Materials
·
2016
·Vol. 9
·期 9
·792
·
IF 2.728
Jianfeng Ban,Linjiang Zhu,Shaojun Chen,Yiping Wang
To better understand shape memory materials and self-healing materials, a new series of liquid-crystalline shape memory polyurethane (LC-SMPU) composites, named SMPU-OOBAm, were successfully prepared by incorporating 4-octyldecyloxybenzoic acid (OOBA) into the PEG-based SMPU. The effect of OOBA on the structure, morphology, and properties of the material has been carefully investigated. The results demonstrate that SMPU-OOBAm has liquid crystalline properties, triple-shape memory properties, and self-healing properties. The incorporated OOBA promotes the crystallizability of both soft and hard segments of SMPU, and the crystallization rate of the hard segment of SMPU decreases when the OOBA-content increases. Additionally, the SMPU-OOBAm forms a two-phase separated structure (SMPU phase and OOBA phase), and it shows two-step modulus changes upon heating. Therefore, the SMPU-OOBAm exhibits triple-shape memory behavior, and the shape recovery ratio decreases with an increase in the OOBA content. Finally, SMPU-OOBAm exhibits self-healing properties. The new mechanism can be ascribed to the heating-induced “bleeding” of OOBA in the liquid crystalline state and the subsequent re-crystallization upon cooling. This successful combination of liquid crystalline properties, triple-shape memory properties, and self-healing properties make the SMPU-OOBAm composites ideal for many promising applications in smart optical devices, smart electronic devices, and smart sensors.
研究领域:
高分子材料学
·
智能材料
·
功能高分子
·
自修复材料
·
形状记忆材料
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2018
·
IF 4.229
Dandan Li,Congcong Wei,Qiang Wang,Lin Liu,Dazhong Zhong,Genyan Hao,Jinping Li,Qiang Zhao
Silver-based catalysts with an adjustable structure are promising as efficient oxygen evolution catalysts. Four types of silver-oxide (AgO) morphologies were obtained by potentiostatic deposition in situ in organic carboxylate by altering the amount of ammonia as the complexing agent. AgO films can be used in the oxygen-evolution reaction; AgO that is formed by using potassium acetate that contains 1.32 mM ammonia as an electrolyte exhibits preferable performance. Catalyzed water oxidation occurs in 0.1 mol/L potassium phosphate solution (pH 12.3) with an average activity of 3.5 mA/cm 2 , and persists for at least 10 h at 2.03 V (vs. Reversible Hydrogen Electrode, RHE). Overpotential is 438 mV at a current density of 1 mA/cm 2 . The Faradaic efficiency is 94.4%. Samples were well characterized by X-ray powder diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy.
研究领域:
材料化学
·
电化学
·
催化化学
·
能源科学
·
纳米材料
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可持续能源
·
表面科学
✓ 已验证
DOI
高影响因子
Soft Matter
·
2018
·Vol. 14
·期 21
·4355-4363
·
IF 3.709
Lei Wu,Guoyong Mao,Guodong Nian,Yuhai Xiang,Jin Qian,Shaoxing Qu
Load-bearing applications of hydrogels call for materials with excellent mechanical properties. Despite the considerable progress in developing tough hydrogels, there is still a requirement to prepare high-performance hydrogels using simple strategies. In this paper, a sponge-reinforced hydrogel composite is synthesized by combining poly(acrylamide) (PAAm) hydrogel and polyurethane (PU) sponge. Uniaxial compressive testing of the hydrogel composites reveals that both the compressive modulus and the strength of the hydrogel composites are much higher than those of the PAAm hydrogel or sponge. In order to predict the compressive modulus of the hydrogel composite, we develop a theoretical model that is validated by experiments and numerical simulations. The present work may guide the design and manufacture of hydrogel-based composite materials, especially for biomaterial scaffolds and soft transducers.
研究领域:
生物材料学
·
组织工程
·
生物力学
·
高分子材料
·
再生医学
✓ 已验证
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2019
·Vol. 127
·期 2
·715-726
·
IF 1.428
Zhang Wei-Hong,Zhou Yu-Chen,Du Chen-Hui,Gao Min,Liu Shan-Shan,Liu Ping,Li Yong-Xin
A basic ionic liquid containing aminopropylimidazolium moiety and OH ‒ anion was immobilized on silane-functionalized graphene oxide (GO) by a condensation process, followed by an anion-exchange reaction. The properties of the resulting GO-[Ap-im]OH material were characterized using extensive techniques including FTIR, XPS, AFM, TGA, etc. The material could be used as a transesterification catalyst, affording the expected ester products in good yields under mild reaction conditions. This GO-[Ap-im]OH material with amino groups shows higher activity than GO-[Ap-im]Cl without amino groups. Furthermore, this catalyst could easily be separated from the reaction mixture by filtration and recycled at least 6 times without a noticeable decrease in the catalytic activity. The prominent performance of GO-[Ap-im]OH is attributed to the enhanced basicity of combining amine groups and OH ‒ anions as well as less mass-transfer resistance of laminar GO.
研究领域:
催化化学
·
材料化学
·
有机合成
·
绿色化学
·
纳米材料
✓ 已验证
DOI
高影响因子
MICROCHIMICA ACTA
·
2016
·Vol. 183
·期 5
·1543-1551
·
IF 4.831
Liu Ren,Zeng Xuebiao,Liu Jingcheng,Luo Jing,Zheng Yuanyi,Liu Xiaoya
The article describes an electrochemical sensor for simultaneous determination of dopamine (DA) and paracetamol (PAT). It is based on the use of an electroactive polymer (referred to as BPVCM) to functionalize multi-walled carbon nanotubes. BPVCM is a branched amphiphilic photo-sensitive and electroactive polymer that was obtained by copolymerization of a vinyl benzylcarbazole, maleic acid anhydride, 4-vinylbenzylthiol and a vinylbenzyloxycoumarin. BPVCM efficiently disperses MWCNT in aqueous solution. The electropolymerization of the carbazole moieties of the BPVCM enhances the current response. It also facilitates electron transfer in the MWCNT-BPVCM hybrid as evidenced by cyclic voltammetry and electrochemical impedance spectroscopy. A glassy carbon electrode modified with the nanocomposite displays outstanding electrocatalytic activity towards DA and PAT. DA can be determined, best at a working voltage of 0.2 V (vs. SCE), in the 5 to 1000 μM concentration range with a 2.3 μM detection limit. PAT can be determined in parallel, at a working voltage of 0.39 V (vs. SCE), in the same concentration range with a 3.5 μM detection limit. This analytical range of this method is wider than that of most alternative methods.
An electrochemical sensor for simultaneous determination of dopamine (DA) and paracetamol (PAT) is described. It is based on the use of an electroactive polymer (referred to as BPVCM) to functionalize multi-walled carbon nanotubes. The electropolymerization of BPVCM enhances the current response and improves the analytical range of the sensor.
研究领域:
分析化学
·
生物医学工程
·
药物分析
·
纳米材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Systems Microbiology and Biomanufacturing
·
2022
·Vol. 3
·期 2
·262-272
·
IF 0
Niu Chengtuo,Xing Xianlei,Zheng Feiyun,Liu Chunfeng,Wang Jinjing,Li Qi
This study aimed to reveal the effect of salt reduction on the nutritional, functional and sensory aspects of doubanjiang through preparing three sets of doubanjiang fermentation (Sample H, Sample M and Sample L) with different salt concentrations. The results showed that fermentation with lower salt concentration led to significantly higher amino acids concentrations in doubanjiang, while the organic acids concentrations were also slightly increased. For biologically active compounds, the concentrations of total flavonoids, total phenols and five monomer isoflavones in Sample L were all significantly higher than those in Sample M and Sample H. Moreover, better anti-oxidant ability was observed in doubanjiang samples fermented with lower salt concentration. Bacillus and Millerozyma genus were found to be closely related to the formation of amino acids and biologically active compounds in doubanjiang, while organic acids were highly correlated with Cronobacter , Erwinia , Trabulsiella , Enterobacter and Millerozyma genus. Through sensory evaluation and electric tongue, unsatisfactory sensory characteristics, such as lighter color, strong acid taste and off-flavor, were found in lower salt fermented doubanjiang samples. This indicated that lower salt concentration favored the nutrition and function of doubanjiang while negatively influenced doubanjiang flavor. This study deepened our understanding of the roles of salt concentration on doubanjiang fermentation and provided guidance for the further development of low-salt doubanjiang .
研究领域:
食品科学
·
微生物学
·
生物化学
·
感官分析
✓ 已验证
DOI
JOURNAL OF APPLIED POLYMER SCIENCE
·
2012
·Vol. 129
·期 2
·846-852
·
IF 1.289
Hong Yu Yang,Xiu Mei Zhang,Li Jie Duan,Ming Yao Zhang,Guang Hui Gao,Hui Xuan Zhang
A series of environmental pH-responsive block copolymers PEG-polyurethane with tertiary amine groups in the main chain and free carboxyl groups in the side chain were synthesized, including poly(ethylene glycol) (PEG), 1,4-bis (hydroxyethyl) piperazine, 1,6-diisocyanato hexamethylene, and 2,2-dimethylolpropionic acid. The chemical structure, molecular weight, and pH-dependent capacity of pH-responsive PEG-polyurethane were examined by 1 H-NMR, FTIR, gel permeation chromatography (GPC), and an acid-base titration. Moreover, the fluorescent dye fluorescein isothiocyanate was conjugated with PEG-polyurethane by the similar polymerization method and the obtained polymer was measured by ultraviolet visible spectroscopy (UV-vis) and fluorescent spectroscopy. The results indicated that the pH-responsive PEG-polyurethane showed a pH-buffering phenomenon and fluorescent imaging in a range of pH values. As a result, we demonstrated its potential application for optical imaging; however, it is believed that more applications in the areas of biomedicine will be possible owing to its free carboxyl acid terminal residues in the stimuli-responsive polymer. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
研究领域:
生物材料
·
分子影像学
·
高分子化学
·
纳米医学
·
药物递送
·
生物传感器
·
转化医学
✓ 已验证
DOI
高影响因子
Advanced Optical Materials
·
2022
·Vol. 10
·期 13
·2200276
·
IF 10.05
Chenwei Liu,Yongjie Liu,Shuxin Wang,Jiwei Liang,Cheng Wang,Fang Yao,Weijun Ke,Qianqian Lin,Ti Wang,Chen Tao,Guojia Fang
Quasi-two-dimensional (quasi-2D) perovskite light-emitting diodes (PeLEDs) are considered as one of the most potential candidates in electroluminescence territory owing to their unique quantum confinement effect and excellent thermal stability of the light. Nevertheless, heterogeneous energy domain distribution leads to severe non-radiative recombination in the process of energy transfer, which enormously hinders the performance and application of PeLEDs. Herein, an ambipolar amino acid, 5-aminovaleric acid (5AVA), is demonstrated to be able to coordinate lead and halides simultaneously with its carboxyl and amidogen groups. The coordinated ambipolar molecule not only reconstitutes energy domains of perovskites but also minimizes the interfacial defects of PeLEDs. Accordingly, the presence of 5AVA in perovskite precursors leads to dramatic suppression of the n = 1 and n = 2 phases and accelerates energy transfer from wide bandgap domains to narrow bandgap ones. As a result, maximum external quantum efficiency (EQE) of 19.3% (18.20% ± 1.10%) is achieved in quasi-2D green PeLEDs with current efficiency of 61.7 cd A −1 .
研究领域:
材料科学
·
光电子学
·
纳米科技
·
半导体器件
·
凝聚态物理
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2017
·Vol. 135
·期 11
·45974
·
IF 1.86
Wenqi Xian,Lina Song,Baohua Liu,Hulan Ding,Zhao Li,Mengping Cheng,Le Ma
CO 2 copolymer diol-based thermal polyurethane elastomers (PPC-TPU) were prepared by the reaction of CO 2 copolymer diol and methylene diphenyl diisocyanate and chain extender (ethylene glycol/1,4-butanediol/1,6-hexanediol) (EG/BDO/HG). The rheological and mechanical properties of PPC-TPU were analyzed. The effects of shear rate, shear temperature, hard segment content, and variety of chain extender on the properties of PPC-TPU were studied. The results showed that the apparent viscosity (η) of PPC-TPU decreased with the increasing shear rate ( τ ), and the non-Newtonian index ( n ) was less than 1. PPC-TPU exhibited a typical character of pseudoplastic non-Newtonian rheological behavior. The degradation during the processing was obviously inhibited by adding plasticizer and antioxidant. It was also discovered that the apparent viscosity varied with the content of hard segment and chain extender. Under the same temperature (185 °C) and shear rate (50 s −1 ), the apparent viscosity increased considerably with the raise of hard segment content, and the apparent viscosity and tensile strength of PPC-TPU with EG as chain extender was the maximum. It can be seen that with the apparent shear rate increasing, the variation tendency of apparent shear stress levels off, and the nonlinear relationship of τ – γ curve tended to be obvious. PPC-TPU exhibited a typical character of pseudoplastic non-Newtonian rheological behavior. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 45974.
研究领域:
高分子材料科学
·
流变学
·
功能高分子
·
生物基聚合物
·
材料力学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2016
·
IF 7.145
Juan Bai,Guang-Rui Xu,Shi-Hui Xing,Jing-Hui Zeng,Jia-Xing Jiang,Yu Chen
Ultrathin noble metal nanosheets with atomic thickness exhibit abnormal electronic, surfacial, and photonic properties due to the unique two-dimensional (2D) confinement effect, which have attracted intensive research attention in catalysis/electrocatalysis. In this work, the well-defined ultrathin Rh nanosheet nanoassemblies with dendritic morphology are synthesized by a facile hydrothermal method with assistance of poly(allylamine hydrochloride) (PAH), where PAH effectively acts as the complexant and shape-directing agent. Transmission electron microscopy and atomic force microscopy images reveal the thickness of 2D Rh nanosheet with (111) planes is only ca. 0.8–1.1 nm. Nitrogen adsorption–desorption measurement displays the specific surface area of the as-prepared ultrathin Rh nanosheet nanoassemblies is 139.4 m2 g–1, which is much bigger than that of homemade Rh black (19.8 m2 g–1). Detailed catalytic investigations display the as-prepared ultrathin Rh nanosheet nanoassemblies have nearly 20.4-fold enhancement in mass-activity for the hydrolysis of ammonia borane as compared with homemade Rh black.
研究领域:
无机化学
·
纳米材料学
·
催化化学
·
材料科学
·
物理化学
·
能源化学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2012
·
IF 2.103
Ling Zhu,Xiaoyan Liu,Tong Chen,Zhigang Xu,Wenfu Yan,Haixia Zhang
The periodic mesoporous organosilicas (PMO) with an organobridged ( CH 2 ) was synthesized and functionalized with amino or carboxylic groups by post-synthesis methods. The functionalized PMO by changing the hydrophilic/hydrophobic property and the net charge could be used to selectively adsorb and purify proteins with different shapes and different isoelectric points (pI). The experimental result showed that Bovine serum albumin (BSA) was adsorbed quicker than hemoglobin (Hb) on the materials, and lysozyme (Lys) could not be adsorbed on these PMO materials at all. The adsorption capacity of amino groups modified PMO (PMO-(NH 2 ) 2 ) for BSA was 44.67 mg/g and 300.0 mg/gfor Hb on carboxylic groups modified PMO (PMO-(COOH) 2 ). The adsorption behavior of proteins was affected strongly by the interaction among different constituents in the mixture of proteins. In addition, it is found that the adsorption rate of (PMO-(NH 2 ) 2 for adsorption of proteins was much slower than PMO-(COOH) 2 .
研究领域:
生物材料
·
纳米医学
·
蛋白质工程
·
分离科学
·
生物化学
✓ 已验证
DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2017
·Vol. 83
·期 2
·467-477
·
IF 1.575
Fu Likang,Zhang Libo,Wang Shixing,Zhang Gengwei,Peng Jinhui
A new adsorbent was synthesized via functionalizing nano-silica with 4-(aminomethyl) pyridine for selective recovery of gold. The adsorbent was characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy and transmission electron microscopy, and BET (surface area and porosimetry analyzer). The results indicated that the maximum adsorption capacity of Au(III) was 55.5 mg/g at pH 4.0 and room temperature. The adsorption reaction was fairly rapid and reached equilibrium within 30 min. The adsorption processes of Au(III) were fitted well to the Langmuir isotherm model and adsorption kinetics of Au(III) followed the pseudo-second-order rate equation. The adsorption mechanism lies on the chelation and ion exchange between gold ions and amines/hydroxyl groups. The adsorbent had good reusability after five cycles. Moreover, 4-(aminomethyl) pyridine-Silica nanoparticles has a good selectivity in the adsorption of Au(III) from the coexisting ions. Therefore, 4-(aminomethyl) pyridine functionalized nano-silica could be of great potential as new adsorbent for the selective recovery of Au(III) from industrial effluents and waste e-products. Graphical
研究领域:
环境化学
·
材料科学
·
冶金工程
·
污染控制
·
资源回收
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）