JOURNAL OF MATERIALS SCIENCE
·
2016
·Vol. 51
·期 22
·10229-10244
·
IF 2.302
Ban Jianfeng,Zhu Linjiang,Chen Shaojun,Wang Yiping
Aiming to elucidate the influence of liquid crystal fillers on the structure and properties of liquid-crystalline (LC) shape-memory polyurethane (SMPU) composites, a series of LC-SMPU composites are successfully prepared by adding various concentrations of 4-dodecyloxybenzoic acid (DOBA) to shape-memory polyurethane containing 40 wt% hard segment content (SMPU40). The structure, morphology, thermal properties, liquid crystalline properties, and shape memory properties are systematically investigated. The results demonstrate that DOBA is successfully incorporated into the polymer matrix of SMPU40 without interrupting the dimerization structure of DOBA that allows it to exhibit LC properties. The incorporated DOBA not only improves the crystallizability of the soft segment but also promotes the crystallizability of the hard segment. The isothermal crystallization kinetics further reveal that the crystallization rate of the hard segment decreases as the DOBA content increases, and the crystallization of the LC-SMPU composites nucleates in a similar manner. The LC-SMPU composites are composed of a DOBA phase and an SMPU phase, which further forms soft phase–hard phase microphase separation structures. The composite tends to only maintain the nematic LC properties of DOBA due to the interruption of polyurethane chains. However, the LC-SMPU composites exhibit good triple-shape memory effects. The first step of strain recovery is associated with the melting transition of soft segment crystals of the polyurethane matrix, and the second step of strain recovery is resulted from the melting transition of the DOBA crystals.
研究领域:
高分子材料科学
·
功能高分子
·
智能材料
·
软物质物理
·
材料化学
·
热分析
·
相变材料
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2016
·Vol. 52
·期 5
·2628-2641
·
IF 2.302
Ban Jianfeng,Zhu Linjiang,Chen Shaojun,Wang Yiping
In order to better understand the interrelation between liquid crystal fillers and functional polymers, a series of liquid crystalline shape memory polyurethane composites (LC-SMPUCs), named shape memory polyurethane (SMPU)–4-hexadecyloxybenzoic acid (HOBA) composites, are prepared by incorporating HOBA into SMPU based on a polyethylene glycol (PEG) soft segment. The results demonstrate that the dimerization structure of HOBA is maintained in the as-prepared SMPU–HOBA composites, facilitating liquid crystalline properties. Characterization results display smectic C phase upon heating, while the isotropic temperature shifts to a higher temperature, broadening the temperature range of the liquid crystalline phase. The SMPU–HOBA composites form a two-phase separated structure containing a SMPU phase and a HOBA phase; the incorporated HOBA can promote crystallizability of both soft and hard segments of SMPU, while crystalline hard phases are maintained within the high temperature range. Thus, SMPU–HOBA composites demonstrate a two-step modulus change upon heating that releases a triple-shape memory effect. The final shape fixing ratio is higher than 99%, and the final shape recovery ratio reaches 90%. Therefore, the SMPU–HOBA composites successfully provide a desirable combination of liquid crystalline properties and triple-shape memory properties, making them ideal candidates for smart sensor, smart labels, etc.
研究领域:
高分子材料科学
·
功能高分子
·
智能材料
·
软物质物理
·
材料化学
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DOI
高影响因子
Current Nanoscience
·
2020
·Vol. 16
·期 4
·617-624
·
IF 1.836
Feng Yao,Wang Ran,Yin Juanjuan,Zhan Fangke,Chen Kaiyue,Jiao Tifeng,Zhou Jingxin,Zhang Lexin,Peng Qiuming
Background: 4-nitrophenol (4-NP) is one of the pollutants in sewage and harmful to human health and the environment. Cu is a non-noble metal with catalytic reduction effect on nitro compounds, and has the advantages of simple preparation, abundant reserves, and low price. Carbon nanotubes
(CNT) are widely used for substrate due to their excellent mechanical stability and high surface area. In this study, a simple method to prepare CNT-Cu2O by controlling different reaction time was reported. The prepared nanocomposites were used to catalyze 4-NP. Methods: CNTs and CuCl2
solution were put into a beaker, and then ascorbic acid and NaOH were added while continuously stirring. The reaction was carried out for a sufficiently long period of time at 60°C. The prepared samples were dried in a vacuum at 50°C for 48 h after washing with ethyl alcohol and deionized
water. Results: Nanostructures of these composites were characterized by scanning electron microscope and transmission electron microscopy techniques, and the results at a magnification of 200 nanometers showed that Cu2O was distributed on the surface of the CNTs. In addition, X-ray diffraction
was performed to further confirm the formation of Cu2O nanoparticles. The results of ultraviolet spectrophotometry showed that the catalytic effect of the compound on 4-NP was obvious. Conclusions: CNTs acted as a huge template for loading Cu2O nanoparticles, which could improve the stability
and cycle performance of Cu2O. The formation of nanoparticles was greatly affected by temperature and the appropriate concentration, showing great reducibility for the 4-NP reduction reaction.
研究领域:
环境科学
·
材料科学
·
催化
·
纳米技术
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DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2018
·Vol. 85
·期 3
·506-513
·
IF 1.745
Fei Zhifang,Yang Zichun,Chen Guobing,Li Kunfeng
Abstract Polyimide cross-linked silica aerogels with different weight percentages of polyimide were prepared through sol–gel technology and supercritical CO 2 fluid drying technology. Tetraethoxysilane (TEOS) was used as a silica source precursor, 3-aminopropyltriethoxysilane (APTES) end-capped polyimide was used as a cross-linking agent, derived from 3, 3′, 4, 4′-biphenyltetracarboxylic dianhydride (BPDA) and 4, 4′-oxydianiline (ODA). The acid produced during the imidization process catalyzed the hydrolysis reaction without additional catalyst. After condensation reaction catalyzed by ammonium hydroxide solution, the polyimide cross-linked silica gels were obtained and then dried in supercritical CO 2 . The polyimide cross-linked silica aerogels have low density (0.132~0.187 g/cm 3 ), high specific surface area (623–741 m 2 /g), low thermal conductivity (0.0306~0.0347 W/m K at room temperature), relatively high compressive strength (1.03~3.82 MPa) and high thermal decomposition temperature (360 °C). This research provided a simple and efficient method that used the polyimide as a strengthening phase to improve the mechanical properties of TEOS-based silica aerogels.
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产品关联
DOI
高影响因子
Nanoscale Research Letters
·
2022
·Vol. 17
·期 1
·1-11
·
IF 5.418
Kadir Aygul,Jamal Ruxangul,Abdiryim Tursun,Liu Xiong,Zhang Hujun,Serkjan Nawrzhan,Zou Dongna,Liu Ya jun
In this work, we successfully assembled an organic–inorganic core–shell hybrid p-n heterojunction ultraviolet photodetector by the electropolymerization deposition of poly(3,4-ethylenedioxyselenophene) (PEDOS) on the surface of zinc oxide nanoarrays (ZnO NRs). The structures of composite were confirmed by FTIR, UV–Vis, XRD and XPS. Mott–Schottky analysis was used to study the p-n heterojunction structure. The photodetection properties of ZnO NRs/PEDOS heterojunction ultraviolet photodetector were systematically investigated current–voltage (I–V) and current–time (I–t) analysis under different bias voltages. The results showed that PEDOS films uniformly grew on ZnO NRs surface and core–shell structure was formed. The p-n heterojunction structure was formed with strong built-in electric field between ZnO NRs and PEDOS. Under the irradiation of UV light, the device showed a good rectification behavior. The responsivity, detection rate and the external quantum efficiency of the ultraviolet photodetector reached to 247.7 A/W, 3.41 × 10 12 Jones and 84,000% at 2 V bias, respectively. The rise time ( τ r ) and fall time ( τ f ) of ZnO NRs/PEDOS UV photodetector were obviously shortened compared to ZnO UV photodetector. The results show that the introduction of PEDOS effectively improves the performance of the UV photodetector.
研究领域:
材料科学
·
光电材料
·
有机-无机杂化材料
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DOI
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2014
·Vol. 173
·期 8
·2042-2053
·
IF 1.687
He Yu-Cai,Yang Zhen-Xing,Zhang Dan-Ping,Tao Zhi-Cheng,Chen Chao,Chen Yi-Tong,Guo Fei,Xu Jian-He,Huang Lei,Chen Rui-Jie,Ma Xiao-Feng
The reductase (PgCR) from recombinant Escherichia coli CCZU-Y10 displayed high reductase activity and excellent stereoselectivity for the reduction of ethyl 4-chloro-3-oxobutanoate (COBE) into ethyl ( S )-4-chloro-3-hydroxybutanoate (( S )-CHBE). To efficiently synthesize ( S )-CHBE (>99 % enantiomeric excess (ee)), the highly stereoselective bioreduction of COBE into ( S )-CHBE with the whole cells of E. coli CCZU-Y10 was successfully demonstrated in a dibutyl phthalate-water biphasic system. The appropriate ratio of the organic phase to water phase was 1:1 ( v / v ). The optimum reaction temperature, reaction pH, cosubstrate, NAD + , and cell dosage of the biotransformation of 100 mM COBE in this biphasic system were 30 °C, 7.0, mannitol (2.5 mmol/mmol COBE), 0.1 μmol/(mmol COBE), and 0.1 g (wet weight)/mL, respectively. Moreover, COBE at a high concentration of (1,000 mM) could be asymmetrically reduced to ( S )-CHBE in a high yield (99.0 %) and high enantiometric excess value (>99 % ee). Significantly, E. coli CCZU-Y10 shows high potential in the industrial production of ( S )-CHBE (>99 % ee).
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DOI
PubMed
高影响因子
JOURNAL OF CHROMATOGRAPHY A
·
2021
·
IF 4.759
Jingjing Han,Huiqi Wang,Zhanfeng Li,Zonghua Wang
Chitosan-modified magnetic Schiff base network composite nanospheres (Fe 3 O 4 @SNW@Chitosan) were prepared for the enrichment and detection of hippuric acid (HA) and 4-methyl hippuric acid (4-MHA) via magnetic solid phase extraction (MSPE) connected with HPLC. The SNW was one of the covalent organic framework, which constructed through covalent bonds, shown comprising solvent stability, low density and accessible pores. The obtained Fe 3 O 4 @SNW@Chitosan has many merits as a magnetic sorbent, including a hydrophilic surface, uniform pore size, unique ordered channel structure, and superparamagnetism. The favourable linearity of this MSPE-HPLC method was in the range of 1-1000 μg L −1 , and LODs of HA and 4-MHA were 0.3 μg L −1 and 0.2 μg L −1 , respectively. The recoveries in urine samples were range from 95.3 to 109.0 % with the RSD less than 9.6 %. When employed for the enrichment of HA and 4-MHA, Fe 3 O 4 @SNW@Chitosan exhibited great potential as a candidate for preconcentration.
研究领域:
分析化学
·
环境科学
·
医学检测
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DOI
高影响因子
ADSORPTION SCIENCE & TECHNOLOGY
·
2013
·
IF 0.559
Ping Yu,Qilong Sun,Jianming Pan,Zhenjiang Tan,Jiangdong Dai,Yongsheng Yan,Feng Cheng
Poly(styrene–divinylbenzene)/Fe3O4 (Fe3O4@St–DVB) magnetic porous polymer microspheres based on suspension polymerization were prepared for adsorption of 2, 4-dichlorophenol (2, 4-DCP) and 2, 6-dichlorophenol (2, 6-DCP) from aqueous solution. The as-prepared product was characterized by Fourier transform infrared spectroscopy, Raman, X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, differential thermal analysis and elemental analysis. The results showed that the composite material has both porous and magnetic characteristics, which aid in faster separation and increase in adsorption capacity. The adsorption performance of the Fe3O4@(St–DVB) magnetic porous microspheres was manifested by batch mode adsorption experiments with respect to pH, initial concentration, contact time and temperature. The adsorbent was found to be sensitive to changes in pH, and the adsorption capacity of 2, 4-DCP is higher than that of 2, 6-DCP. The kinetics experimental data fitted well with the pseudo-second-order model, as three steps belonged to the pseudo-second-order adsorption process. The adsorption isotherms were also described by the Langmuir and Freundlich isotherm models, respectively. It was found that the Langmuir isotherm model fitted the equilibrium data superior to the Freundlich model. Thermodynamic parameters were calculated by the Gibbs free energy function, confirming that adsorption process was spontaneous and endothermic. In addition, the reusability performance of the Fe3O4@(St–DVB) magnetic porous microspheres was demonstrated by four repeated cycles.
研究领域:
环境科学
·
材料科学
·
化学工程
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DOI
高影响因子
Journal of Water Process Engineering
·
2023
·
IF 7
Zijun Xie,Bo Sun,Hongying Lin,Meng Fu,Yi Zhang,Zequn Ma,Xiangming Li
Dephosphorylation that separates phosphate groups from substrates is a significant reaction for both living organisms and environmental protection. Meanwhile, 4-nitrophenol (4-NP) is known to be a popular organic compound used for pesticides production, which is genotoxic and carcinogenic to humans and animals. Herein, we have developed a bifunctional catalyst that can be used for simultaneous dephosphorylation and 4-nitrophenol (4-NP) reduction when para-nitrophenyl phosphate (p-NPP) serves as the model compound. This bifunctional catalyst was obtained by in-situ growth of NiFe layered double hydroxide on the reduced graphene oxide/polyelectrolytes assembly nanolayers (denoted as rGP 3.5 /NiFe LDH). The results demonstrate that the rGP 3.5 /NiFe LDH can activate dephosphorylation of p-NPP at 20 °C and the catalytic efficiency increases significantly with increasing temperature in the range of 20 °C to 90 °C. Moreover, by-product 4-NP formed through p-NPP dephosphorylation is further fully converted to 4-aminophenol by the rGP 3.5 /NiFe LDH within 15 min. As far as we know, this is the first example for both dephosphorylation and 4-NP reduction through NiFe LDH as bifunctional catalysts, which paves the way for the development of multiple potential applications for NiFe LDH.
研究领域:
催化
·
环境化学
·
材料科学
·
纳米技术
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DOI
高影响因子
Optical Materials Express
·
2021
·Vol. 11
·期 9
·3015-3022
·
IF 3.442
Xiangfa Kong,Chaohui Cheng,Qifan Wang,Mianwu Meng,Mianwu Meng,Chaoshu Chen,Xiujian Wang,Siyu Huang,Siyu Huang,Siyu Huang,Weixin Gan,Weixin Gan
A Au-Ga alloy layer is synthesized on a Au sheet substrate at low temperature and a new nanoporous Au material is then prepared based on Ga removal from the Au-Ga alloy by a electrochemical method. X-ray diffraction analysis confirms that the grains of the newly formed Au layer are refined and scanning electron microscopy suggests that the newly formed Au layer has a nanoporous structure with a pore size of∼16 nm. The cyclic voltammetry curve of the prepared nanoporous Au in a 1 M KCl solution presents a square structure of a supercapacitor with a specific capacitance of mF·cm-2, which is 86 times that of the smooth Au electrode. The 4-mercaptobenzoic acid (4-MBA) modified nanoporous Au material is used as a Raman substrate to detect Hg2+ with surface-enhanced Raman scattering. from 1.0×10−10 mol·L-1 to 1.0×10−5 mol·L-1), and the limit of detection is 1.0×10−10 mol·L-1.
研究领域:
材料科学
·
分析化学
·
纳米技术
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DOI
高影响因子
Nano Research
·
2024
·
IF 9.5
Zhu Shengjie,Huang Danqing,Luan Qichen,Li Yang,Gan Jingjing,Zhao Yuanjin,Sun Lingyun
Macrophages play a pivotal role in systemic lupus erythematosus (SLE) therapy. Efforts have been made to develop multifunctional drug delivery systems capable of directing macrophage polarization. Here, we present a novel hyaluronic acid methacrylate (HAMA) hydrogel microparticle encapsulating multiple cytokines for SLE remission though enhancing macrophage functions. The HAMA microparticles loaded with monocyte chemotactic protein-1 (MCP-1) and interleukin-4 (IL-4) were fabricated by using a microfluidic technology. The released MCP-1 facilitates the aggregation of inflammatory macrophages, after which IL-4 induces the macrophage phenotype shift from inflammatory M1 to immune-protective M2, thus restoring immune balance. We have demonstrated in MRL/lpr mice that the hydrogel microparticles could improve their efficacy of intraperitoneal drug delivery, modulate immune function, and attenuate the disease symptoms. These results suggest that our proposed microparticles delivery platform has potential clinical value for treating autoimmune diseases.
研究领域:
药理学
·
免疫学
·
生物医学工程
·
药物递送系统
·
自身免疫疾病
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DOI
高影响因子
MICROCHIMICA ACTA
·
2021
·Vol. 188
·期 5
·1-11
·
IF 5.833
He Yanlei,Li Ning,Liu Xiangwei,Chen Wei,Zhu Xixi,Liu Qingyun
Urchin-like peroxidase mimics 5,10,15,20-tetrakis (4-carboxyl phenyl) porphyrin–functionalized CuCo 2 O 4 nanospheres (Por-CuCo 2 O 4 ) has been fabricated as an excellent visual biosensor. X-ray diffractometry (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) have been employed to characterize the composition, morphologies, and elemental analysis of the as-synthesized Por-CuCo 2 O 4 . The catalytic activity of Por-CuCo 2 O 4 was evaluated by the chromogenic substrate 3,3′,5,5′-tetramethylbenzidine (TMB) with the aid of H 2 O 2 , which exhibited a visual blue change with an absorption maximum at 652 nm for only 10 s. The peroxidase-like behaviors of Por-CuCo 2 O 4 conformed to the Michaelis-Menten equation. Electrochemistry, radical scavenger, and fluorescence probe experiments verified that electron transfer, •O 2 − radicals, and holes (h + ) are the important factors during the catalytic oxidation of TMB. Based on the inhibition of dopamine (DA) on TMB oxidation, the Por-CuCo 2 O 4 -based colorimetric biosensor has been successfully constructed for sensitive determination of DA witha detection limit (LOD) of 0.94 μΜ. In addition, colorimetry was validated to detect DA in serum samples with high sensitivity and good selectivity. Graphical abstract
5,10,15,20-tetrakis (4-carboxyl phenyl) porphyrin–functionalized urchin-like CuCo 2 O 4 (Por-CuCo 2 O 4 ) with excellent peroxidase activity, ascribed to the synergistic effect between •O 2 − radicals and holes (h + ). A fast colorimetric sensor on the basis of Por-CuCo 2 O 4 has been constructed to quantitatively determine dopamine concentration in human serums.
研究领域:
纳米技术
·
生物传感器
·
分析化学
·
材料科学
·
生物化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）