Materials Express
·
2023
·Vol. 13
·期 7
·1274-1285
·
IF 0.7
Tian Zenan,Liu Jidong,Liu Yida,Li Wensong,Zhang Ridong,Lv Jianhua
Activation is essential for improving the structure and surface functional groups of carbon-based solid acids (CSA) during the preparation of carbon materials. This paper compared the catalytic activity of CSA treated non-, KOH-, H3PO4-, and ZnCl2-activation
in esterification of ethylene glycol (EG) and acetic acid (HAc) to synthesize ethylene glycol monoacetate (EGMA). The catalysts were characterized using N2 isothermal adsorption–desorption, acid-base titration, Fourier transform infrared (FT-IR) spectroscopy, scanning electron
microscopy (SEM), Raman spectrometer, X-ray photoelectron spectroscopy (XPS), and X-ray diffractometer analysis (XRD). The results showed that activation treatment clearly enhanced the CSA’s specific surface area and significantly influenced the distribution of surface functional groups.
Notably, the CSA activated with H3PO4 had a markedly higher density of –SO3H groups than the non- activated, KOH- activated, and ZnCl2-activated CSA. The high density of –SO3H on the catalyst surface is advantageous for the
synthesis of EGMA from EG and HAc, making the H3PO4-activated CSA the best performer. The reaction conditions were optimized on H3PO4-activated CSA, resulting in a 74.1% conversion of EG and an 81.8% selectivity of EGMA at 100 °C for 30 min,
and the EG/HAc molar ratio of 1:2. H3PO4-activated CSA was not obviously deactivated even after five cycles, and the decrease of its catalytic performance was related to the leaching of –SO3H on the catalyst surface. Overall, these findings suggest that
H3PO4-activated CSA offers the benefits of less cost, a simpler preparation method, and greater catalytic activity compared to other catalysts, making it a desirable option for the synthesis of EGMA.
研究领域:
化学工程
·
催化材料
✓ 已验证
DOI
高影响因子
ENVIRONMENTAL POLLUTION
·
2020
·
IF 6.793
Xulei Zhao,Teng Zhang,Junhe Lu,Lei Zhou,Jean-Marc Chovelon,Yuefei Ji
Sulfate radical (SO 4 − )-based advanced oxidation processes (SR-AOPs) are promising in-situ chemical oxidation technologies widely applied for soil/groundwater remediation. The presence of non-target water constituents may interfere the abatement of contaminants by SR-AOPs as well as result in the formation of unintended byproducts. Herein, we reported the formation of toxic chloronitrophenols during thermally activated persulfate oxidation of 2-chlorophenol (2CP) in the presence of nitrite (NO 2 − ). 2-Chloro-4-nitrophenol (2C4NP) and 2-chloro-6-nitrophenol (2C6NP) were identified as nitrated byproducts of 2CP with total yield up to 90%. The formation of nitrated byproducts is a result of coupling reaction between 2CP phenoxyl radical (ClPhO ) and nitrogen dioxide radical (NO 2 ). As a critical step, the formation of ClPhO was supported by density functional theory (DFT) computation. Both 2C4NP and 2C6NP could convert to 2-chloro-4,6-dinitrophenol (2C46DNP) upon further treatment via a denitration-renitration process. The formation rate of 2C4NP and 2C6NP was closely dependent on the concentration of NO 2 − , solution pH, and natural water constituents. ECOSAR calculation suggests that chloronitrophenols are generally more hydrophobic and ecotoxic than 2CP. Our result therefore reveals the potential risks in the abatement of chlorophenols by SR-AOP, particularly when high level of NO 2 − is present in water matrix.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
Bioengineered
·
2020
·
IF 2.205
Haibo Xiong,Yunpeng Liu,Qingyang Xu
Corynebacterium glutamicum is a safe and popular industrial microorganism that it is gram-positive bacteria with thick cell walls, which hinder the extracellular secretion of products. Surfactant has good surface or interface activity and can destroy the cell membrane of microorganisms. In this study, the surfactant SDS was used to artificially destroy the cell membrane of Corynebacterium glutamicum, increase the permeability of the cell membrane, and increase the ability of the strain to secrete L-isoleucine. This is the first time that surfactants have been applied to the fermentation of Corynebacterium glutamicum. Results indicated that after optimization, the output of L-isoleucine reached 43.67 g/L, which was 13.01% higher than that without sodium dodecyl sulfate. The yield of the by-products, such as valine, leucine, and alanine, was reduced by 72.30%, 64.30%, 71.70%, respectively. This method can promote the production of L-isoleucine while minimizing the damage of SDS to the strain.
研究领域:
生物技术
·
微生物学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2019
·Vol. 166
·期 12
·A2654
·
IF 3.12
Lei Zhang,Dandan Zhu,Hongyu Wang
Solvent dramatically affects the behavior of anion intercalation into graphite electrode in dual-ion batteries (DIBs). Our previous studies have confirmed that the intercalation of ethylene carbonate (EC) solvated PF6− is considerably suppressed. However, in this letter, we show that EC can apparently co-intercalate with PF6− into graphite electrode once ethyl methyl carbonate (EMC) is involved inside. In situ X-ray diffraction (in situ XRD), ex situ XRD, fourier transform infrared (FTIR) spectroscopy and electrochemical impedance spectroscopy (EIS) have been carried out to clarify the underlying reason.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Bioresource Technology Reports
·
2024
·
IF 0
Yi Zhang,Yuqi Zou,Qiuyue Tao,Mingfeng Yang,Marie Harder,Han Wang,Bo Liang,Ioanna Ntaikou,Georgia Antonopoulou,Gerasimos Lyberatos
Polyhydroxyalkanoate (PHA) is a kind of cellular biopolymers, and a renewable alternative to conventional plastics. To promote low-cost PHA production, this study developed a simple and scalable process to recover this polymer from a phenol-fed mixed culture. Cultures containing >50 % PHA were first acidified then treated with NaClO, leading to digestion of cellular materials by HClO. NaClO dosage, HCl/NaClO ratio, and treatment time were tested for their effects on product Purity and Recovery rate. Compared with NaClO alone which obtained 55–74 % Purity and 57–73 % Recovery, acidification improved the extraction efficiency to 62–83 % Purity and 75–97 % Recovery of cellular PHA. Statistical analysis was performed on dosage, ratio and treatment time. The chemical cost of obtaining 1 kg pure PHA ranged $7–10, but can be greatly reduced by applying a denser culture. However, HClO reduced the molecular weight of the PHA products, which needs to be addressed in future studies.
研究领域:
生物高分子材料
·
微生物发酵
·
生物降解塑料
✓ 已验证
DOI
JOURNAL OF POLYMER RESEARCH
·
2023
·Vol. 31
·期 1
·1-11
·
IF 2.8
Guo Zhenyu,Song Weiqiang,Wei Xueqin,Feng Yu,Song Yihong,Cheng Wenxi
Composites of poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) with different mass ratio, containing nano-sized calcium carbonate, benzophenone and triallyl isocyanurate, were prepared by using a double screw extruder, and blown into films by extrusion blow molding. After ultraviolet (UV) exposure at irradiation doses (ID) of 20 J/cm 2 and 40 J/cm 2 , the mechanical, dynamic mechanical and thermal properties of the radiated films were tested and compared with that of the unradiated. The tensile strength of the PLA/PBAT (100/0) film with single PLA phase increased after exposure to UV light, but its fracture energy decreased. In contrast, both the tensile strength and fracture energy of PLA/PBAT (70/30) film with PLA and PBAT co-continuous phases increased after exposure, but both the tensile strength and fracture energy of PLA/PBAT (50/50) film with PBAT continuous phase decreased. The glass transition temperature ( T g ) of PLA/PBAT (100/0) film increased after exposure to UV light, but the T g of both PLA/PBAT (70/30) and (50/50) films unchanged or varied within the error range. The crystallization temperature ( T c ) of all the films did not changed after UV exposure, but the crystallizability significantly decreased. It suggested that UV irradiation was a simple and effective technique to simultaneously improve the strength and toughness of the film with PLA and PBAT co-continuous phases.
研究领域:
材料科学
·
聚合物工程
✓ 已验证
DOI
高影响因子
Journal of Cleaner Production
·
2022
·
IF 11.072
Tongyao Ju,Siyu Han,Yuan Meng,Mengzhu Song,Jianguo Jiang
Coal fly ash (CFA) is a typical industrial solid waste generated from coal combustion . Microwave digestion is a common measure to determine the element compositions for complex samples like CFA, of which the reagents of digestion processes largely affect the results. In this work, to explore the behaviors of major elements during the digestion process and the effects of pre-treatments, the digestion patterns of Al , Ca, Fe, K, Mg and Ti in CFA samples were studied. The results showed that hydrofluoric acid greatly enhanced the digestion when the ratio of HF went up from 0 to 0.22, of which the digestion efficiencies increased from 21.79% to 59.55% for Al, from 82.23% to 88.23% for Ca, from 50.86% to 84.93% for Fe, from 16.94% to 76.95% for K, and from 9.94% to 95.90% for Ti. Perchloric acid functioned the same as nitric acid . The most suitable schemes for major elements in CFA was (7 mL HNO 3 + 2 mL HCl + 2 mL HF) for 0.25 g of samples (Al: 100.00%, Ca: 93.05%, Fe:97.58%, K: 100.00%, Mg: 81.10%, Ti: 98.30%). According to the experiment of pre-treatments and the structure analysis, it could be concluded that Fe mostly existed in the amorphous phase while K and Ti mostly existed in the crystalline phase , and Ca and Mg were mostly embedded in the Al-related crystalline phase.
研究领域:
环境科学
·
化学工程
·
材料科学
✓ 已验证
DOI
高影响因子
Food & Function
·
2021
·Vol. 12
·期 22
·11557-11567
·
IF 5.396
Yimin Zhao,Zouyan He,Wangjun Hao,Hanyue Zhu,Jianhui Liu,Ka Ying Ma,Wen-Sen He,Zhen-Yu Chen
The present study aimed to investigate the effects of protocatechuic acid (PCA) on plasma lipid profiles and associated mechanisms with a focus on reshaping gut microbiota. Twenty-four male hamsters were randomly divided into three groups receiving a high-cholesterol diet (HCD) and two HCD diets containing 0.5% (PL) and 1% (PH) PCA, respectively. Feeding PL and PH diets for six weeks significantly reduced plasma total cholesterol by 18% and 24%, respectively. PL and PH diets also significantly lowered plasma non-HDL cholesterol by 37% and 44%, respectively. This was accompanied by an increase in fecal short-chain fatty acids (SCFAs) and fecal bile acids with up-regulation on gene of cholesterol 7α-hydroxylase and down-regulation of 3-hydroxy-3-methylglutaryl-CoA reductase in the liver. Dietary PCA supplementation decreased hepatic lipid accumulation, whereas it increased fecal excretion of lipids. The 16S rRNA analysis found that dietary PCA significantly reduced the ratio of Firmicutes to Bacteroidetes and increased the relative abundance of Bacteroidales S24-7, whereas it reduced the abundance of Lactobacillaceae. It was concluded that dietary PCA favorably modulated plasma lipid profiles and prevented the accumulation of hepatic cholesterol and lipid disposition. Such effect was mediated at least partially by increasing gut production of SCFAs and fecal excretion of bile acids via modulating the gut microbiome.
研究领域:
营养学
·
微生物学
·
生物化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF CATALYSIS
·
2020
·
IF 7.888
Zifei Yan,Yunpeng Hu,Chencan Du,Jian Deng,Kai Wang,Guangsheng Luo
The acidolysis of epoxides is an important series reaction applied in the polymer industry including coating and rubber. Glycidyl neodecanoate, which is a green material of environmentally friendly coatings, is synthesized through the acidolysis reaction of epichlorohydrin (ECH) with neodecanoic acid. We developed a green catalyst named tetramethylammonium neodecanoate (TMAN) for this reaction. TMAN is totally recyclable and the reaction system can be homogeneous, thus combining the advantages of tertiary amines and quaternary ammonium salts, meanwhile eliminating their drawbacks. Comparing with tetramethylammonium chloride (TMAC) which is a traditional industrial catalyst, the amount of side product dichlorohydrin can be reduced by more than 50%, effective utilization of ECH and yield of the main product can be increased by 5% and 2% respectively, and the reaction time can be reduced by 20% or more. We suggested a main catalytic reaction network including the conversion of TMAN to TMAC at the late stage of the reaction, and TMAC can be easily recycled and reused to prepare TMAN. More importantly, after the replacement of material acid and the carboxylic anion of catalyst, this efficient catalytic system and the mechanism network can be applied to other acidolysis reactions of epoxides.
研究领域:
化学工程
·
绿色化学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2015
·Vol. 133
·期 1
·
IF 1.768
Yue Zhu,Xiang Gao,Yingwu Luo
Poly(methyl methacrylate) (PMMA) block copolymer is interesting because it is compatible with many polymers. A series of poly(methyl methacrylate)- b -poly( n -butyl acrylate) (PMMA- b -PnBA) diblock copolymers with various compositions was synthesized via reversible addition–fragmentation chain-transfer (RAFT) emulsion polymerization with the amphiphilic oligo(methacrylic acid 41 - b -methyl methacrylate 8 ) RAFT agent as both the polymerization mediator and surfactant. The molecular weights of the block copolymers agreed well with the theoretical prediction, although the polydispersity indices were relatively broad. The resulting core [poly( n -butyl acrylate)]–shell (PMMA) particles of PMMA- b -PnBA were found to be very effective impact modifiers for polycarbonate (PC). The diblock copolymer was well dispersed in 100–300-nm particles in the PC matrix, and the dispersed particle size was highly dependent on the block copolymer compositions. PMMA 250 - b -PnBA 550 (the subscripted number signifies the designed degree of polymerization), which was dispersed into 100-nm particles, presented the best capability for improving the impacting properties. Compared with the neat PC, the notched impact strength of PC toughened by 5 wt % PMMA 250 - b -PnBA 550 was increased by four times to 62.81 kJ/m 2 with the same yield strength, a slightly decreased modulus, an increased elongation at break, and an increased tensile strength. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 132 , 42833.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2014
·
IF 4.331
Dan Chen,Xiaolong Ma,Jizhi Zhou,Xi Chen,Guangren Qian
We synthesized a novel magnetic composite, Fe 3 O 4 /Cu(Ni)Cr-LDH, as a heterogeneous catalyst for the degradation of organic dyes in the solution using sulfate radical-based advanced oxidation processes. The physicochemical properties of the composite synthesized via two-step microwave hydrothermal method were characterized by several techniques, such as X-ray diffraction (XRD), inductively coupled plasma (ICP), transmission electron microscopy (TEM) and vibrating sample magnetometer (VSM). The degradation tests were performed at 25 °C with Acid Orange 7 (AO7) initial concentration of 25 mg/L and AO7/peroxymonosulfate (PMS) molar ratio of 1:10, which showed that the complete degradation by Fe 3 O 4 /Cu 1.5 Ni 0.5 Cr-LDH could be achieved and the mineralization rate could reach 46%. PMS was activated by Cu (II) and Fe (II/III) of Fe 3 O 4 /Cu(Ni)Cr-LDH to generate sulfate radicals (SO 4 − ). Subsequently, the organic functional groups of AO7 molecules were destroyed by sulfate radicals (SO 4 − ), inducing the degradation of AO7. Moreover, the catalytic behavior of the catalysts could be reused five times. Therefore, our work suggested that the Fe 3 O 4 /Cu(Ni)Cr-LDH composite could be applied widely for the treatment of organic dyes in wastewater.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CLUSTER SCIENCE
·
2019
·Vol. 30
·期 4
·973-984
·
IF 2.125
Wang Ting,Zhou Qingcheng,Ren Xiaoyu,Zhou Yunshan,Zhang Lijuan,Shehzad Farooq K.,Iqbal Arshad
Single wall carbon nanotube substituted ionic liquids were synthesized successfully by esterification reaction of the carboxylated single wall carbon nanotubes (SWNTs) with hydroxyl ammonium ionic liquids (ILs) of the formula CH 3 N(CH 2 CH 2 OH) 2 (C n H 2n+1 )Br (n = 4, 8, 12), which subsequently reacted with molybdophosphoric acid (PMo 12 ) to form three new ternary composite materials (SWNTs-ILC n -PMo 12 ) (n = 4, 8, 12). The composites modified glass carbon electrodes were used to study electrochemical properties systematically through cyclic voltammetry method. The results showed that electronic conductivity of SWNTs moiety and ionic conductivity of ILs moiety in the composite materials played important roles in the electrochemistry and electrocatalysis. The length of alkyl carbon chain of the ionic liquids in the composite materials was also found to influence the electrochemical properties. The experimental results also showed that all the composites modified electrode can catalytically reduce and detect IO 3 − , BrO 3 − and NO 2 − with very high efficiency (low detection limit, short response time and wide linear range).
研究领域:
材料科学
·
电化学
·
纳米技术
·
分析化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）