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
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
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
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
ENVIRONMENTAL POLLUTION
·
2020
·
IF 6.793
Cui Ma,Shengyong Jia,Pengfei Yuan,Zhengguang He
Composite magnetic oxide at cow dung ash, nano-Fe 3 O 4 @cow dung ash (nano-Fe 3 O 4 @CDA), was used as catalytic material for the degradation of 2, 2′-methylenebis (4-methyl-6-tert-butylphenol) (AO 2246) in real biologically pretreated landfill leachate . The Fe 3 O 4 @CDA composite exhibited catalytic ozonation activity and allowed material separation and magnetic recovery. The effects of several operating parameters including O 3 concentration, catalyst dosage, temperature and scavengers were evaluated in parallel. Over 70% of AO 2246 were removed by the nano-Fe 3 O 4 @CDA/O 3 system under optimum conditions within 120min reaction time. The EPR, GC–MS and free-radical quenching experiments expatiated the mechanism of this degradation process. It was confirmed that the AO 2246 was degraded efficiently in this catalytic micro-ozonation process, Additionally, GC–MS analysis state clearly that the 3,5-bis(1,1-dimethylethyl)phenol, 4-(1,5-dihydroxy-2,6,6-trimethylcyclohex-2-enyl)but-3-en-2-one, ethanone, 1-(1,4-dimethyl-3-cyclohexen-1-yl)-, 5-tert-butyl-6-3, 5-diene-2-one, 2-hydroxyhexanoic acid, 2-propenoic acid 1,1-dimethylethyl ester, butanoic acid, 2-methyl-, methyl ester and propanoic acid, 2, 2-dimethyl- were the dominant oxidation products (OPs) during the degradation of the AO 2246. The EPR results showed that the catalytic ozonation over Fe 3 O 4 @CDA led to produce more hydroxyl radicals , which were in favor of AO 2246 degradation. The toxicity evolution was also performed through a QSAR analysis calculated by the ECOSAR program which further demonstrated the different responses toward the AO 2246 and its OPs.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
ANALYTICA CHIMICA ACTA
·
2012
·
IF 4.555
Tao Li,Haoyue Xie,Zhifeng Fu
A facile, sensitive and universal method was established for analysis of biogenic amines using micellar electrokinetic chromatography coupled with chemiluminescent (CL) detection. It was found that diperiodatocuprate (III) (K 5 [Cu(HIO 6 ) 2 ], DPC), a transition metal chelate at unstable high oxidation state, could effectively enhance the reaction between luminol-type compound and hydrogen peroxide, to produce very strong CL signal. In addition, triethylamine was found to be able to effectively improve the yield of the derivatization reaction between biogenic amines and a luminol-type derivatization reagent, N -(4-aminobutyl)- N -ethylisoluminol (ABEI). Based on these facts, three biogenic amines were pre-column derivatized with ABEI, and post-column detected using high sensitive luminol-hydrogen peroxide-DPC CL system. Since the background was quite low, and the signal was quite strong, a considerable improved sensitivity was obtained. The presented method had been successfully applied to simultaneously analyze glycine, proline and phenylalanine with the detection limits (S/N = 3) of 0.030 μmol L −1 , 0.23 μmol L −1 and 0.21 μmol L −1 , respectively. To evaluate its potential application value, glycine in saliva and urine samples was detected using this method, and satisfied results were obtained. This approach can be further extended to detection of many other compounds such as peptides and drugs by using luminol-type derivatization reagent.
研究领域:
分析化学
·
生物化学
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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
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2022
·Vol. 12
·期 8
·2482-2489
·
IF 6.177
Nan Sun,Yong Zhang,Xinru Li,Yuhan Jing,Zhengdong Zhang,Yu Gao,Jianqi Liu,Honglin Tan,Xiaoming Cai,Jinming Cai
Copper-based photocatalysts have attracted considerable attention because of their great prospects in photochemical conversions. However, there are still challenges faced during the preparation of copper-based photocatalysts with have high catalytic efficiency and high stability. In this study, polyaniline (PANI) was doped in an ultra-thin graphitized polyacrylonitrile (g-PAN) layer (denoted as CI), and Cu nanoparticles (NPs) were wrapped in the CI layer encapsulated on SrTiO3 (STO), which is designed as an efficient and low-cost photocatalyst for photocatalytic hydrogen production under visible light irradiation. Benefiting from the unique CI layer structure, the optimized Cu@CI/STO photocatalytic hydrogen evolution rate obtained was 371 μmol g−1 h−1, which is higher than the hydrogen evolution rate of Cu@g-PAN/STO (265.25 μmol g−1 h−1). Moreover, the CI layer demonstrated a quasi-cocatalyst effect. The ultra-thin CI layer not only protects the Cu NPs from oxidation but also promotes charge separation, which distinctly boosts H2 evolution, as indicated by the photoluminescence emission spectra, EIS Nyquist diagram and Mott–Schottky diagram. In addition, the degradation rate of Cu@CI/STO is approximately 4-fold higher than that of Cu/STO in the photocatalytic degradation of 4-nitrophenol under visible light. This study delivers a new method to protect Cu NPs and demonstrates the prospect for the rational design of copper-based photocatalysts with high stability and efficiency.
研究领域:
材料科学
·
环境科学
·
化学工程
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DOI
高影响因子
FOOD CHEMISTRY
·
2021
·
IF 7.514
Ghulam Mujtaba Mari,Hongfang Li,Baolei Dong,Huijuan Yang,Aisha Talpur,Jiafei Mi,Liuchuan Guo,Xuezhi Yu,Yuebin Ke,Diangang Han,Zhanhui Wang
Derivatization is usually employed in immunoassay for detection of metabolites of nitrofurans and avoiding derivatization could be preferable to achieve an efficient screening. In the study, we designed four haptens of 4-hydroxybenhydrazide (HBH), the nifuroxazide metabolite. The effect of hapten structures on antibody affinity were evaluated and one monoclonal antibody was produced by using the Hapten C with a linear alkalane spacer arm. After optimization, an enzyme linked-immunosorbent assay (ELISA) was established with an 50% inhibition concentration of 0.25 ng mL −1 for HBH, which could ensure the direct detection of HBH without derivatization. The limit of detection of the ELISA for HBH was 0.12 µg kg −1 with the recoveries of 90.1–96.2% and coefficient of variation (CV) values lower than 9.1%. In conclusion, we produced several high affinity antibodies to HBH with new designed hapten and developed an icELISA for the direct detection of HBH without derivatization in chicken.
研究领域:
分析化学
·
免疫学
·
兽医学
·
食品安全
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DOI
PubMed
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
危险品化学品经营许可证（带存储）