ChemSusChem
·
2019
·Vol. 12
·期 7
·1368-1373
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IF 7.804
Yanan Jiang,Tao Sun,Xi Xie,Wei Jiang,Jia Li,Bingbing Tian,Chenliang Su
Graphical S‘O’ much win with MXene : A facile method is reported to produce ultrathin Ti 3 C 2 MXene functionalized with oxygen as an electrocatalyst for the hydrogen evolution reaction. The terminal O on the basal plane increases the number of active sites for electrocatalysis. This combined with the high surface area and conductivity enables the O-functionalized MXene to show enhanced electrocatalytic performance for hydrogen evolution. Two-dimensional (2D) transition-metal carbides (MXenes) are widely adopted as potential electrocatalysts for the hydrogen evolution reaction (HER) owing to their metallic conductivity, rich tunable surface chemistry, and atomic thickness with highly exposed active sites. Previously published theoretical results indicate that MXenes functionalized entirely with oxygen have lower Δ G H* for HER. However, MXenes contain many terminal F groups on the basal plane, which is detrimental to the HER. Herein, the development of an ultrathin Ti 3 C 2 MXene nanosheet fully functionalized with oxygen is reported for the HER. The obtained oxygen-functionalized Ti 3 C 2 (Ti 3 C 2 O x ) exhibits a much higher HER activity (190 mV at 10 mA cm −2 ) than that of Ti 3 C 2 T x (T=F, OH, and O). The improved HER performance is attributed to the highly active O sites on the basal plane of Ti 3 C 2 T x MXenes. This study paves way for electrocatalytic applications of MXene materials by tuning their surface functional groups.
研究领域:
材料科学
·
电化学
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产品关联
DOI
PubMed
高影响因子
Applied Sciences-Basel
·
2023
·Vol. 13
·期 4
·2461
·
IF 2.7
Jianliang Jiang,Jingbo Shen,Xiao Yang,Dongqi Zhao,Yakai Feng
To improve the thermal and mechanical properties of epoxy resins, epoxy-functionalized POSS (E-POSS) and glass fiber (GF) were used to reinforce epoxy resin (E51) composites. The tensile, thermo-mechanical, fractured, and thermal tests were carried out to characterize these hybrid materials. The results show that E-POSS and GF could significantly improve the mechanical and thermal properties of epoxy resins due to high crosslink density of resin matrix and synergistic interaction between the epoxy resin, E-POSS, and GF. Compared with the pure E51 resin, the tensile strength of the E51 + E-POSS (10%) + GF (16%) sample increased by 257.6%, and the thermal decomposition temperature (Td5%) of the E51 + E-POSS (10%) + GF (16%) sample increased by 32 °C to 378 °C.Keywords:epoxy resin;epoxy-functionalized POSS;composites;glass fiber
研究领域:
材料科学
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化学工程
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Xuechuan Wang,Jingbo Zhu,Xinhua Liu,Hui Jie Zhang,Xing Zhu
Gelatin (GE), a nontoxic and degradable biomass resource, is a multistage hydrolysate of collagen. However, its application in adhesives was always limited by its brittleness and poor water resistance. In order to overcome this shortcoming, herein, epoxy-terminated hyperbranched polymers (EHPAEs) were first selected as a cross-linking agent to modify the GE extracted from leather solid wastes to prepare a series of novel GE-based environmentally friendly adhesives. First, EHPAE was synthesized and the structure of the hyperbranched polymer was measured by Fourier-transform infrared and 1H NMR spectroscopy. Then, the adhesives were obtained using the EHPAE to modify GE. The adhesion effect of the prepared adhesives was evaluated by tensile and T-peel tests on the surface of leather, in order to determine whether this adhesive achieved the quality requirements for footwear and bags. The result indicated that EHPAE-modified GE-based adhesives had higher solid content, superior adhesion ability, and water resistance. Moreover, the bonding layer of this adhesive was tough and ductile, while the bonding layers of the recently reported GE-based adhesives were brittle. This adhesive also surpassed the recently reported GE-based adhesives in terms of water resistance and adhesion performance.
研究领域:
材料科学
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生物化学
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环境科学
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产品关联
DOI
高影响因子
MACROMOLECULAR RAPID COMMUNICATIONS
·
2025
·
IF 4.3
Chenru Tian,Ganggang Zhang,Jun Liu,Liqun Zhang
The conventional curing methods pose a significant environmental threat due to the use of toxic vulcanizing agents, the release of irritating volatile organic compounds, and the difficulties in recycling end-of-life rubber products. This work demonstrates a catalyst-free, facile, and eco-friendly crosslinking strategy based on the reaction between epoxy-functionalized ethylene-propylene-diene monomer (EEPDM) and dicarboxylic acids. The EEPDM was synthesized via a reusable reaction-controlled phase-transfer catalyst. Then, EEPDM could be effectively crosslinked by dicarboxylic acids without additional additives. The increased acidity of dicarboxylic acids could be conducive to improving the crosslinking rate. Moreover, the curing mechanism and the nature of the crosslinks were investigated, which is crucial for the recyclability of rubbers. The dicarboxylic acid-cured EEPDM exhibited undesirable side reactions, the extent of which showed a positive correlation with the acidity of carboxylic groups. This phenomenon could be primarily attributed to acid-catalyzed self-polymerization via epoxide ring-opening mechanisms, which would be detrimental to the reprocessability. Due to the formation of thermally stable ether linkages, the crosslinked EEPDM exhibited enhanced thermal-oxidative aging behavior. Hence, we envision that this catalyst-free, high-efficiency crosslinking strategy may offer a promising bridge between sustainable modification and high-performance for epoxy-functionalized rubbers, holding potential application in eco-friendly, low-odor automotive sealing strips.
研究领域:
高分子科学
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材料工程
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绿色化学
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橡胶技术
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化学合成
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2021
·
IF 4.759
Qingqing Li,Wenmin Zhang,Yuheng Guo,Hui Chen,Qingqing Ding,Lan Zhang
In this study, an oxygenated carbon nanotubes cages (OCNTCs) material was prepared by calcinating zeolitic imidazole framework-67 (ZIF-67) and then oxidizing the resulting material. The OCNTCs was used as a high efficient solid-phase microextraction (SPME) coating to extract aromatic amines (AAs). The obtained fiber exhibited high selectivity for AAs over other organic compounds in food contact materials (FCMs) due to matched pore size and abundant oxygen-containing groups. Subsequently, coupled with gas chromatography-tandem mass spectrometry (GC-MS/MS), a sensitive method with low limits of detection (0.1-2.0 ng L −1 ), wide linear ranges (0.5-500 ng L −1 ) and good precision (RSDs ≤ 8.6%) was developed for analysis of AAs. The specific migrated AAs from food simulants that prepared by standardized migration and thermal migration test were successfully analysed by this developed method with satisfactory recoveries (81.6% - 118.1%) and precision (RSDs, 2.1-9.5%). The results demonstrated that the prepared OCNTCs-coated fibers displayed excellent extraction performance, suggesting a promising application to investigate the migration behaviors of AAs.
研究领域:
分析化学
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食品安全
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材料科学
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产品关联
DOI
PubMed
高影响因子
ChemistrySelect
·
2023
·Vol. 8
·期 29
·e202300512
·
IF 2.1
Kangjing Wang,Xinyi Dong,Ting Li,Qian Wang,Zhongyang Ding,Weifu Dong
Graphical The contact angle of modified starch was changed from 12.2° to 71.5°, and the particle size was changed from ∼10 μm to ∼300 nm. In the subsequent enzyme catalyzed reaction, the immobilized enzyme is adsorbed at the water oil interface, thereby improving the lipase activity. As a natural macromolecular material, starch is an ideal carrier for enzyme immobilization because of its widely available source, easy regeneration and excellent biodegradability. However, the natural starch cannot be directly used for immobilization due to the large particle size and excessive hydrophilicity. In this paper, the epoxy groups were grafted onto esterified starch by bifunctional reagents. The grafting efficiency of epoxy groups was increased by starvation drop addition. The changes of contact angle and particle size are conducive to the adsorption of immobilized enzyme at the water oil interface in the subsequent enzyme catalytic reaction, hence improve of the lipase activity. The maximum amount of lipase mobilized on such modified starch was ∼143.7 mg/g, which was near 40 mg/g higher than that of those from direct crosslinking. The immobilized enzymes showed excellent resistance to organic solvents and good reusability. Immobilization of lipases on epoxy-functionalized starch nanoparticles can potentially improves the possibility of enzymes industrial application.
研究领域:
生物技术
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材料科学
·
酶工程
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DOI
高影响因子
POLYMER BULLETIN
·
2015
·Vol. 72
·期 11
·2949-2965
·
IF 1.438
Ren Qiang,Xiang Yanli,Huang Chunyan,Li Jian,Wang Chengyi
A novel epoxy resin toughener based on star-shaped copolymer of butyl acrylate (BA) and glycidyl methacrylate (GMA) [poly (BA- co -GMA)] with low viscosity was developed. The star polymers were synthesized by initiators for continuous activator regeneration atom transfer radical polymerization (ICAR ATRP) using tri, tetra and hexa-functional initiators. The branching parameters of star poly (BA- co -GMA) were characterized by gel permeation chromatography with a laser light scattering-viscometry triple detection system. Copolymer composition and glass transition temperatures of the copolymers were analyzed by proton nuclear magnetic resonance ( 1 H-NMR) and differential scanning calorimetry (DSC), respectively. The results showed that the branching ratio decreased as the number of arms increased. The epoxide groups of the GMA units were kept intact during ICAR ATRP. Rheological, mechanical tests and dynamic mechanical analysis revealed that star poly (BA- co -GMA)/diglycidyl ether of bisphenol A (DGEBA) epoxy resin formulation exhibited better processability, higher impact resistance and thermal resistance than those of linear poly (BA- co -GMA)/DGEBA epoxy resin formulation.
研究领域:
高分子科学
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）