ELECTROCHEMISTRY COMMUNICATIONS
·
2019
·
IF 4.197
Qing Zheng,Huibo Shao
The influence of redox species adsorption on the heterogeneous electron transfer (HET) rate of graphene, as well as the methodology for the rational design of intermolecular interactions to optimize the performance of graphene as an electrode modifier, are not completely understood. We investigate the influence of redox species adsorption on the HET rate of a mildly oxidized graphene-modified electrode by chronocoulometry (CC) and cyclic voltammetry (CV) combined with scanning electrochemical microscopy (SECM), using outer-sphere redox species FcCH 2 OH 1+/0 and inner redox species Fe(CN) 6 4−/3– . The results demonstrate that adsorption of outer-sphere redox species on mildly oxidized graphene induces enhancement of HET, which bridges the differences regarding the reactivity of basal and edge plane sites of graphene in the recent literature.
研究领域:
电化学
·
材料科学
·
纳米材料
·
表面化学
✓ 已验证
DOI
高影响因子
SCIENCE AND ENGINEERING OF COMPOSITE MATERIALS
·
2021
·Vol. 28
·期 1
·528-539
·
IF 1.295
Su Xiaofeng,Yu Yitao,Li Bing,Wang Jing,Lu Chuan,Zong Jianping,Li Jinhui,Wang Feng
In order to prepare polyurethane–polysiloxane block copolymers, α,ω-hydroxyalkyl polysiloxanes with methacrylate side chain and α,ω-bis(2-methyl-3-hydroxypropyl)polymethyl(2-methyl-methylpropanoate) siloxanes, were synthesized and characterized in this study. The syntheses process included hydroxyl protection, hydrosilylation, deprotection, and ring-opening equilibrium reactions. The intermediates and target products were characterized by Fourier transform infrared spectroscopy and 1 H nuclear magnetic resonance methods. The characterization results showed that each step was successfully carried out in all the cases. Then the waterborne polyurethane–polysiloxane block copolymers were prepared via step-growth polymerization. The properties of the block copolymer films were characterized by thermal gravimetric analysis, differential scanning calorimetry, and dynamic thermomechanical analysis methods in detail. The experimental results showed that the block introduction of hydroxyalkyl polysiloxane could reduce the water absorption of waterborne polyurethane from 62 to 11%, and significantly improve the water resistance of polyurethane. With the introduction of polysiloxane, the tensile strength decreased and the elongation at break increased. At the same time, with the increase of the polysiloxane content, the glass transition temperature of the soft segment decreased to −56.4°C and the thermal decomposition temperature increased to 300°C. The results revealed that the introduction of polysiloxane could effectively improve the comprehensive performance of polyurethane–polysiloxane block copolymer films.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
SCIENCE AND ENGINEERING OF COMPOSITE MATERIALS
·
2020
·Vol. 27
·期 1
·28-40
·
IF 0.7
Zhang Wenhua,Wu Peipei,Zhang Yunsheng,Zeng Weizhao,Yang Fenghao
The effect of CNTs on the mechanical and damping properties of macro-defect-free (MDF) cements was studied, and polyvinyl alcohol (PVA) fibers were also studied as a contrast. It was found that the compressive strength of MDF cements was not significantly affected by the two types of fibers. The CNTs enhanced the flexural strength of MDF, while PVA fibers made negative contribution. The strengthening mechanism of flexural strength of MDF cements by CNTs can be summarized as fiber bridging, crack deflection and fiber slippage. For the damping properties, the proper contents of CNTs and PVA fibers improved the loss factor significantly. The interface transition zone (ITZ) between the PVA fibers and matrix was large, which was favorable for fiber slippage. The damping property of MDF cements with CNTs was mainly due to the slippage between the inner tubes of the CNTs rather than the slippage between the CNTs and matrix.
研究领域:
土木工程
·
材料科学
✓ 已验证
DOI
高影响因子
SCIENCE AND ENGINEERING OF COMPOSITE MATERIALS
·
2016
·Vol. 24
·期 5
·651-660
·
IF 0.467
Zajna Sherief,Guijun Xian,Sabu Thomas,Anu Ajith
In the present work, functionalized copper nanoparticles (FCuNPs) were grafted onto flax fibers, and the effects on the tensile properties, bonding strength to an epoxy resin, as well as the properties of the flax fiber-epoxy model composites were investigated. The copper nanoparticles were synthesized at ambient temperature by a chemical reduction method. The reduction of solution of copper chloride salt in the polyvinylalcohol medium was done by using sodium borohydrate. Ultraviolet-visible spectroscopy, transmission electron microscopy, and X-ray diffraction studies were used to characterize the size of the synthesized particles. The synthesized copper nanoparticles were applied to saturate the unidirectional flax natural fibers, whose surfaces were previously tailored with the cationic agent triethylammonium chloride. A remarkable improvement in the tensile strength by 75% and modulus by 50% for FCuNPs grafted flax fibers was found. Thermo-mechanical properties of the flax fiber reinforced epoxy composites were studied using DMTA. Finally, the anti-microbial analysis for composites was also conducted against Aspergillus niger spores, and enhanced anti-microbial performance was observed for treated fiber-based composites.
研究领域:
材料科学
·
复合材料工程
·
生物医学
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE AND ENGINEERING OF COMPOSITE MATERIALS
·
2019
·Vol. 26
·期 1
·261-269
·
IF 0.705
Xiazhi Zhou,Wei Zhou,Dianchun Ju,Yinxian Peng,Lei Zhou,Sheng Tang,Jing Wang
In this work, hierarchical porous resins (PRs) are fabricated and applied as novel adsorbent for removal of oily substance. The oil/water (o/w) high internal phase emulsions (HIPEs), stabilized by phenolic resin precursor and tween 80, were used as the template for simultaneous polymerization of aqueous phase, methenamine, sodium persulfate and liquid paraffin. Subsequently, dopamine hydrochloride, 1-dodecanethiol and Fe 3 O 4 particles are grafted onto the interface of PRs via adhesion of dopamine and Markel addition reaction between quinone groups on dopamine and sulfhydryl groups on 1-dodecanethiol. The as-prepared composites possessed hydrophobicity and magnetic property (HPRs). The physical and chemical properties, morphology and adsorption properties of HPRs are characterized by XRD, FT-IR, TGA, SEM, N 2 adsorption-desorption isotherms. The as-synthesized HPRs composites had a typical hierarchical porous structure, and the resulted macropores with a well-defined open-cell and interconnecting pore throat structure could be controlled via the composition of the aqueous phase of emulsion. The hierarchical porous structure of HPRs contained macropores ranging from 0.3 μm to 4 μm and mesopores of 11.26 nm. HPRs have rough and hydrophobic surface (water contact angle of 130 ∘ ) with specific surface area of 15.06 m 2 /g and pore volume of 0.0349 cm 3 /g. The oil adsorption rate and the oil retention rate for toluene are 11.765 g/g and 86.43%, respectively. The oil adsorption rate in the first minute can reach more than 80% of the highest oil adsorption rate. The oil adsorption rate of HPRs after three recycling experiments can still reach 87.32%of the first-time oil adsorption rate.
研究领域:
材料科学
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化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE AND ENGINEERING OF COMPOSITE MATERIALS
·
2016
·Vol. 25
·期 3
·603-610
·
IF 0.467
Chen Guangmei,Wu Lixia,Xu Jiahao,Xu Gewen,Huang Yiping
Polyurethane-acrylate/SiO 2 composite (SPUA) emulsions were synthesized by in situ polymerization accompanying the sol-gel process, in which the hydrolysis reaction and polymerization of monomers could be accomplished at the same time. The particle morphology of the SPUA emulsions was observed by scanning electron microscopy and transmission electron microscopy. The particle diameter was measured on a laser particle size analyzer. The molecular structure of the copolymers was characterized by Fourier transform infrared spectrometer (FTIR). Furthermore, tensile testing machine, Shore durometer, and thermogravimetric analyzer were used to investigate the mechanical properties, hardness, and thermal properties. The results indicated that, by increasing the mass fraction of tetraethyl orthosilicate (TEOS), the mechanical properties of the films were improved remarkably. When the weight % of TEOS was 8% in the SPUA emulsion, the water absorption of obtained film was 2.1%, the tensile strength was 16.8 MPa, the shore hardness was 94, and the temperature for the maximal thermal mass-loss rate was 416°C.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE AND ENGINEERING OF COMPOSITE MATERIALS
·
2021
·Vol. 28
·期 1
·605-612
·
IF 1.295
Hongbo Tang,Jian Zhou,Shengkui Zhong,Yuchang Su,Qunwei Shu,Lihua Xiao
Nano-sized lanthanum hexaboride (LaB 6 )@ titanium dioxide (TiO 2 ) particles with a core–shell structure has been successfully synthesized via a simple sol–gel method. LaB 6 @TiO 2 particles were used as filler in polyvinyl butyral (PVB) matrix and performance of the TiO 2 shell was evaluated. The core–shell nanoparticles were characterized for morphology and structure properties. X-ray diffraction and transmission electron microscope testing results confirm the formation of LaB 6 –TiO 2 core–shell structure. In composite film, LaB 6 improved the thermo-decomposing temperature of PVB matrix from 369.2 to 372.8°C, while the same amount of LaB 6 @TiO 2 further increased the temperature to 381.0°C. In addition, TiO 2 shell redshifted the maximum transmittance of the film from 605 to 669 nm in the visible region. In the near infrared region, its absorption peak shifted from 1,466 to 1,476 nm. This result will be helpful for the development of transparent and thermal insulating materials.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
SCIENCE AND ENGINEERING OF COMPOSITE MATERIALS
·
2021
·Vol. 28
·期 1
·510-515
·
IF 1.295
Shasha Li,Xi Liu,Jianjia Qin,Changqing Fang,Nailiang Liu
To meet the high-precision needs of conductive ink in the field of microelectronic circuit printing, nano silver-coated graphene oxide (GO) composites were prepared as the conductive functional unit of the composites. The results show that compatibility of the GO grafted with ethylene glycol diglycidyl ether is better in the organic matrix than in the inorganic solvents. The nano silver particles attached to the surface of the grafted GO are evenly distributed and uniform in size. Moreover, the conductivity of grafted GO coated with silver particle composites is effectively improved. The composite conductivity is higher than 10 8 S/m, which is close to the electrical conductivity of silver.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CORROSION SCIENCE
·
2024
·
IF 7.4
Xin-Ran Li,Xian-Ze Meng,Qiu-Yu Huang,Jian Wang,Yu-Yua Xiao,Lian-Kui Wu,Fa-He Cao
Metal corrosion exhibits coupled multi-reaction features, making it challenging to quantitatively study the dissolution reaction with variable-valent cations, particularly in valence quantification. This work develops a novel scanning electrochemical microscopy mode and applies it to Ti dissolution study in acidic fluorides. This mode identifies the potential-dependent corrosion reactions and quantifies the valence evolution of Ti from HER to transpassive regions. Results provide direct electrochemical evidence for soluble Ti( z ≤3), for the first time, and revise the reported dissolution equation. The proposed mode overcomes the drawbacks of macro-electrochemical analysis based on coupling information and provides an effective quantitation method for anodic reactions .
研究领域:
材料科学
·
电化学
·
表面科学
✓ 已验证
产品关联
DOI
高影响因子
Sensors & Diagnostics
·
2023
·Vol. 3
·期 1
·135-146
·
IF 0
Ke Gao,Yuying Du,Na Pan,Xuewei Zhou,Liping Lu,Xiayan Wang
Cadmium (Cd) can cause cell oxidative stress and cytotoxicity. Few studies have focused on inhibitory effects on Cd2+-induced oxidative stress and related cytotoxicity. Scanning electrochemical microscopy (SECM) is a highly sensitive and non-invasive electrochemical analytical method. However, no information exists on inhibitory effects on Cd2+-induced cell oxidative stress using SECM technology. Herein, we studied the effects of ascorbic acid (AsA), zinc chloride (ZnCl2), and calcium chelator 1,2-bis (2-aminophenoxy) ethane-N,N,N′,N′-tetraacetic acid tetraethoxy methyl ester (BAPTA-AM) on cell oxidative stress with SECM. Subsequently, we studied the inhibitory effects of AsA, ZnCl2, and BAPTA-AM on Cd2+-induced cell oxidative stress. Consequently, 50 μmol L−1 AsA, 5 μmol L−1 ZnCl2, and 5 μmol L−1 BAPTA-AM did not produce reactive oxygen species (ROS) and had little effect on cell viability. However, they could significantly reduce Cd2+-induced excessive ROS and alleviate apoptosis (P < 0.01). Additionally, AsA had the strongest inhibitory effects on Cd2+-induced oxidative stress, followed by BAPTA-AM and ZnCl2. The inhibitory effects of AsA, ZnCl2, and BAPTA-AM on Cd2+-induced cytotoxicity might result from directly scavenging ROS and inhibiting oxidative stress-mediated signal transduction, enhancing antioxidant activities and maintaining cell membrane stabilities, and chelating excess calcium2+ (Ca2+) to hinder its subsequent signal transduction, respectively. Scavenging excessive ROS and inhibiting cellular oxidative stress-mediated signal transduction might be the most effective way to alleviate Cd2+-induced cytotoxicity. Our study provides empirical evidence on the inhibitory effects of AsA, ZnCl2, and BAPTA-AM as specialized inhibitors against Cd2+-induced cellular oxidative stress and cytotoxicity, providing precious ideas for detoxifying toxic environmental metal pollutants.
研究领域:
生物化学
·
毒理学
·
环境科学
✓ 已验证
DOI
TALANTA
·
2024
·
IF 5.6
Zhigang Yu,Yangkejia Xiang,Xianda Han,Yi Guang,Fengqin Li
A photo/electrochemical coupling interface of Ru[dcbpy] 3 2+ -AMT/Au (AMT; 5-Amino-1,3,4-thiadiazole-2-thiol) was fabricated using a dehydration condensation sulfhydrating method. For the interface functional properties, a combined dual-signal recording (CDSR) method was applied to characterize the response characteristics, and a scanning electrochemical microscopy-electrochemiluminescence (SECM-ECL) imaging was developed to assess the interface distribution uniformity. The interface biosensing compatibility was validated by constructing a simple DNA sensor. The research results show that the interaction between the two functional parameters follows a synergistic effect mechanism in the coupling conditions and an interference effect mechanism in the detection condition. Under optimized conditions, the saturation dual-signal response values are 156.0 and 86.8 μA, respectively. The statistics and imaging comparison analysis validate good interface distribution uniformity and stability performance. The DNA sensor's dual-signal detection limits to the signal probe (SP) are ∼30 fM and 0.3 pM with linear ranges of 100.0 fM ∼ 1.0 nM and 1.0 pM ∼ 10.0 nM, respectively. The fabricated interface exhibits an effective bi-functional response performance compatible with biosensing. The proposed imaging method has a high technical fit for studying photo/electrochemical coupling interfaces and can also provide a reference for other similar coupling interface analyses.
研究领域:
生物传感
·
分析化学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2023
·
IF 8.4
Ming Sui,Yanni Huang,Yang Tang,Jiaoyang Luo,Yiyang Dong,Yifei Guo,Yonggui Ma,Wei Gu,Mengyue Guo,Jingdan Huang,Dandan Kong,Jinping Li,Meihua Yang
Medicinal teas (MT) were popular in Asian countries for its various effective components. However, Pb pollution poses a serious threat to MT consumption due to the irreversible effect on enzyme activity and neurodegenerative disease. Owing to its toxicity and matrix interference, a rapid screening method for Pb at trace level with high sensitivity and accuracy is urgent for MT consumers. Herein, a simple and ultra-sensitive AuNPs/MWCNTs-MB/DNA-GCE quadruplex biosensor was developed and investigated. Specifically, the monitoring technology of scanning electrochemical microscope was utilized to analyze the assembly and application process for screening key parameters in complex matrix , through in-situ characterization of the microstructure changes on stepwise modified sensors. According to the combined results of electrochemical test and Randles-Sevcik equation, the proposed sensor showed a wide linear range from 5.0 * 10 −15 to 5.0 * 10 −13 M with LOD of 0.9 fM. In addition, the optimized sensor exhibited an excellent selectivity under the inference of metals and medicinal components. The proposed biosensor was successfully implemented for the ultrasensitive monitoring Pb pollution in MT while its water infusions recoveries maintained within acceptable range (81–118 %, 82–129 %). In all, AuNPs/MWCNTs-MB/DNA-GCE provided a new insight into the design, optimization, application and mechanism analysis of sensor for reliable sensing in controlling MT pollution and consumption safety.
研究领域:
分析化学
·
环境科学
·
材料科学
·
生物技术
✓ 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）