INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2014
·Vol. 39
·期 28
·16123-16131
·
IF 2.93
Yufei Wang,Shuanjin Wang,Min Xiao,Shuqin Song,Dongmei Han,Michael A. Hickner,Yuezhong Meng
Novel sulfonated poly (fluorenyl ether ketone) with pendant quaternary ammonium groups (SPFEKA) was successfully synthesized by one-pot copolymerization of bis(4-fluoro-3-sulfophenyl)sulfone disodium salt, 4,4′-difluorobenzophenone, bisphenol fluorene and 2,2′-dimethylaminemethylene-9,9′-bis(4-hydroxyphenyl) fluorene (DABPF). The chemical structures were confirmed by FT-IR, and 1 H NMR. The thermal properties were fully investigated by TGA . The synthesized copolymers SPFEKAs are soluble in aprotic solvents, and can be cast into membranes on a glass plate from their N,N′-dimethylacetamide (DMAc) solution. A new kind of amphoteric ion exchange membrane (AIEM) was obtained by immersed SPFEKA into 1 M sulfuric acid. The proton conductivities of these membranes are comparable to the most reported sulfonated polymers under the same conditions. The permeability of vanadium ions in vanadium redox flow battery (VRB) was effectively suppressed by introducing quaternary ammonium groups for Donnan exclusion effect . AIEM-20% possess a only 4.4% vanadium ion permeability of Nafion 115. Cell performance tests showed that the VRB assembled with AIEM-20% shows the highest coulombic efficiency (CE) at the current density of 50 mA/cm 2 , because of its lowest VO 2+ permeability. In conclusion, these ionomers could be promising candidates for ion-exchange membranes for VRB applications.
研究领域:
材料科学
·
电化学
·
能源存储
·
高分子化学
·
膜科学
✓ 已验证
DOI
高影响因子
RUSSIAN JOURNAL OF GENERAL CHEMISTRY
·
2021
·Vol. 91
·期 4
·726-731
·
IF 0.868
Xu Y.,Hu Y.,Bao Q.,Zhang J.,Liu B.,Zhang Z.,Zhang Q.,Zhang H.
Copper phyllosilicate has been synthesized from a solution of sodium silicate and copper nitrate by co-precipitation under acidic conditions followed by reduction under H 2 flow for using it as the Cu/SiO 2 catalyst. The catalyst has been characterized by XRD, XPS, FTIR and Raman spectra, EDS, BET, and TEM. It is confirmed that only copper phyllosilicate and SiO 2 exist in the catalyst precursor, and there has been no CuO. Physical and chemical properties of Cu/SiO 2 catalyst have been evaluated. The Cu/SiO 2 catalyst has not only a large specific surface area and abundant mesopores but also the advantages of high dispersion of copper nanoparticles and the combination of Cu 0 and Cu + . The catalyst demonstrates high activity and selectivity in the reaction of 2-butanol dehydrogenation to methyl ethyl ketone.
研究领域:
催化化学
·
材料科学
·
物理化学
·
纳米材料
·
有机合成
✓ 已验证
DOI
高影响因子
COMPOSITES PART B-ENGINEERING
·
2019
·
IF 6.864
Chao Liu,Yufei Dong,Yang Lin,Hongxia Yan,Wenbo Zhang,Yan Bao,Jianzhong Ma
In order to simultaneously improve the dispersibility of graphene in the bismaleimide (BMI) resin and the interfacial interaction between them, the polytriazine@RGO nanocomposite (PTZ@RGO) with terminal amine was obtained by the method of one-step precipitation polymerization. The PTZ@RGO hybrid nanocomposite was then chosen as filler to improve the mechanical and tribological properties of BMI resin. Through effective surface modification, the compatibility and interface strength between graphene and BMI matrix were significantly improved, leading to the flexural strength , impact strength , anti-friction, wear resistance and thermal stability of PTZ@RGO/BMI composites were significantly improved as compared to those of neat BMI resin and RGO/BMI composites. The other properties including hardness and thermal properties of composites were all improved with increasing amount of PTZ@RGO fillers. These high performance BMI composites have a great potential for application in aerospace, mechanical engineering and other automobile brake devices.
研究领域:
材料科学
·
高分子复合材料
·
表面工程
·
摩擦学
·
航空航天材料
✓ 已验证
DOI
高影响因子
IONICS
·
2016
·Vol. 22
·期 11
·2225-2233
·
IF 2.119
Lu Juanjuan,Liu Yuelin,Liu Xinhe,Lu Xiaoquan,Liu Xiuhui
In this article, we constructed an electrochemical sensor for highly sensitive determination of β-nicotinamide adenine dinucleotide (NADH) using the poly(diallyldimethylammonium chloride)-functionalized reduced graphene oxide nanocomposite modified electrode (PDDA-rGO/GCE). The nanocomposite was characterized by transmission electron microscopy, Fourier transform-infrared spectrometry, ultraviolet-visible absorption spectrometry, cyclic voltammetry, and electrochemical impedance spectroscopy. The experimental results demonstrated that the fabricated sensor exhibited excellent electrocatalytic activity on the oxidation of NADH with a decreased about 200 mV in overpotential and 5.0-fold increment in the oxidation peak current compared to a bare GCE. Applying cyclic voltammetry, a wide linear range from 1.0 × 10 −7 to 2.9 × 10 −3 M with low limit of detection (LOD) of 3.4 × 10 −8 M and high sensitivity of 463.3 μA mM −1 cm −2 were obtained, which was superior to other NADH electrochemical sensors reported previously. Furthermore, the fabricated NADH sensor possessed excellent selectivity, reproducibility, and stability. The oxidation mechanism of NADH at the PDDA-rGO/GCE was also discussed in detail.
A simple NADH sensing platform based on PDDA-rGO composite is constructed, which exhibits an ultra-low detection limit ( 3.4×10-8 M) towards the oxidation of NADH, and the electrochemical reaction mechanism of NADH is discussed in detail.
研究领域:
生物电化学
·
生物传感器
·
纳米生物技术
·
分子诊断
·
转化医学
·
电分析化学
✓ 已验证
DOI
高影响因子
Carbon Neutralization
·
2023
·Vol. 2
·期 6
·738-745
·
IF 0
Dabei Wu,Joseph Nzabahimana,Xianluo Hu
The development of organic lithium batteries (OLBs) offers a promising opportunity for the advancement of green and sustainable energy storage systems. However, organic cathode materials face challenges in terms of conductivity, electrochemical activity, and dissolution. Here, we address these limitations by introducing a sulfur-linked carbonyl compound called poly(dichlorobenzoquinone sulfide) (PDBS), which is polymerized in situ on reduced graphene oxide by a mixed solvent thermal method. The resulting carbonyl compound electrode materials exhibit favorable properties as organic cathode materials for OLBs. After 4000 cycles at a current density of 1000 mA g −1 , the carbonyl compound electrodes exhibit a discharge capacity of 102 mAh g −1 . This remarkable performance indicates excellent stability and long cycle life, which are crucial for practical applications. These results suggest that PDBS, a designable sulfur-linked carbonyl compound, holds great promise as an effective organic cathode material for OLBs. In addition, this work provides valuable insights into improving the electrochemical performance of organic cathode materials.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米复合材料
·
有机电极材料
✓ 已验证
DOI
Journal of Nanomaterials
·
2018
·Vol. 2018
·期 1
·1465760
·
IF 2.207
Jiamao Li,Jingwei Hou,Yu Gong,Chengjian Xiao,Lei Yue,Linjie Zhao,Huan Ma,Heyi Wang,Shuming Peng,Chao Chen,Hongli Chen
A liquid-phase reducing method of synthesizing Pt nanocrystals was demonstrated, and dendrite-, cube-, and cuboctahedron-shaped Pt nanocrystals (NCs) with well-defined monomorphic were successfully synthesized through iodine ions mediated with the CTAB agent. When the KI concentration was increased to thirty times of K 2 PtCl 4 at the nucleation stage, the high-quality Pt nanodendrites could be obtained. However, no matter how many KI were added at the growth age, only cube- and cuboctahedron-shaped Pt nanocrystals formed. The results of high-resolution TEM, EDX, and XRD indicated that the size and shape of Pt NCs could be turned by changing the concentration and time of KI. In the nucleation stage, it might be due to that some iodine ions adsorb on the surfaces of Pt NCs, which probably cause the rapid growth process resulting in the formation of Pt nanodendrites. In the growth stage, although high concentrations of I − ions could contribute to the shape control and generate bigger particles of Pt NCs, small Pt particles do not grow into dendrites. The insight into the role of I − ions in synthesis of Pt NCs reported here provided a viewpoint for clearly understanding the formation mechanism of anisotropic platinum nanostructures.
研究领域:
纳米材料科学
·
物理化学
·
无机合成
·
催化化学
·
材料表征技术
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Xin Guan,Huijie Pei,Xiaoyu Chen,Chen Chang,Siyuan Shao,Yu-Mo Zhang,Xingping Zhou,Hui Nie,Xiaolin Xie
The adsorption-catalysis synergy for accelerated conversion of polysulfides is critical toward the electrochemical stability of lithium-sulfur battery (LSB). Herein, a non-metallic polymer network with anion receptor units, trifluoromethanesulfonyl (CF 3 SO 2 -) substituted aza-ether, was in-situ integrated on PE separator, working as an efficient host for anchoring lithium thiophosphates (LPS) as redox mediators and polysulfides through Lewis acid-base interaction. The anchored LPS on the modified PE separator displayed a robust chemical adsorption ability towards polysulfides through the formation of S S bond. Meanwhile, LPS decreased the energy barrier of Li 2 S nucleation and promoted redox reaction kinetics. The battery with LPS decorated separator revealed a long cycling lifespan with a per cycle decay of 0.056 % after 600 cycles, and a competitive initial capacity of 889.1 mAh/g when the of sulfur cathode increased to 3 mg cm −2 . This work developed a new design strategy to promote the utilization of lithium phosphorus sulfide compounds in LSB.
研究领域:
电化学
·
能源材料
·
纳米材料
·
界面化学
·
储能技术
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2015
·Vol. 3
·期 43
·21569-21577
·
IF 7.443
Zhaoqiang Li,Longwei Yin
A sandwich-like structure with reduced graphene oxide (RGO) wrapped MOF-derived ZnCo2O4–ZnO–C polyhedrons on nickel foam as an anode for high performance lithium ion batteries (LIBs) is for the first time reported via simply growing MOFs on Ni foam, and wrapping graphene oxide nanosheets on MOFs, and then annealing under a N2 atmosphere. It should be noted that the MOF-derived porous products are composed of carbon-coated spinel ZnCo2O4–ZnO nanoparticle polyhedrons. When tested as anodes for LIBs, the unique RGO/ZnCo2O4–ZnO–C/Ni sandwich-structured LIB anodes exhibit superior coulombic efficiency, excellent cycling stability and rate capability. The in situ formed carbon layers outside the ZnCo2O4–ZnO act as not only a conductive substrate but also a buffer layer for volume changes. The open pores in ZnCo2O4–ZnO–C polyhedrons provide sufficient electrolyte as well as serve as cushion space to further alleviate volume changes. The RGO nanosheets act as a flexible protector to firmly fix polyhedrons on the Ni foam, as well as a conductive substrate to wire up all the polyhedrons. The interconnected carbon layers and two high conductive substrates (RGO and Ni foam) together form an unhindered highway for charge transfer during discharge/charge processes, promising good electrochemical performance.
研究领域:
材料科学
·
电化学
·
纳米材料
·
能源存储
·
功能材料
·
固态化学
·
电极工程
✓ 已验证
DOI
高影响因子
POLYMER
·
2011
·Vol. 52
·期 23
·5312-5319
·
IF 3.829
Dongyang Chen,Shuanjin Wang,Min Xiao,Dongmei Han,Yuezhong Meng
High-molecular-weight bulky-block poly(fluorenyl ether thioether ketone)s were successfully synthesized by a two steps one-pot protocol using N,N′ -dimethy- S -carbamate masked dithiols for vanadium redox flow battery (VRB) application. The followed sulfonation procedure gave birth to novel sulfonated block poly(fluorenyl ether thioether ketone)s (SPFETKs) with controlled ionic exchange capacities (IEC). Membranes with proton conductivities higher than (IEC > 1.66 mequiv. g −1 ) or comparable to (IEC < 1.66 mequiv. g −1 ) that of Nafion117 membrane were achieved. The VO 2+ permeabilities of SPFETKs membranes were much lower than that of Nafion117 membrane. The thermal properties, mechanical properties, oxidative stability , water uptake, proton conductivity, VO 2+ permeability and cell performance were investigated in detail.
研究领域:
高分子化学
·
能源材料
·
电化学
·
膜科学与技术
·
功能高分子
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2019
·
IF 5.162
Bo Lv,Sha Zeng,Wei Yang,Jian Qiao,Chao Zhang,Chengfeng Zhu,Minghai Chen,Jiangtao Di,Qingwen Li
Recently, the development of high-performance bifunctional oxygen catalysts integrated with flexible conductive scaffolds for rechargeable metal-air batteries has attracted considerable interest, driving by fast-growing wearable electronics . Herein, we report a flexible bifunctional oxygen catalyst thin film consisting of Co–N–C bifunctional catalysts embedding in carbon nanotube (CNT) networks. The catalyst is readily prepared by pyrolysis of cobalt-based zeolitic imidazolate frameworks (ZIF-67) that are in-situ synthesized in CNT networks. Such catalyst film demonstrates very high catalytic activities for oxygen reduction (onset potential: 0.91 V, and half-wave potential: 0.87 V vs. RHE) and oxygen evolution (10 mA cm −2 at 1.58 V) reactions, high methanol tolerance property, and long-term stability (97% current retention). Moreover, our integrated catalyst film shows very good structure flexibility and robustness. Based on the obtained film air electrodes, flexible Zn–air batteries demonstrate low charging and discharging overpotentials (0.82 V at 1 mA cm −1 ) and excellent structure stability in the bending tests . These results indicate that presently reported catalyst films are potential air electrodes for flexible metal–air batteries.
研究领域:
材料科学
·
电化学
·
纳米能源
·
先进功能材料
·
可再生能源
✓ 已验证
DOI
高影响因子
INTERNATIONAL DAIRY JOURNAL
·
2019
·
IF 2.735
Haixia Wang,Jitao Yang,Min Yang,Wei Ji
Maillard reaction products (MRPs) were prepared by reacting both Yak and Holstein casein with different ratios of glucose to casein from 0:1 to 2.5:1. The results showed that the content of intermediate products and browning intensity of the Yak casein-glucose system increased with increasing concentrations of glucose, but were lower than for the Holstein system at the same ratio. With glycosylation, the reducing power and the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity of both Yak and Holstein caseins were enhanced. With increased glucose content, the reducing power of Yak MRPs increased at the same concentration. The metal chelating activity of Holstein MRPs decreased or was eliminated in the ratio range of 0.5:1 to 2.0:1 g glucose g −1 casein, while that of Yak MRPs were reduced in general. Improvement of the inhibitory activity for Yak casein was lower than that of Holstein casein after glycosylation by glucose.
研究领域:
食品科学
·
化学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL DE MYCOLOGIE MEDICALE
·
2018
·
IF 1.606
K. Xu,J.L. Wang,M.P. Chu,C. Jia
Objective The aim of this study was to investigate the antibiofilm activity of coumarin against Candida albicans . Methods The efficacy of coumarin against biofilm formation and the mature biofilm of C. albicans was quantified by crystal violet (CV) staining and the 2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-5-[(phenylamino)carbonyl]-2H-tetrazolium hydroxide (XTT) reduction assay. The effect of coumarin on C. albicans adhesion was assessed on polystyrene plates and by using the cell surface hydrophobicity (CSH) assay. The morphological transition of C. albicans was conducted in two types of hyphae-inducing media at 37 °C. The expression of hypha/biofilm-related genes was evaluated using qRT-PCR analysis. A rescue experiment involving addition of exogenous cyclic adenosine monophosphate (cAMP) was performed to investigate the involvement of cAMP in the yeast-to-hyphae transition. A C. albicans -infected Caenorhabditis elegans model was used to test the anti-virulence efficacy of coumarin. Results Treatment with coumarin strongly affected the capacity of C. albicans to form biofilm and significantly impaired the preformed mature biofilm. The addition of coumarin notably inhibited C. albicans adhesion, CSH, and filamentation . The expression of some adhesion- and hypha-related genes, including HWP1 , HYR1 , ECE1 , and ALS3 , was remarkably down-regulated upon exposure to coumarin. Supplementation with cAMP partly rescued the coumarin-induced defects in hyphal development. Finally, coumarin prolonged survival in C. albicans -infected nematodes. Conclusion Coumarin inhibited C. albicans biofilm, which was associated with attenuated adhesion and hyphal growth.
研究领域:
微生物学
·
药理学
·
分子生物学
✓ 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）