ACS Sustainable Chemistry & Engineering
·
2017
·
IF 5.951
Xueyan Zhang,Yue Li,Lifang Xue,Shengtian Wang,Xiaohong Wang,Zijiang Jiang
A series of Lewis acid metals monosubstituted phosphotungstic acids HnPW11MO39 (HPWM, M = CuII, ZnII, CrIII, FeIII, SnIV, TiIV, and ZrIV; for Ti and Zr, the number of oxygen is 40) was evaluated in direct production of methyl levulinate (ML) from cellulosic biomass in a cascade reaction. One of the solid catalysts, H5PW11TiO40 (HPWTi), was found to be highly efficient for generation of ML from mono- or polysaccharides, reaching 51.3% ML yield directly from cellulose. And under microwave-assistance, the efficiency could be improved to a 62.6% ML yield within 2 h, which was almost the best result so far among reported solid catalysts. Identification of the reaction intermediates and the products provided some insight into the reaction mechanism and showed the requirement of certain Brønsted/Lewis acid ratio as 2.84/1 for HPWM. Moreover, the different metals in catalysts profoundly affected the Lewis or total acidity, and therefore, the catalytic activity and selectivity to ML or methyl glucosides (MG). HPWTi acted as a heterogeneous catalyst after being calcinated at 200 °C and showed high recyclability with minor loss of performance.
研究领域:
化学工程
·
生物质能
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产品关联
DOI
高影响因子
JOURNAL OF EXPERIMENTAL BIOLOGY
·
2014
·Vol. 217
·期 19
·3512-3518
·
IF 3.002
Li Jianjun,Wang Zhengwei,Tan Ken,Qu Yufeng,Nieh James C.
Social pollinators such as honey bees face attacks from predators not only at the nest, but also during foraging. Pollinating honey bees can therefore release alarm pheromones that deter conspecifics from visiting dangerous inflorescences. However, the effect of alarm pheromone and its chemical components upon bee avoidance of dangerous food sources remains unclear. We tested the responses of giant honey bee foragers, Apis dorsata , presented with alarm pheromone at a floral array. Foragers investigated the inflorescence with natural alarm pheromone, but 3.3-fold more foragers preferred to land on the ‘safe’ inflorescence without alarm pheromone. Using gas chromatography–mass spectrometry analysis, we identified eight chemical components in the alarm pheromone, of which three components (1-octanol, decanal and gamma-octanoic lactone) have not previously been reported in this species. We bioassayed six major compounds and found that a synthetic mixture of these compounds elicited behaviors statistically indistinguishable from responses to natural alarm pheromone. By testing each compound separately, we show that gamma-octanoic lactone, isopentyl acetate and (E)-2-decen-1-yl acetate are active compounds that elicit significant alarm responses. Gamma-octanoic lactone elicited the strongest response to a single compound and has not been previously reported in honey bee alarm pheromone. Isopentyl acetate is widely found in the alarm pheromones of sympatric Asian honey bee species, and thus alarmed A. dorsata foragers may produce information useful for conspecifics and heterospecifics, thereby broadening the effects of alarm information on plant pollination.
研究领域:
昆虫学
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化学生态学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2018
·
IF 6.735
Shuolin Zhou,Xianxiang Liu,Jinhua Lai,Min Zheng,WenZhu Liu,Qiong Xu,Dulin Yin
A novel inorganic-organic hybrid nanocatalyst has been prepared by initially functionalizing titanate nanotubes with 3-amino-propyltrimethoxysilane and subsequently introducing sulfonic acid groups with 1,4-butane-sultone. The as-prepared hybrid catalyst was characterized by FT-IR, XRD, TEM, SEM-EDX, TG-DTG, and N 2 adsorption isotherm techniques, and its catalytic performance was evaluated by esterification of levulinic acid with n -butyl alcohol under solvent-free conditions. The experimental design and study were carried out by response surface methodology (RSM) to test the effects of reaction conditions on the catalytic process. Up to 82.7% yield of n -butyl levulinate was obtained under the optimal reaction conditions. Furthermore, the catalyst showed an excellent reusability without the loss of reactivity after several runs.
研究领域:
材料科学
·
催化化学
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产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2017
·
IF 2.323
Feng Zhou,Lei Zhong,Changxu Chen,Ye Li,Chunjian Xu
Isobaric vapor–liquid equilibrium (VLE) data for binary systems of isoamyl alcohol + dimethyl sulfoxide (DMSO) and isoamyl acetate + DMSO, and the ternary system of isoamyl alcohol+ isoamyl acetate + DMSO at 101.33 kPa were measured by a modified Rose-Williams equilibrium still. The binary experimental data were checked by Herington method and a Van Ness test to verified thermodynamic consistency. The ternary VLE data was checked by Van Ness test. The experimental measurements of the binary systems were correlated by Wilson, nonrandom two-liquid (NRTL) and universal quasichemical (UNIQUAC) activity coefficient models with minor deviation. The ternary VLE data predicted by the obtained correlation parameters fit well with the experimental data. The experimental results indicate that the relative volatility between isoamyl alcohol and isoamyl acetate is changed obviously with the addition of DMSO as an entrainer at 0.50 mass fraction, which shows DMSO is an effective solvent for the separation of isoamyl alcohol and isoamyl acetate mixture in extractive distillation.
研究领域:
化学工程
·
热力学
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产品关联
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 25
·15054-15059
·
IF 3.361
Miaojia Song,Xiaohui Di,Yu Zhang,Yongming Sun,Zhongming Wang,Zhenhong Yuan,Ying Guo
As an important bio-based chemical, methyl levulinate (ML) can be produced via enzymatic esterification of levulinic acid with methanol. A kinetic model is developed in this work based on the law of mass action and reaction reversibility, to investigate the effect of enzyme loading, alcohol/acid ratio and temperature on ML yield. Data analysis shows that newly developed binary regression is apparently more persuasive than the commonly used unitary regression. Kinetic study reveals: (1) rate constants of esterification/hydrolysis increase with increasing enzyme loading, while their ratio (equilibrium constant) remains invariant. (2) Methanol has no toxicity towards lipase, and hence, neither the rate constants of esterification/hydrolysis nor the equilibrium constant are affected by alcohol/acid ratio. (3) Both rate constants of esterification/hydrolysis and the equilibrium constant increase with temperature elevation, and their relationships agree with Arrhenius equation and Van't Hoff equation, respectively. (4) The esterification is endothermic and spontaneous. In total, the application of binary regression analysis for the developed model to study the enzymatic esterification kinetics is quite successful.
研究领域:
生物化学
·
酶工程
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DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2017
·
IF 9.446
Lingyun Jiang,Lipeng Zhou,Jinyu Chao,Huiting Zhao,Tianliang Lu,Yunlai Su,Xiaomei Yang,Jie Xu
Conversion of biomass derived carbohydrates to alkyl levulinates is an important process due to the wide application of alkyl levulinates as chemicals and biofuel additives. Efficient conversion of cheap and abundant glucose to alkyl levulinates over easily separated and regenerated solid catalyst is highly desirable. Here, the transformation of glucose to methyl levulinate (MLE) was studied over dual solid acid catalysts. The synergistic effect of solid Brønsted (B) acid and solid Lewis (L) acid was observed. A combined catalyst system consisting of both B acid and L acid was found to be more efficient for the production of MLE from glucose. 62% yield of MLE was given over the combined catalyst of SO 4 2− /ZrO 2 and Sn-Beta prepared by postsynthesis method at 170 °C for 24 h. The roles of L acid sites of SO 4 2− /ZrO 2 and Sn-Beta, and B acid sites of SO 4 2− /ZrO 2 were discussed in detail. Alternative biomass-derived carbohydrates also gave moderate to good yields of MLE. Recyclability studies indicated that the combined catalyst system can be reused without significant change in the yield of MLE, proving its easy recovery and thermal stability during regeneration.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2025
·
IF 13.1
Ruiqi Fang,Jie Kang,Fengliang Wang,Xin Zhao,Yingwei Li
The production of valerate esters, a class of transportation biofuels (additives), usually undergoes alternate hydrogenation and acid-catalysis dehydration processes that suffer from inevitable coke deposition and undesirable side reactions. We report a one-pot esterification–hydrogenolysis reaction pathway for valeric biofuels synthesis from biomass-derived 2-furoic acid, which was proceeded over the elaborate CoPtX@Co3O4-NC (X = 0.01, 0.02, 0.05, and 0.1) catalysts. The catalysts were constructed through a MOF-engaged etching-pyrolysis-replacement strategy to obtain mesoporous pocket cube nanoboxes-in-nanobox morphology and uniform CoPtX@Co3O4 core–shell nanoparticles with Pt moieties in tunable content and size (from single-atom scale to 2.4 nm). The obtained acid-free CoPtX@Co3O4-NC catalyst achieved an average 92.2% yield of ethyl valerate at a complete conversion of 2-furoic acid, and the reaction ran steadily in a microchannel continuous flow reactor for at least 200 h, which also inhibited the byproduct generation and coke deposition. A mechanistic study suggested that 2-furoic acid was preferably adsorbed on the oxyphilic Co3O4 shell for esterification initially; then the generated esters underwent sequential and exclusive hydrogenolysis steps over the CoPt core to yield valerate esters. The high industrial application prospect of this reaction pathway was additionally highlighted by producing 12 kinds of valeric biofuels from 2-furoic acid and the corresponding C1 ∼ C7 primary, secondary, and tertiary alcohols.
研究领域:
化学工程
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催化材料科学
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产品关联
DOI
高影响因子
MATERIALS SCIENCE FORUM
·
2017
·
IF 0
Heng Xue Xiang,Zi Ye Chen,Wei Chen,Zhe Zhou,Bin Sun,Mei Fang Zhu
As a potential material for food packaging, fully biodegradable composite films based on novel functionalized natural polyphenol/Poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) were successfully fabricated by solution casting, and also the functionalized natural polyphenol (C18TAx) was synthesized by grafting fatty acid onto natural polyphenol Tannic Acid (TA). The resultant C18TAx with better hydrophobicity was uniformly dispersed into a PHBV matrix. The influence of C18TAx dosage on the mechanical behavior, crystallization behavior and thermal properties of the C18TAx/PHBV composite films was investigated by uniaxial tensile mechanical testing, Differential Scanning Calorimeter (DSC), Polarizing Optical Microscope (POM) and Wide Angle X-ray Diffractometry (WAXD). The results revealed that the x value was about 0.09, showing that about 11/20 phenol hydroxy groups in TA molecules were replaced with fatty acid chains. Compared with those of neat PHBV, the tensile strength and elongation at break of the C18TA0.09/PHBV composite films with 10 wt.% C18TA0.09 content were enhanced by 121%, and 458%, respectively. This improvement was primarily ascribed to intermolecular hydrogen bonding interactions in composite films. This new type of fully biodegradable bio-based composite films shows great potential for food packaging.
研究领域:
材料科学
·
食品科学
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产品关联
DOI
FIBERS AND POLYMERS
·
2016
·Vol. 16
·期 12
·2586-2592
·
IF 1.022
Zhao Xiaoyan,Liu Yuan,Wang Chenyi,Liu Qingsheng
A fibrous composite membrane consisting of a chitosan (CS) barrier layer and a poly(hydroxybutyrate-cohydroxyvalerate) (PHBV) fibrous substrate was manufactured as a filter for water purification. The PHBV fibrous supporting layer was fabricated via electrospinning technique, and then the CS solution cast on the PHBV fibers to form the top barrier layer. The structural morphology, mechanical property and adsorption capability of the PHBV/CS membranes were thoroughly investigated. Three heavy metal ions were used to evaluate the equilibrium absorption capacities of the chosen membranes. The equilibrium absorption capacities for Cu(II), Pb(II) and Cd(II) were 64.08 mg/g, 90.32 mg/g and 148.96 mg/ g, respectively. Meanwhile, the rejection ratio of PHBV/CS composite membrane for two disperse dyes could reach to 99 %. The results indicated that PHBV fibrous substrate could not only enhance the mechanical strength of the top barrier layer, but also improve the water permeation of the membrane. This study extended the application of an environmentally friendly material in the water purification without causing much trouble about scrap film.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Water Process Engineering
·
2024
·
IF 6.3
Zhongshuo Xu,Yanfan Jiang,Wei Huang,Yuhui Wang,Xinshan Song
Sulfamethoxazole (SMX) is prevalent as one of the most frequently detected antibiotics in rivers worldwide, and is listed as one of the priority antibiotics in China based on the persistence, bioaccumulation, toxicity and resistance. Recently, the effect of SMX on aerobic granular sludge has attracted increasing interest. However, how SMX influences the biodegradable polymer supported denitrifying granular sludge is still obscure. Herein, two groups with or without exposure to 1 mg/L SMX with initial nitrate concentrations of 15, 30, and 50 mg/L were constructed. Results showed that there was a negligible difference on nitrate removal efficiencies between two groups under stable period (all exceeded 95 %) in batch bioreactors with an HRT of 24 h, supported by an insignificance difference ( p > 0.05). However, the decline in the first-order decay kinetic constants of nitrate removal rate, NAR and NIR activities verified a slight inhibition of SMX on denitrification. Meanwhile, SMX also had an impact on the chemical and microbial properties on granular sludge. SMX boosted the EPS secretion with more humic acid, a delicate rise in PN/PS ratios and a decrease in zeta potential of EPS all favored the microbes' survival under SMX stress. SMX shifted the microbial compositions, namely, the microbes directly involving in PHBV degradation ( Caldimonas , denitrificans Comamonas / Diaphorobacter ) were enriched instead of some denitrifying microorganism that could not directly utilize PHBV ( Denitratisoma , Azospira ). Additionally, even though sul1 and sul2 were enriched, which was not readily accessible to receiving waters due to a good settling properties of granular sludge. This work contributes to a deeper understanding of the impact of SMX on this system, and is of great significance for the operation of granular sludge system for nitrate removal under antibiotic's stress.
研究领域:
环境科学
·
微生物学
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产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2011
·
IF 3.463
Jing Wang,Zongbao Wang,Jun Li,Bingjie Wang,Ji Liu,Peng Chen,Menghe Miao,Qun Gu
Chemically modified chitin nanocrystals were synthesized by grafting poly(3-hydroxybutyrate- co -3-hydroxyvalerate) (PHBV) onto chitin backbone via chlorination. Acetyl amino group was maintained in the reaction. The chemical structure and morphology of PHBV grafted chitin nanocrystals were characterized by Fourier transform infrared, Transmission electron microscopy and X-ray photoelectron spectroscopy. Contact angle measurement showed that the lipophilicity of chitin was improved by the surface modification. The effects of original chitin and PHBV-graft-chitin nanocrystals on the crystallizing and melting behavior of PHBV were studied by differential scanning calorimeter (DSC). The results indicated that both unmodified and modified chitin nanocrystals suppressed crystallization of PHBV. The melt point of PHBV was increased after being mixed with nanofillers.
研究领域:
材料科学
·
生物化学
✓ 已验证
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2017
·
IF 4.811
Du Jun,Zhao Guomin,Pan Mingzhu,Zhuang Leilei,Li Dagang,Zhang Rui
Nanocellulose reinforced poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) composites were prepared using melt compounding. The effects of nanocellulose types (CNCs and CNFs) and nanocellulose content (1, 2, 3, 4, 5, 6 and 7 wt%) on the crystallization, thermal and mechanical properties of PHBV composites were systematically compared in this study. The thermal stability of PHBV composites was improved by both CNCs and CNFs. CNFs with a higher thermal stability leaded to a higher thermal stability of PHBV composites. Both CNCs and CNFs induced a reduction in the crystalline size of PHBV spherulites. Furthermore, CNCs could act as a better nucleating agent for PHBV than did CNFs. CNCs and CNFs showed reinforcing effects in PHBV composites. At the equivalent content of nanocellulose, CNCs led to a higher tensile modulus of PHBV composites than did CNFs. 1 wt% CNCs/PHBV composites exhibited the most optimum mechanical properties.
研究领域:
材料科学
·
高分子科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）