:
有机化学
·
生物催化
·
绿色化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）