JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
·
2014
·
IF 2.745
Teng Zhang,Xiao-Ling Xu,Yi-Ning Jin,Jian Wu,Zhi-Kang Xu
Carbon nanotubes are widely applied in electronics, which offers great potential for enhancing the activity of redox enzyme. In this work, polyimide (PI) was blended with multiwalled carbon nanotubes (MWCNTs) and then electrospun into nanofibers for the immobilization of horseradish peroxidase (HRP), a redox enzyme. SEM and TEM were used to characterize the surface morphology of the PI/MWCNTs nanofibers and to analyze the protruding parts induced by the blending of MWCNT. The results indicate that, compared to the virgin PI nanofibers, the blending of MWCNTs increases the retention activity of immobilized HRP from 2.38% to 12.50%. Circular dichroism and UV–vis molecular absorption spectrometry were used to explore the interactions between HRP and MWCNTs . It seems that MWCNTs increase the enzyme activity by the facilitation of electron transfer among the catalytic intermediates “HRP I”, “HRP II” and MWCNTs.
研究领域:
生物化学
·
纳米生物技术
·
酶工程
·
生物材料
·
分析化学
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2022
·
IF 9.221
Yueying Gao,Weiwei Meng,Ling Wang,Yuehua Li,Lei Dai
Salt melt synthesis is a kind of inorganic material synthesis method developed in modern times, which has certain potential advantages and development prospects. The sensing electrode (SE) material In 2 O 3 was synthesized by the salt melt method. The composition and morphology of the synthesized products under different conditions were studied in detail by combining XRD , SEM and TEM characterization. The results show that the salt melt method can facilely synthesize high-purity In 2 O 3 powder at a lower temperature, and its morphology changes regularly with the change of reaction conditions. The effects of synthesis times and temperatures on the gas-sensing performance of In 2 O 3 were discussed. The sensor based on In 2 O 3 (380 °C − 30 min)-SE exhibited superior gas-sensing performance in the range of NH 3 concentration of 50–500 ppm. The NH 3 response characteristics exhibited little effect at different relative humidity (RH) and oxygen partial pressure conditions. In addition, the sensor exhibited good repeatability and selectivity .
研究领域:
材料科学
·
传感器技术
·
无机合成
·
气体传感
·
功能材料
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2022
·Vol. 52
·期 2
·376-383
·
IF 4.569
Enming Ping,Lingyun Kong,Mengyao Liu,Yunshan Zhou,Lijuan Zhang,Nan Chen
The reaction of porous γ-Al2O3 particles acting as both a sacrificial template and an aluminum source with 1,4-naphthalene diacid (H2NDC) resulted in the formation of γ-AlOOH@Al(OH)(1,4-NDC) composites, in which ZIF-67 was then loaded by the in situ crystallization method, leading to the formation of γ-AlOOH@Al(OH)(1,4-NDC)@ZIF-67 composites. The deliberately designed composite was used to separate H2/D2 at 77 K in a 1 m chromatographic column. The results demonstrated that the optimized composite can achieve the effective separation of H2/D2 in gas chromatography due to the additive effects of kinetic sieving and chemical affinity quantum sieving of Al(OH)(1,4-NDC) and ZIF-67. By optimizing chromatographic separation conditions, the resolution R reached 2.02 with the separation time t = 7.72 min. The composite also showed satisfactory repeatability and reproducibility.
研究领域:
材料科学
·
分离科学
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物理化学
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纳米材料
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能源化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMISTRY
·
2013
·Vol. 31
·期 3
·371-376
·
IF 0.917
Wei Zhu,Haoyang Wang,Haihui Peng,Guosheng Liu,Yinlong Guo
Pd-catalyzed oxidative coupling reaction was of great importance in the aromatic C H activation and the formation of new C O and C C bonds. Sanford has pioneered practical, directed C H activation reactions employing Pd(OAc) 2 as catalyst since 2004. However, until now, the speculated reactive Pd(IV) transient intermediates in these reactions have not been isolated or directly detected from reaction solution. Electrospray ionization tandem mass spectrometry (ESI-MS/MS) was used to intercept and characterize the reactive Pd(IV) transient intermediates in the solutions of Pd(OAc) 2 -catalyzed oxidative coupling reactions. In this study, the Pd(IV) transient intermediates were detected from the solution of Pd(OAc) 2 -catalyzed oxidative coupling reactions by ESI-MS and the MS/MS of the intercepted Pd(IV) transient intermediate in reaction system was the same with the synthesized authentic Pd(IV) complex. Our ESI-MS(/MS) studies confirmed the presence of Pd(IV) reaction transient intermediates. Most interestingly, the MS/MS of Pd(IV) transient intermediates showed the reductive elimination reactivity to Pd(II) complexes with new C O bond formation into product in gas phase, which was consistent with the proposed reactivity of the Pd(IV) transient intermediates in solution.
研究领域:
有机化学
·
金属有机化学
·
分析化学
·
催化化学
·
质谱学
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2017
·Vol. 28
·期 11
·1438-1447
·
IF 1.907
Xin Liu,Xuewen Guo,Yunfei Zhi,Shaoyun Shan,Yonghao Ni,Qingming Jia
The recent development of sulfur dioxide (SO 2 ) polymerization has seen a renaissance in its chemistry, especially poly(olefin sulfone)s from the copolymerization of SO 2 , and unsaturated hydrocarbons can be found to have many applications, including transient electronic packaging, drug delivery, and electron beam-resistant materials. In this work, a type of functional poly(norbornene sulfone) was synthesized via two different polymerization methods. Aiming to understanding the effects of different polymerization methods on poly(olefin sulfone)s and gain further understanding on the kinetics of poly(olefin sulfone)s's thermal instability, we investigated their detailed thermal degradation behaviors using thermogravimetry and analyzed the resultant kinetics in accordance with three kinetic models. The results supported the conclusion that although the poly(norbornene sulfone)s obtained have different activation energy, the thermal degradation kinetics are the same and also obey the D n type. Copyright © 2017 John Wiley & Sons, Ltd.
研究领域:
高分子化学
·
材料科学
·
热分析
·
功能高分子
·
可控降解材料
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2015
·
IF 4.504
Yan Zhang,Ming-Ming Gao,Xin-Hua Wang,Shu-Guang Wang,Rui-Ting Liu
An electro-Fenton process was developed for wastewater treatment in which hydrogen peroxide was generated in situ with a rotating graphite disk electrode as cathode. The maximum H 2 O 2 generation rate for the RDE reached 0.90 mg/L/h/cm 2 under the rotation speed of 400 rpm at pH 3, and −0.8 V vs SCE. The performance of this electro-Fenton reactor was assessed by tetracycline degradation in an aqueous solution. Experimental results showed the rotation of disk cathode resulted in the efficient production of H 2 O 2 without oxygen aeration, and excellent ability for degrading organic pollutants compared to the electro-Fenton system with fixed cathode. Tetracycline of 50 mg/L was degraded completely within 2 h with the addition of ferrous ion (1.0 mM). The chronoamperometry analysis was employed to investigate the oxygen diffusion on the rotating cathode. The results demonstrated that the diffusion coefficients of dissolved oxygen is 19.45 × 10 −5 cm 2 /s, which is greater than that reported in the literature. Further calculation indicated that oxygen is able to diffuse through the film on the rotating cathode within the contact time in each circle. This study proves that enhancement of oxygen diffusion on RDE is benefit for H 2 O 2 generation, thus provides a promising method for organic pollutants degradation by the combination of RDE with electro-Fenton reactor and offers a new insight on the oxygen transform process in this new system.
研究领域:
环境科学
·
电化学
·
水处理技术
·
污染物降解
·
反应工程
✓ 已验证
DOI
高影响因子
TETRAHEDRON
·
2014
·Vol. 70
·期 47
·9033-9040
·
IF 2.817
Tao Liu,Meng-Meng Liu,Xiao-Wen Zheng,Chong-Yang Du,Xiang-Yang Cui,Lu Wang,Ling-Li Han,Zhang-Yu Yu
The redox reactions of p -hydroquinone and pyrocatechol undergo a two-proton-two-electron process in aqueous solution. We calculated their redox potentials at the B3LYP/6-311+G(d,p) level, and verified the values by employing cyclic voltammetry experiments. Then we selected seven substituent groups (–F, –Cl, –OH, –COOH, –CN, –NH 2 , and –NO 2 groups) to systematically investigate the substituent effect , including the sort, position, and number of the substituent, on the redox potentials of p -hydroquinone and pyrocatechol. The calculated results show that –NH 2 and –OH groups can decrease the redox potentials, while –F, –Cl, –COOH, –CN, and –NO 2 groups increase the potential values of p -hydroquinone and pyrocatechol. The calculations can accurately predict the substituent effects on the redox potentials of pyrocatechol and p -hydroquinone. We would expect that the accurate calculation results for the model systems could be applied in the prediction of electrode potentials of other molecules.
研究领域:
物理有机化学
·
电化学
·
计算化学
·
分子设计
·
生物电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Nan Liu,Zhi Dong,Zongqing Ma,Liming Yu,Chong Li,Chenxi Liu,Qianying Guo,Yongchang Liu
The bimodal distribution of tungsten grain size, which is also called bimodal structure, is a universal phenomenon in synthesizing tungsten based nanopowders by wet chemical method , and could significantly deteriorate further sintering characteristics of the powders. In this paper, W-Y 2 O 3 composite nanopowders with small grain size and no bimodal structure were synthesized by an improved wet chemical method. It was found that reaction conditions, especially the hydrogen ion concentration(ρ(H + )) could significantly influence the microstructure and morphology of the prepared composite nanopowders and has an optimum value of approximately 0.16 mol L −1 . W-Y 2 O 3 composite nanopowders synthesized under this optimum value got not only the minimum average grain size, which is about 17 nm, but also the best grain size uniformity with no bimodal structure. The microstructure of co-deposited precursors and prepared powders was analyzed in detail to figure out the specific influence mechanism of ρ(H + ), and it was indicated that ρ(H + ) could influence the microstructure and the Y 2 O 3 content of the reduced powders through affecting the fraction of precursor that has little yttrium content, which may lead to the bimodal distribution of tungsten grain size of the prepared powders. Furthermore, the formation mechanism of bimodal structure was systematically analyzed and a feasible method was proposed to eliminate the bimodal structure. It is suggested that the bimodal distribution of tungsten grain size is attributed to the distribution of Y 2 O 3 during hydrogen reduction process and can be well avoided by controlling ρ(H + ).
研究领域:
材料科学
·
纳米材料
·
粉末冶金
·
无机非金属材料
·
功能材料
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2019
·
IF 3.131
Xiaotong Sun,Luting Yan,Runxiang Xu,Mingyuan Xu,Yanyun Zhu
TiO 2 presents a broad application prospect in the field of degradation of environmental pollutants. However, the development of TiO 2 photocatalyst has been limited by two factors, namely, narrow spectral response range and low quantum efficiency . Surface coating can selectively change the physical and chemical properties of core particles, whereas the synergistic action between core and shell can optimize material performance. In this paper, surface modification of titanium dioxide (TiO 2 ) by dopamine polymerization was used to improve its photocatalytic performance. Among polydopamine (PDA)-modified TiO 2 , TiO 2 @PDA-0.4 mg/mL-2 h showed the best degradation rate of Rhodamine B (RhB): the degradation rate reached 99.28% and 77.40% after 1.5 h of ultraviolet–visible (UV–vis) and visible (Vis) light irradiation, respectively. Compared with the uncoated TiO 2 , the degradation rate has shown improvement, especially under Vis light irradiation, with the photocatalytic performance improving by 35.04%. Absorption, emission, and impedance spectra showed that surface modification of TiO 2 with suitable thickness of PDA effectively increased light absorption and promoted separation of photogenerated carriers . High-performance liquid chromatography–mass spectrometry revealed the differences in photocatalytic degradation mechanism of TiO 2 @PDA to RhB under UV–vis and Vis light irradiation. Compared with those under UV–vis light irradiation, the intermediate products under Vis light irradiation are relatively simple. TiO 2 @PDA generated more electrons, which interacted with H 2 O to produce large amounts of ·OH and holes under UV–vis light irradiation in comparison with that under Vis light irradiation. In addition to deacetylation , deamination , and decarboxylation by hydroxylation , excess ·OH in the photocatalytic process would attack benzene rings directly to produce N , N -diethylacetamide.
研究领域:
材料科学
·
环境化学
·
光催化
·
纳米材料
·
表面工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS CHEMISTRY
·
2011
·Vol. 21
·期 40
·16028-16034
·
IF 5.101
Jun Shi,Zhengzheng Zhang,Gefei Li,Shaokui Cao
Alginate/CaCO3 hybrid beads with pH- and thermal-responsive drug release properties were prepared under compressed CO2 using aliphatic poly(urethane-amine)s (PU) as the thermal-responsive component. Polyacrylic acid (PAA) was used as a crystal growth additive to control the structure of the hybrid beads. The hybrid beads were characterized by using scanning electron microscopy, X-ray powder diffraction and thermogravimetric analysis. The interaction between PAA and aliphatic PU contributed to the formation of alginate beads with a compact CaCO3 shell. Indomethacin release behaviour was found to be pH- and thermal-responsive. The release profiles were sustained with CaCO3 microparticles, indicating that the compact CaCO3 shell could hinder the permeability of the encapsulated drug and reduce the drug release effectively. The results suggest that the hybrid alginate beads can be used as “smart” polysaccharide materials for sustained dual-responsive drug delivery.
研究领域:
生物材料
·
药物递送系统
·
高分子科学
·
纳米医学
·
药剂学
·
生物化学
·
组织工程
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2022
·
IF 7.336
Feihong Zhang,Qiaohang Weng,Yanxiang Zhang,Na Ai,San Ping Jiang,Chengzhi Guan,Yanqun Shao,Huihuang Fang,Yu Luo,Kongfa Chen
Solid oxide fuel cells (SOFCs) are the most efficient energy conversion technology to convert the chemical energy of fuels like hydrogen, natural gas, etc. to electricity. However, one of the limiting factors in the commercial viability of SOFCs technologies is the time-consuming and high-cost multiple cell fabrication processes. Here, we report the development of a facile procedure for the preparation of an electrolyte-supported cell with a Ni-Gd 0.1 Ce 0.9 O 1.95 composite anode and a La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ cathode, and the fabrication procedure of the electrodes decreases from four steps of screen-printing and sintering of conventional cell preparation processes to two steps of screen-printing using a direct assembly approach without the high-temperature sintering steps. The most important observation is the simultaneous formation of the electrode/electrolyte interfaces of both the anode and cathode by in situ passing a current through the directly assembled cells at 800 ℃. The power density of the directly assembled cell reaches 0.41 W cm −2 at a voltage of 0.7 V and 800 ℃, close to 0.46 W cm −2 of the sintered cell. The directly assembled cell shows comparable operational stability to the sintered cell at 800 ℃ for 100 h. This work sheds light on the facile fabrication of electrolyte-supported cells with substantially simplified preparation procedures and reduced costs.
研究领域:
材料科学
·
能源化学
·
电化学
·
燃料电池技术
·
无机功能材料
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Lichun Ma,Nan Li,Guangshun Wu,Guojun Song,Xiaoru Li,Ping Han,Gang Wang,Yudong Huang
A novel amine-based functionalization method was developed to improve the interfacial adhesion between TiO 2 NWs and CFs in supercritical water. The microstructure, morphology and mechanical properties of CFs were investigated. It was found that introducing hexamethylenetetramine (HMTA) dendrimers and branched polyethyleneimine (PEI) on CF could increase significantly the adhesion strength between CF and TiO 2 NWs and their interfacial shear strength with epoxy resin, and the order is CF-PEI-TiO 2 NWs > CF-HMTA-TiO 2 NWs > CF-COOH-TiO 2 NWs > CF-TiO 2 NW. Meanwhile, the reinforcing mechanisms and interfacial failure modes have also been discussed. We believe that these effective methods may provide theoretical foundation for the preparation of high performance composite materials.
研究领域:
材料科学
·
复合材料界面工程
·
纳米材料修饰
·
高分子基复合材料
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）