COMPOSITES SCIENCE AND TECHNOLOGY
·
2018
·
IF 5.16
Wei Wu,Haibing He,Tao Liu,Ruichao Wei,Xianwu Cao,Qijun Sun,Shishir Venkatesh,Richard K.K. Yuen,Vellaisamy A.L. Roy,Robert K.Y. Li
Lignin can be employed as a sustainable functional additive and reinforcement filler for polymers. In this work, melamine phosphate modified lignin (MAP-lignin) was synthesized as a bio-based halogen-free flame-retardant agent. The synergetic effects between MAP-lignin and rice husk ash (RHA) on the thermal stability, dynamic mechanical performance and flame-retardant properties of the poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB) biocomposites were investigated. The results revealed that MAP-lignin and RHA could significantly increase the char residue and MAP-lignin had a good miscibility with P34HB. The incorporation of MAP-lignin and RHA as stiff fillers could enhance the storage modulus of the P34HB matrix. Moreover, the tensile strength and elongation at break of the P34HB/RHA composite could be improved due to the MAP-lignin could serve as a compatibilizer to improve the interaction between RHA and P34HB. Cone calorimetry data demonstrated that the addition of 30 wt% MAP-lignin and 5 wt% RHA reduced the peak heat release rate ( PHRR ) and total heat release ( THR ) of P34HB noticeably by 42.8 and 24.3%, respectively. In addition, the CO 2 production rate and CO concentration could be significantly suppressed by the addition of MAP-lignin. The enhanced flame retardancy of P34HB composite should be ascribed to the barrier effect of the increased char residue with compact and intact structure, as well as the released gases from the decomposition of melamine.
研究领域:
材料科学
·
生物工程
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产品关联
DOI
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2016
·Vol. 181
·期 4
·1347-1359
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IF 1.606
Dai Yong,Huan Bin,Zhang Hai-Sheng,He Yu-Cai
To increase the biocatalytic activity of Escherichia coli CCZU-T15 whole cells, choline chloride/glycerol ([ChCl][Gly]) was firstly used as biocompatible solvent for the effective biotransformation of ethyl 4-chloro-3-oxobutanoate (COBE) into ethyl ( S )-4-chloro-3-hydroxybutanoate [( S )-CHBE]. Furthermore, L-glutamine (150 mM) was added into [ChCl][Gly]–water ([ChCl][Gly] 12.5 vol%, pH 6.5) media instead of NAD + for increasing the biocatalytic efficiency. To further improve the biosynthesis of ( S )-CHBE (>99 % e.e. ) by E. coli CCZU-T15 whole cells, Tween-80 (7.5 mM) was also added into this reaction media, and ( S )-CHBE (>9 % e.e. ) could be effectively synthesized from 2000 and 3000 mM COBE in the yields of 100 and 93.0 % by whole cells of recombinant E. coli CCZU-T15, respectively. TEM image indicated that the cell membrane was permeabilized and lost its integrity and when the cell was exposed to [ChCl][Gly]–water media with Tween-80. Clearly, this bioprocess has high potential for the effective biosynthesis of ( S )-CHBE (>99 % e.e. ).
研究领域:
生物化学
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合成生物学
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产品关联
DOI
PubMed
高影响因子
BIORESOURCE TECHNOLOGY
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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
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微生物学
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DOI
高影响因子
ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY
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2020
·Vol. 40
·期 1
·72-78
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IF 3.152
Huiyan Tong,Xingshuai Hu,Xiaocong Zhong,Qianyi Jiang
Biodegradable plastics have been increasingly used as a solution to the problem of plastic pollution in recent years. However, there are few studies on the negative effects of biodegradable microplastics. Triclosan, a widely used disinfectant, is a highly toxic substance. In the present study, the adsorption and desorption processes of triclosan on a type of biodegradable plastics, polyhydroxybutyrate (PHB), were investigated and also compared with one conventional plastic type, polyethylene. The adsorption equilibrium quantities of polyethylene and PHB were 3431.85 and 9442.27 μg/g, respectively. The adsorption rate and equilibrium adsorption capacity of triclosan on PHB are much higher than on polyethylene. Physical adsorption of triclosan on PHB and polyethylene microplastics may play a dominant role in this process. The desorption hysteresis indices are all less than zero; this indicates that triclosan is easily released from PHB and polyethylene microplastics under physiological conditions. Our results indicate that biodegradable PHB microplastics are stronger carriers for triclosan than the conventional polyethylene microplastics in the aquatic environment. Environ Toxicol Chem 2021;40:72–78. © 2020 SETAC
研究领域:
环境科学
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毒理学
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产品关联
DOI
PubMed
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2024
·
IF 7
Rui Wang,Yi Zeng,Jiaqian Liang,Huixin Zhang,Junjie Yi,Zhijiia Liu
Fermented vegetables are known for their unique flavors and aromas, which are influenced by the complex microbial processes that occur during fermentation. Rhodotorula mucilaginosa is a red yeast strain that is frequently isolated from fermented vegetables. However, the specific mechanisms underlying their effects on aroma production remain unclear. In this study, a simulated system of vegetables fermented using vegetable juices was used to investigate the effects of R. mucilaginosa inoculation on aroma development. The results demonstrated that this red yeast strain could utilize the nutrients present in the vegetable juices to support its growth and reproduction. Moreover, the inoculation of fermented vegetable juices with this yeast strain led to an increase in the levels of umami amino acids and sweet amino acids. Furthermore, this yeast strain was found able to significantly reduce the content of sulfur-containing compounds, which may decrease the unpleasant odor of fermented vegetables. Additionally, the yeast strain was capable of producing high concentrations of aromatic compounds such as phenylethyl alcohol, methyl 2-methylbutyrate, methyl butyrate, and nonanoic acid in a minimum medium. However, only phenylethyl alcohol has been identified as a core aromatic compound in fermented vegetable juice. The three fermented vegetable juices exhibited significantly different flavor profiles according to comparative analysis. Therefore, the core flavor compounds found in fermented vegetables are primarily derived from the release and modification of endogenous flavors naturally present in the vegetables, facilitated by the yeast during fermentation.
研究领域:
食品科学
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微生物学
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风味化学
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产品关联
DOI
PubMed
高影响因子
Biomedical Materials
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2020
·Vol. 15
·期 4
·045023
·
IF 3.174
Fanchen Sun,Jing Guo,Yuanfa Liu,Yue Yu
In this study, hydrophilic pullulan, which is favorable for cell adhesion, proliferation, and differentiation, was selected as a modifier for the preparation of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-co-4HB))/pullulan nanofibers via electrospinning to improve the biocompatibility of P(3HB-co-4HB) and increase the drug loading of composite fibers. Alkyl polyglycoside was used as the emulsifying agent to promote emulsification and stabilize the P(3HB-co-4HB)/pullulan composite solution. Drug-loading property of the nanofibers with a shell-core structure is increased because gelatin was not formed into fibers via electrospinning, thereby forming a stable drug-containing gelatin solution in the core layer. Finally, P(3HB-co-4HB)/pullulan-gelatin shell-core nanofibers were prepared. The intermolecular interaction, morphology, crystallization properties, mechanical properties, morphology, sustained release, and biocompatibility of composite nanofibers were characterized. Results show that the crystallization property of P(3HB-co-4HB)/pullulan composite nanofibers increases continuously with an increase in the pullulan content. As the pullulan content increases, the strain and stress of P(3HB-co-4HB)/pullulan nanofibers increase initially and decrease later. At the mass ratio of P(3HB-co-4HB) to pullulan of 10:2, P(3HB-co-4HB)/pullulan composite nanofibers exhibit a uniform morphology with an average diameter of 590 nm and porosity of 70.71%. At this mass ratio, the P(3HB-co-4HB)/pullulan-gelatin/drug shell-core structure, which sustained a release effect for more than 180 h, has potential applications as biomaterials without cytotoxicity.
研究领域:
材料科学
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生物医学工程
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药学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2016
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IF 1.835
Jun Gao,Hong Li,Dongmei Xu,Lianzheng Zhang,Liwen Zhao,Chunlu Li
The isobaric vapor–liquid equilibrium (VLE) data for the systems (thioglycolic acid + water), (thioglycolic acid + butyl acetate), (thioglycolic acid + butyl formate), and (thioglycolic acid + isobutyl acetate) were measured at P = 101.3 kPa by using a vapor recirculating type (modified Rose) equilibrium still. The thermodynamic consistency test of the experimental data for the four binary systems were confirmed by the method of Van Ness. The experimental VLE data were correlated by the three activity coefficient models of Wilson, nonrandom two-liquid (NRTL), and universal quasi-chemical (UNIQUAC). The results show that all the calculated data by the Wilson, NRTL, and UNIQUAC models are in good agreement with the measured VLE data. Meanwhile, the binary interaction parameters of the three models for the binary systems were regressed.
研究领域:
化学工程
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热力学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
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2021
·Vol. 22
·期 16
·8668
·
IF 5.924
Jie Li,Shiyi Wang,Huayin Li,Yuan Tan,Yunjie Ding
The synthesis of ester compounds is one of the most important chemical processes. In this work, Zn-Mg-Al mixed oxides with different Zn2+/Mg2+molar ratios were prepared via co-precipitation method and supported gold nanoclusters to study the direct oxidative esterification of aldehyde and alcohol in the presence of molecular oxygen. Various characterization techniques such as N2-physical adsorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and CO2temperature programmed desorption (TPD) were utilized to analyze the structural and electronic properties. Based on the results, the presence of small amounts of Zn2+ions (~5 wt.%) provoked a remarkable modification of the binary Mg-Al system, which enhanced the interaction between gold with the support and reduced the particle size of gold. For oxidative esterification reaction, the Au25/Zn0.05MgAl-400 catalyst showed the best performance, with the highest turnover frequency (TOF) of 1933 h−1. The active center was believed to be located at the interface between metallic gold with the support, where basic sites contribute a lot to transformation of the substrate.Keywords:gold catalyst;cluster;hydrotalcite;oxidative esterification;methyl isobutyrate
研究领域:
化学工程
·
催化材料
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DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
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2024
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IF 10.7
Xinyi Chen,Yitong Ding,Mingjiao Li,Hao Wu,Ze Kan,Zhibo Li
Chemically synthesized poly(4-hydroxybutyrate) (P4HB) is a new generation of biomass-derived and degradable semi-crystalline polymer with good comprehensive properties, but high costs limit its application. Starch, as an inexpensive natural polymer , can reduce the cost of P4HB products. However, starch lacks thermoplastic behavior and has poor compatibility with P4HB, thus its extensive use will inevitably impair the mechanical properties of P4HB. In this study, the ball-milling starch grafting process is adopted, which can simultaneously solve the two major deficiencies of starch, and the prepared ball-milling starch-g-polycaprolactone (BSt-g-PCL) has thermoplasticity and better compatibility with P4HB. BSt-g-PCL can melt near 55 °C, and the interweaving of its molecular chains with P4HB reduces the binding energy ( E interaction ) of both, making the phase interface blurred or even disappear. Therefore, the elongation at break retention ( R EB ) of P4HB/BSt-g-PCL can increase from 37.1 % to 74.3 % compared to P4HB/starch at the same filling (70 Phr). Additionally, BSt-g-PCL can exert the effect of accelerating P4HB degradation and still make it maintain excellent anti-aging ability. The ball-milling starch graft process provides a simple and effective method for the preparation of inexpensive fully biodegradable P4HB composite films with excellent mechanical properties.
研究领域:
材料科学
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生物工程
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产品关联
DOI
PubMed
高影响因子
RESEARCH ON CHEMICAL INTERMEDIATES
·
2019
·Vol. 46
·期 2
·1469-1485
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IF 2.064
Yu Xin,Peng Lincai,Pu Qiuyu,Tao Ruili,Gao Xueying,He Liang,Zhang Junhua
The preparation and application of biorenewable carbon-based catalyst are attracting increasingly attention in the field of green and sustainable chemistry. Here, a facile and low-cost lignosulfonate-based carbonaceous solid acid (LSS) was availably prepared via directly sulfonating lignosulfonate that was from sulfite pulping industry, and used to catalyze biomass-derived furfuryl alcohol to yield versatile butyl levulinate. The fabrication and properties of LSS were highly sensitive to the sulfonation conditions (i.e., lignosulfonate-to-H 2 SO 4 ratio and temperature). The physicochemical properties of the as-prepared LSS were well characterized using BET surface area, acid–base titration, SEM, XRD, FT-IR, XPS, and TGA techniques. The LSS contained –SO 3 H, –COOH and phenolic –OH groups and was ideal to perform the reaction of furfuryl alcohol with n-butanol to obtain butyl levulinate in yield higher than 95% at 110 °C for 8 h with catalyst dosage of 15 g/L. Meanwhile, the catalyst deactivated increasingly with a recycle number that was attributed to the adsorption of formed polymeric by-products on the active catalyst sites, and the slightly deactivated catalyst after plain sulfonation treatment was found to remain active with an almost unchanged product yield in consecutive cycles. This work highlights an economic, eco-friendly, sustainable and promising protocol for catalytic upgrading of bio-based compounds.
研究领域:
绿色化学
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可再生资源利用
·
催化化学
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产品关联
DOI
高影响因子
CHINESE JOURNAL OF CHEMICAL PHYSICS
·
2021
·Vol. 34
·期 1
·102-111
·
IF 1.114
Qian Si-yu,Feng Bei-bei,Zhai Yi-tong,Zhao Wei,Wang Lei,Ao Cheng-cheng,Liu Yi,Liu Jing,Zhang Li-dong
To obtain insight into the catalytic reaction mechanism of biodiesels over ZSM-5 zeolites, the pyrolysis and catalytic pyrolysis of methyl butanoate, a biodiesel surrogate, with H-type ZSM-5 (HZSM-5) were performed in a flow re-actor under atmospheric pressure. The pyrolysis products were identified and quantified using gas chromatography-mass spectrometry (GC-MS). Kinetic modelling and experimental results revealed that H-atom abstraction in the gas phase was the primary pathway for methyl butanoate decomposition during pyrolysis, but dissociating to ketene and methanol over HZSM-5 was the primary pathway for methyl butanoate consumption during catalytic pyrolysis. The initial decomposition temperature of methyl butanoate was reduced by approximately 300 K over HZSM-5 compared to that for the uncatalyzed reaction. In addition, the apparent activation energies of methyl butanoate under catalytic pyrolysis and homogeneous pyrolysis conditions were obtained using the Arrhenius equation. The significantly reduced apparent activation energy confirmed the catalytic performance of HZSM-5 for methyl butanoate pyrolysis. The activation temperature may also affect some catalytic properties of HZSM-5. Overall, this study can be used to guide subsequent catalytic combustion for practical biodiesel fuels.
研究领域:
能源科学
·
催化化学
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DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2018
·
IF 2.631
Qian Zeng,Biao Hu,Hongye Cheng,Lifang Chen,Junmei Huang,Zhiwen Qi
Isobutyl isobutyrate is an important chemical which can be formed in a reactive extraction process with ionic liquid as dual solvent-catalyst. To design such an intensified process, the liquid-liquid equilibria (LLE) data for the esterification system involving ionic liquid are essential. In this work, the LLE of ternary systems {isobutyl isobutyrate (IBIBE) + isobutyric acid (IBAc) or isobutanol (IBOH) + 1-butyl-3-methylimidazolium hydrogen sulfate ([BMIm][HSO 4 ])} and the quinary system {IBAc + IBOH + IBIBE + H 2 O + [BMIm][HSO 4 ]} were measured at temperature T = (298.2, 323.2 and 353.2) K, T = (323.2, 333.2, 343.2 and 353.2) K and atmospheric pressure, respectively. Based on the experimental data, the solute distribution coefficient and the selectivity were determined, which confirms the feasibility of the ionic liquid for isobutyl isobutyrate formation. The phase behaviour was explained by the molecular interaction using σ -potential analysis. Moreover, the binary parameters of the NRTL model for [BMIm][HSO 4 ] catalysed isobutyl isobutyrate formation system were fitted.
研究领域:
化学工程
·
物理化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）