BIORESOURCE TECHNOLOGY
·
2016
·
IF 4.917
Yu-Cai He,Zhi-Cheng Tao,Jun-Hua Di,Liang Chen,Lin-Bing Zhang,Dan-Ping Zhang,Gang-Gang Chong,Feng Liu,Yun Ding,Chun-Xia Jiang,Cui-Luan Ma
It was the first report that the concentrated hydrolyzates from the enzymatic hydrolysis of dilute NaOH (3 wt%)-soaking rice straw at 30 °C was used to form [Bmim]PF 6 -hydrolyzate (50:50, v/v) media for bioconverting ethyl 4-chloro-3-oxobutanoate (COBE) into ethyl ( R )-4-chloro-3-hydroxybutanoate [( R )-CHBE] (>99% e.e. ) with recombinant E. coli CCZU-A13. Compared with pure glucose, the hydrolyzates could promote both initial reaction rate and the intracellular NADH content. Furthermore, emulsifier OP-10 (20 mM) was employed to improve the reductase activity. Moreover, Hp-β-cyclodextrin (0.01 mol Hp-β-cyclodextrin/mol COBE) was also added into this bioreaction system for enhancing the biosynthesis of ( R )-CHBE from COBE by E. coli CCZU-A13 whole-cells. The yield of ( R )-CHBE (>99% e.e. ) from 800 mM COBE was obtained at 100% in the [Bmim]PF 6 -hydrolyzate (50:50, v/v) media by supplementation of OP-10 (20 mM) and Hp-β-CD (8 mM). In conclusion, an effective strategy for the biosynthesis of ( R )-CHBE was successfully demonstrated.
研究领域:
生物化学
·
微生物学
✓ 已验证
DOI
高影响因子
ORGANIC PROCESS RESEARCH & DEVELOPMENT
·
2018
·
IF 3.584
Juncheng Jiang,Fusheng Cui,Saili Shen,Xiuxia Guo,Lei Ni,Yong Pan
In this study, in order to assess thermal runaway risk of two step synthesis reactions, two new risk assessment methods were proposed by combining the new assessment procedure with the risk matrix and the Stoessel criticality diagram. The thermal runaway risks of the tert-butyl peroxybenzoate (TBPB) synthesis process and the tert-butyl peracetate (TBPA) synthesis process, and the influence of the use of the pure target products on the assessment results were also studied by the new methods. The results showed that the new methods could obtain more accurate assessment results of two step synthesis reactions. Some measures should be taken to reduce the thermal runaway risks of the two synthesis processes. Furthermore, the use of the pure target products in the new methods would exaggerate the thermal runaway risks of the two step synthesis reactions.
研究领域:
化学工程
·
安全科学
·
过程安全
✓ 已验证
DOI
高影响因子
CHEMICAL PAPERS
·
2019
·Vol. 74
·期 5
·1477-1486
·
IF 1.246
Zhou Feng,Zhang Jie,Xie Peng-fei,Li Yu
This work reports the relationship between monomer composition of typical acrylate copolymers and their oil absorption behaviors, considering the steric effects of isobornyl methacrylate (IBOMA) or reactive silica nanoparticles. With a molar ratio of stearyl acrylate (SA): butyl acrylate (BA): IBOMA = 1:1.2:0.3, the random copolymers exhibited absorbency of more than 30 mL/g for benzene, xylene, and other common fuel oils. The copolymers of SA and BA synthesized in the presence of 2% reactive silica nanoparticles (R-SiO 2 ) showed further improvement in oil absorbency, reaching 39.5 mL/g, 43.6 mL/g, and 40.7 mL/g for benzene, xylene, and CCl 4 , respectively. Compared to copolymers of SA and BA, copolymers formed using IBOMA or R-SiO 2 mainly hindered the diffusion of viscous oils such as kerosene or diesel, leading to decrease in absorption rate. All the prepared copolymers exhibited oil retention up to 99% for gasoline, kerosene, and CCl 4 after saturation of absorption, after centrifugation at 3000 rpm for 5 min, which is attractive for practical applications.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
POLYMER BULLETIN
·
2024
·Vol. 81
·期 11
·10351-10367
·
IF 3.1
Wang Guoqiang,Wu Yifan
Polylactic acid (PLA), which is widely used in degradable packaging and medicine, has attracted much attention in recent years. However, PLA's ductility and processability still need to be improved. Previous literature indicated that poly(butylene diglycolate-co-butylene terephthalate) (PBDT) had good ductility, and degradability due to the introduction of diglycolic acid's ether group. Based on the above advantages of PBDT, the PLA/PBDT blends were prepared to improve the ductility of PLA. The blends' thermal, crystallinity, mechanical, and rheological properties and compatibility were characterized. The blends all showed greater elongation at break compared to PLA. The WAXD results showed that the tensile specimens of PBDT were semi-crystalline, and the tensile specimens of PLA and the blends were almost amorphous. The incorporation of PBDT caused the fracture behaviour of the blends to change from brittle to ductile behaviour. It is concluded that PBDT can effectively improve the ductility of PLA and the blend with 20 wt.% PBDT has high elongation at break (135%).
研究领域:
材料科学
·
高分子科学
·
生物降解材料
·
大分子化学
✓ 已验证
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2020
·Vol. 35
·期 1
·e6073
·
IF 3.14
Jianyu Dong,Xiuling Chen,Fangyan Ji,Lixin Liu,Lebin Su,Min Mo,Jian-Sheng Tang,Yongbo Zhou
A simple and direct aerobic oxidative esterification reaction of arylacetonitriles with alcohols/phenols is achieved in the presence of a copper salt and molecular oxygen, which produces a broad range of aryl carboxylic acid esters in good to high yields. Copper salt plays multiple roles in the transformation, which allows the oxygenation of C H bond, cleavage of inert C C bond, and formation of C O bond in one pot without the assistance of any of the acids, bases, ligands, and so on. The reaction provides a simple, direct, and efficient protocol towards functionalized esters, especially aryl benzoates, from readily available starting materials.
研究领域:
有机化学
·
合成化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ANALYTICAL CHEMISTRY
·
2020
·Vol. 75
·期 3
·330-342
·
IF 0.84
Haishuang Jia,Liu Wenfang,Li Na,Wang Jun,Song Youtao
Abstract Two novel methods for spectrophotometric determination of Cu 2+ ion using synthesized and characterized furfuraldehyde fluorescein diacetate hydrazone ( FFDH ) and furfuraldehyde fluorescein hydrazone ( FFH ) have been proposed. Addition of Cu 2+ to FFDH and FFH solutions results in a rapid color change from colorless to dark yellow. Experimental results show that FFH and FFDH both can provide a rapid, selective and sensitive response to Cu 2+ within a linear dynamic range of 7–33 µM and the detection limits of 1.1 × 10 –7 and 7 × 10 –8 M, respectively. Apparently, the detection limit of FFDH is lower than that of FFH, which indicates that FFDH forms a more stable complex with Cu 2+ . In addition, the detection of Cu 2+ in water samples was also studied; as a result, the developed FFDH was found to be more applicable than FFH for spectrophotometric determination of Cu 2+ in environmental water samples. Particularly, as a lipid chemical compound, FFDH may be transported across the cell membrane to detect Cu 2+ in vivo. It is of great significance in many fields, such as biology, biochemistry, medicine and environment.
研究领域:
分析化学
·
环境科学
·
生物化学
✓ 已验证
DOI
高影响因子
WATER RESEARCH
·
2015
·
IF 5.528
Zhaobing Li,Zhi Chen,Yingying Xiang,Li Ling,Jingyun Fang,Chii Shang,Dionysios D. Dionysiou
Bromate formation in bromide-containing water through the cobalt (Co)-mediated activation of peroxymonosulfate (PMS) was investigated. Increasing the PMS dosage and the cobalt dosage increased the formation of bromate and bromate yields of up to 100% were recorded under the test conditions. The bromate yield increased to a maximum as the pH rose from 2.7 to 6 before decreasing by over 90% as the pH rose further from 6 to above 9. The bromate formation is a two-step process involving free bromine as a key intermediate and bromate as the final product. In the first step, apart from the known oxidation of bromide to free bromine and of free bromine to bromate by sulfate radicals (SO 4 − ), Co(III) produced from the oxidation of Co(II) by PMS and SO 4 − also oxidizes bromide to free bromine. The contribution of Co(III) to the bromate formation was verified with the addition of methanol and EDTA, a radical scavenger and a Co(III) ligand, respectively. In the presence of methanol, free bromine formation increased with increasing Co(II) dosage but no bromate was detected, indicating that Co(III) oxidized bromide to form free bromine but not bromate. In the presence of both EDTA and methanol, no free bromine or bromate was detected, as Co(III) was stabilized by EDTA to form the Co III EDTA – complex, which could not oxidize bromide. Mathematical simulation further suggested that Co(III) outweighed SO 4 − to oxidize bromide to free bromine. On the other hand, SO 4 − is essential for the oxidation of free bromine to bromate in the second step. In real water, the presence of NOM significantly decreased the bromate formation but caused the brominated organic DBP formation with high quantity. This is the first study to demonstrate the significant bromate formation in the Co/PMS system and the substantial contribution of Co(III) to the formation.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
PubMed
高影响因子
Journal of Materials Chemistry B
·
2013
·Vol. 2
·期 10
·1344-1353
·
IF 0
Dongsheng Tan,Zhen Li,Xuelin Yao,Chunlan Xiang,Hong Tan,Qiang Fu
To study the influence of fluorinated surfaces and biomimetic surfaces on the improvement of the blood compatibility of polymers, three monomers containing a fluorinated tail and/or phosphorylcholine groups were designed and synthesized, and were then introduced into polyurethanes based on 4,4′-diphenylmethane diisocyanate (MDI), poly(tetramethylene glycol) (PTMG) and 1,4-butanediol (BDO) via end-capping. The bulk and surface characterization of the polyurethanes was carried out by dynamic mechanical analysis (DMA), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopic analysis (XPS), atomic force microscope (AFM), and water contact angle measurements. The results indicate that the fluorocarbon chains can drive the phosphorylcholine groups to aggregate at the surface of polyurethane, and the two components show spontaneous arrangement to adapt to the environment when in contact with water. The preliminary evaluation of hemocompatibility was carried out via fibrinogen adsorption and platelet adhesion. The fluorocarbon chains and phosphorylcholine groups showed a synergistic effect on the improvement of hemocompatibility.
研究领域:
生物材料学
·
医学工程
✓ 已验证
DOI
PubMed
HIGH PERFORMANCE POLYMERS
·
2020
·
IF 1.568
Xing-Hua Guan,He-Ran Nie,Hong-Hua Wang,Ji-Yong Zhao,Zhi-Peng Wang,Rui Wang,Bao-Feng Liu,Guang-Yuan Zhou,Qiang Gu
A series of aromatic polyesters bearing fluorene and phthalein groups were synthesized from commercially available 9,9-bis(4-hydroxyphenyl)fluorene (BPF), phenolphthalein, and terephthaloyl chloride through an interfacial polymerization method. The microstructure, molecular weight, morphology, thermal properties, and thermal decomposition mechanism of these aromatic polyesters were investigated. Their mechanical properties were also evaluated. The results suggested that the copolymer compositions were approximately equal to the feed compositions. Moreover, the increase in the BPF unit content increased the glass transition and weight loss temperatures of the aromatic polyesters, owing to the strong rigidity of the bulky fluorene group. All the polymers were amorphous and exhibited good solubility in common organic solvents. Hence, the synthesized polymers could be easily cast into flexible films. The copolymer film samples exhibited better mechanical properties than those of the homopolymers. The tensile strength, Young’s modulus, and elongation at break of the polymers first increased gradually, and then decreased with increasing BPF content. Notably, the copolymers exhibited the best mechanical properties at the BPF content range 30–50%. Owing to their characteristics, these synthesized polymers show great potential for application as high performance membrane materials.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
Coatings
·
2017
·Vol. 7
·期 10
·159
·
IF 2.175
Shaolong Li,Changlian Xu,Wenfeng Yang,Qingru Tang
We report an efficient and green approach to synthesize a linear castor oil-based polyurethane (CPU) without using any solvent or catalyst. Diol monomers were first synthesized by the aminolysis reaction between castor oil and diamines; this was accomplished within 6 h at 130 °C. Polymerization of the diols and isocyanate was further confirmed by Fourier transform infrared (FTIR),1H-nuclear magnetic resonance (1H-NMR), and gel permeation chromatography analyses. The resultant CPUs showed a good thermal stability with an initial degradation temperature higher than 300 °C, and their mechanical and wood bonding property can be modulated by the structures of diamine. In addition, the CPUs possessed a satisfying water resistance property with the water absorption amount lower than 2%. The green conversion of castor oil to thermoplastic polyurethane affords new opportunities in bio-based industries.Keywords:castor oil;linear polyurethane;catalyst-free;solvent-free
研究领域:
材料科学
·
绿色化学
✓ 已验证
DOI
高影响因子
ChemCatChem
·
2015
·Vol. 7
·期 8
·1372-1379
·
IF 4.556
Xing Tang,Xianhai Zeng,Zheng Li,Weifeng Li,Yetao Jiang,Lei Hu,Shijie Liu,Yong Sun,Lu Lin
Graphical In situ generated catalyst system: HCl/ZrO(OH) 2 catalysts are prepared in situ by the autonomous decomposition of ZrOCl 2 ⋅ 8 H 2 O in levulinic acid (LA)/2-butanol solution. The esterification of LA was catalyzed in tandem with hydrocyclization to γ-valerolactone (GVL) by Meerwein–Ponndorf–Verley reduction. This is the first report of HCl/ZrO(OH) 2 catalysts prepared in situ by the autonomous decomposition of ZrOCl 2 ⋅ 8 H 2 O in levulinic acid (LA)/2-butanol solution, which catalyzed the esterification of LA in tandem with hydrocyclization to γ-valerolactone (GVL) by Meerwein–Ponndorf–Verley (MPV) reduction without the use of external H 2 . A maximum GVL yield of 92.4 % from neat LA and a GVL formation rate of 1092.2 μmol g −1 min −1 were achieved in 2-butanol at 240 °C in 2 h. The in situ generated ZrO(OH) 2 was characterized comprehensively and its unexpected catalytic efficiency was attributed mainly to its extremely high surface area. A crude LA stream from the acid hydrolysis of cellulose was extracted into 2-butanol and subjected to this catalyst system to give a GVL yield of 82.0 % even in the presence of humins.
研究领域:
化学工程
·
可再生能源
·
催化化学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2017
·
IF 4.339
Zhixiong Luo,Somboon Chaemchuen,Kui Zhou,Andres Alvarado Gonzalez,Francis Verpoort
A series of metal organic frameworks (MOFs) MDABCO (M = Co, Ni, Cu, Zn; DABCO = 1,4-diazabicyclo[2.2.2]octane) are utilized as catalysts for the bulk ring-opening polymerization of l -lactide. The catalytic activity varies in the order CuDABCO, NiDABCO < ZnDABCO, CoDABCO. By adding lactic acid, we unexpectedly observed enhanced catalytic activity. The combined use of lactic acid and ZnDABCO during polymerization results in a highly active polymerization system, along with the gradual change of MOFs structure caused by an increased acid concentration. Compared to related homogeneous fragments, such as zinc nitrate and 1,4-diazabicyclo[2.2.2]octane, ZnDABCO is found to afford highly isotactic polylactide, which would be ascribed to the unique structural properties of MOFs.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）