REACTIVE & FUNCTIONAL POLYMERS
·
2016
·
IF 2.725
Guanghua He,Wanwan Ke,Xiang Chen,Yahui Kong,Hua Zheng,Yihua Yin,Weiquan Cai
Quaternary ammonium chitosan- g -poly(acrylic acid- co -acrylamide) superabsorbent hydrogels were successfully synthesized from acrylic acid (AA), acrylamide (AM) and quaternary ammonium chitosan with high substitution degree. They were prepared using potassium persulfate (KPS) as an initiator and N , N ′-methylenebisacrylamide (MBA) as a crosslinker respectively. The structure and morphology of the superabsorbent hydrogel were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The water absorbency and antibacterial activities of the superabsorbent hydrogels against Escherichia coli ( E. coli ) and Staphylococcus aureus ( S. aureus ) were investigated. The introduction of quaternary ammonium chitosan made the antibacterial activity improve. The crosslinker, initiator and AM contents had certain influences on the water absorbency as well as the antibacterial activity against E. coli . The AM could enhance the hydrogel strength apparently. In addition, the AM (the content was 10 wt%) could increase the water absorbency in 0.9 wt% NaCl solution obviously. The superabsorbent hydrogel also had pH sensitive property.
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JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2017
·Vol. 164
·期 13
·F1483
·
IF 3.259
Yingjie Chen,Shiben Liu,Zhihao Shi,Jianhua Yu,Hongzhou Dong,Yong Qin,Liyan Yu,Lifeng Dong
Ag-MFe2O4 (M = Co, Mn) nanocomposites were synthesized and loaded onto carbon supports. As-prepared Ag-MFe2O4/C demonstrated higher catalytic activity for oxygen reduction reaction (ORR) than Ag+MFe2O4/C. The direct coupling and electron transfer between Ag and MFe2O4 in nanocomposites were proposed to enhance their catalytic activities. The Koutecky-Levich plots confirmed a direct four-electron reaction pathway for the ORR on Ag-MFe2O4/C. Furthermore, Ag-MFe2O4/C showed superior catalytic activities and excellent stability for oxygen evolution reaction (OER). Thus, Ag-MFe2O4/C nanoparticle are potential non-Pt candidates with bi-functional catalytic activity for ORR and OER.
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高影响因子
RSC Advances
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2017
·Vol. 7
·期 72
·45280-45286
·
IF 3.108
Bo Tang,Guojian Ji,Zhengwei Wang,Haiqun Chen,Xufei Li,Haogang Yu,Sen Li,Hong Liu
Graphene assisted dye-sensitized solar cells (DSSCs) have drawn increasing attention because of their high performances. However, two bottlenecks (the high defect density and the discontinuous structure) of the widely adopted reduced graphene oxide (RGO) nanosheets bring about that the practical photovoltaic properties are far inferior to the theoretical prediction values. Therefore, three-dimensional graphene networks (3DGNs) of high quality have been employed to modify DSSCs to avoid the above mentioned problems. However, a close contact between the graphene basal plane and TiO2 particles in the resulting photoanode is difficult to achieve due to the absence of surface functional groups of the 3DNG. In this study, the RGO nanosheets and 3DGNs co-modified DSSCs are prepared, and the advantages from these two modifiers can give full play to their synergy. The added RGO nanosheets enhance the electron transport ability at the interfaces between graphene, TiO2 and conductive substrate. After optimizing the reduction degree and mass fraction of the RGO nanosheets, the power conversion efficiency of the resulting DSSC reaches 7.68%, which is much higher than those cases of using the 3DGNs (or RGO nanosheets) as modifier alone.
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CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Yan Chao Xu,Zhen Xing Wang,Xi Quan Cheng,You Chang Xiao,Lu Shao
Herein, a novel positively charged nanofiltration (NF) membrane has been facilely fabricated via a highly efficient one-step mussel-substance-simulated co-deposition of low-cost catechol and branched polyetheylenimine (PEI) onto substrates. The co-deposition behaviour, physicochemical properties and separation performances of resultant membranes can be readily tailored by varying PEI molecular weight. In particular, the catechol/PEI600 co-deposited NF membrane shows good removals toward dyes, common salts and heavy metal ions for textile wastewater treatment. Our membranes exhibit high removal efficiency toward cationic dye and metal ions due to the Donnon effect. In addition, EtOH activation process can greatly enhance the membrane permeance with a factor of 1.8–2.4 without compromising rejection. Especially, the novel membranes show stable long-term separation performance toward MgCl 2 removal, and the dye-fouled co-deposited membranes can be facilely regenerated and reused with a simple static immersion operation. The co-deposited membrane can perform well in alcohols solvents, indicating its excellent performance for practically environmentally-friendly usages. The facile strategy disclosed in our study can provide new opportunities to not only nanofiltration membrane modification but also the surface engineering of vast kinds of materials towards energy and environmental applications.
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Progress in Natural Science-Materials International
·
2016
·
IF 1.753
Yu Bai,Chunlei Wang,Xingyi Zhou,Junling Lu,Yujie Xiong
Pd typically exhibits relatively low catalytic activity in CO oxidation, as CO is apt to be adsorbed on Pd to poison the surface for O 2 activation. In this Letter, we report that this limitation can be overcome by integrating Pd with TiO 2 . The TiO 2 was coated on Pd nanocubes with a controllable thickness using atomic layer deposition (ALD) method. Given the different work functions of TiO 2 and Pd, the electrons in TiO 2 semiconductor will flow toward Pd. With the electron density increased on Pd, the adsorption of CO to Pd will be weakened while the oxygen activation can be facilitated. Meanwhile, the interface-confined sites at Pd-TiO 2 may further enhance the oxygen activation. As the species adsorption and activation are strongly correlated with electron density, the performance of Pd-TiO 2 in CO oxidation turns out to depend on the TiO 2 thickness, which determines the number of transferred electrons, within a certain range (<1.8 nm). This work provides a new strategy for enhancing catalytic performance through tailoring charge densities in hybrid catalysts.
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BIOTECHNOLOGY AND BIOENGINEERING
·
2017
·Vol. 115
·期 1
·60-69
·
IF 4.481
Gang Liu,Qiang Zhang,Hongxing Li,Abdul S. Qureshi,Jian Zhang,Xiaoming Bao,Jie Bao
Despite the well-recognized merits of simultaneous saccharification and co-fermentation (SSCF) on relieving sugar product inhibition on cellulase activity, a practical concomitance difficulty of xylose with inhibitors in the pretreated lignocellulose feedstock prohibits the essential application of SSCF for cellulosic ethanol fermentation. To maximize the SSCF potentials for cellulosic ethanol production, a dry biorefining approach was proposed starting from dry acid pretreatment, disk milling, and biodetoxification of lignocellulose feedstock. The successful SSCF of the inhibitor free and xylose conserved lignocellulose feedstock after dry biorefining reached a record high ethanol titer at moderate cellulase usage and minimum wastewater generation. For wheat straw, 101.4 g/L of ethanol (equivalent to 12.8% in volumetric percentage) was produced with the overall yield of 74.8% from cellulose and xylose, in which the xylose conversion was 73.9%, at the moderate cellulase usage of 15 mg protein per gram cellulose. For corn stover, 85.1 g/L of ethanol (equivalent to 10.8% in volumetric percentage) is produced with the overall conversion of 84.7% from cellulose and xylose, in which the xylose conversion was 87.7%, at the minimum cellulase usage of 10 mg protein per gram cellulose. Most significantly, the SSCF operation achieved the high conversion efficiency by generating the minimum amount of wastewater. Both the fermentation efficiency and the wastewater generation in the current dry biorefining for cellulosic ethanol production are very close to that of corn ethanol production, indicating that the technical gap between cellulosic ethanol and corn ethanol has been gradually filled by the advancing biorefining technology.
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PubMed
高影响因子
Small
·
2016
·Vol. 13
·期 3
·1602507
·
IF 8.315
Feng Hu,Hongchao Yang,Changhong Wang,Yejun Zhang,Huan Lu,Qiangbin Wang
Rational design of cost-effective, nonprecious metal-based catalysts with desirable oxygen reduction reaction (ORR) performance is extremely important for future fuel cell commercialization, etc. Herein, a new type of ORR catalyst of Co-N-doped mesoporous carbon hollow sphere (Co-N-mC) was developed by pyrolysis from elaborately fabricated polystyrene@polydopamine-Co precursors. The obtained catalysts with active Co sites distributed in highly graphitized mesoporous N-doped carbon hollow spheres exhibited outstanding ORR activity with an onset potential of 0.940 V, a half-wave potential of 0.851 V, and a small Tafel slope of 45 mV decade −1 in 0.1 m KOH solution, which was comparable to that of the Pt/C catalyst (20%, Alfa). More importantly, they showed superior durability with little current decline (less than 4%) in the chronoamperometric evaluation over 60 000 s. These features make the Co-N-mC one of the best nonprecious-metal catalysts to date for ORR in alkaline condition.
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PubMed
高影响因子
Journal of Materials Chemistry C
·
2016
·Vol. 4
·期 42
·10154-10160
·
IF 5.066
J. L. Wang,E. H. Song,M. Wu,W. B. Dai,X. F. Jiang,B. Zhou,Q. Y. Zhang
Room-temperature green to orange color-tunable upconversion (UC) luminescence has been achieved from Yb3+/Mn2+ co-doped CaO by adjusting the doping concentration of Mn2+ ions and the temperature of the samples upon 980 nm laser diode excitation. In this material system, the green UC emission band centered at 508 nm and the wavelength-tunable orange UC emission band from 560 to 725 nm are realized at 980 nm excitation, which originate from the cooperative luminescence of Yb3+ pairs and the |2F7/2, 4T1(4G)〉 → |2F7/2, 6A1(S)〉 transition of exchange-coupled Yb3+–Mn2+ dimers, respectively. The characteristic Stokes and UC emission properties, UC luminescence decay behaviors, temperature-dependent UC emission properties, as well as the involved UC mechanism of CaO:Yb3+,Mn2+ are investigated and discussed in detail. This study offers a new method to design novel UC materials for lighting and display applications instead of using conventionally investigated lanthanide (Ln3+) ions, such as Er3+, Tm3+ and Ho3+.
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Journal of Materials Chemistry C
·
2016
·Vol. 4
·期 41
·9738-9749
·
IF 5.066
Peijiang Liu,Zhengjun Yao,Jintang Zhou,Zhihong Yang,Ling Bing Kong
In this study, novel CNZF (Co-doped Ni–Zn ferrite)/GN (graphene) nanocomposites were prepared by using a facile one-pot hydrothermal method. The phase structure, morphology, and magnetic and electromagnetic performance of the nanocomposites were studied by means of modern measurement techniques. Both sides of the GN sheets were densely covered by CNZF nanoparticles. Moreover, the magnetic nanoparticles had a uniform distribution without the presence of significant agglomeration. The electromagnetic performance indicated that the content of GN played a significant role in determining the dielectric behavior and magnetic anisotropy of the carbon materials, which further influenced the impedance matching and attenuation ability of absorbers. The microwave absorption properties showed that the CNZF/GN-10 nanocomposite exhibited dual-region microwave absorption, with two strong reflection loss peaks of −53.5 dB and −58.3 dB at 9.6 GHz and 5.2 GHz, respectively. The effective absorption bandwidths were as wide as 14.8 GHz, with thicknesses in the range of 1.5–6.0 mm. In addition, such dual-region absorption performance was also observed in CNZF/GN nanocomposites with other compositions. The appearance of dual-region absorption and the mechanism of microwave absorption were discussed in detail. It is expected that this CNZF/GN nanocomposite can be used as a new type of an efficient microwave absorber with light weight.
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FUEL
·
2016
·
IF 3.611
Panpan Yang,Qineng Xia,Xiaohui Liu,Yanqin Wang
Catalytic transfer hydrogenation/hydrogenolysis of 5-hydroxymethylfurfural (HMF) to valuable chemicals, 2,5-dimethylfuran (DMF), is realized over a carbon supported nickel-cobalt catalyst with formic acid as hydrogen donor. The highest DMF yield, 90.0%, is achieved at 210 °C under self-generated pressure. A reaction route involving 5-methylfurfural (5-MF) instead of 2,5-bis(hydromethyl)furan (BHMF) as an intermediate has been investigated, which is different from that when H 2 is used as hydrogen source in previous reports. The influence of the amount of formic acid is investigated on the conversion of HMF and the yield of DMF. The effectiveness of this strategy has also been used for the conversion of furfural to 2-methylfuran, another valuable chemicals.
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Materials Science & Engineering C-Materials for Biological Applications
·
2016
·
IF 3.42
Yaming Gu,Yizhen Guo,Changyong Wang,Jiake Xu,Jianping Wu,Thomas Brett Kirk,Dong Ma,Wei Xue
It is a promising way to treat the multi drug resistance (MDR) of tumor cells in both of drug and gene methods. A polyamidoamne dendrimer functionalized graphene oxide (GO-PAMAM) was designed, which could load doxorubicin (DOX) and MMP-9 shRNA plasmid at the same time in order to achieve effective treatment to breast cancer. GO-PAMAM has a high loading capacity to DOX and pH-controlled DOX release. Besides, it has efficient gene transfer ability, the transfection efficiency is significantly better than PEI-25k in the presence of serum, and it can significantly inhibit the expression of MMP-9 protein in MCF-7 cells. The effect of DOX and MMP-9 shRNA plasmid co-delivery was more significant than that of the single drug. Moreover, GO-PAMAM exhibited lower cytotoxicity compared to PEI-25k in CCK-8 assays, and also showed a good biocompatibility in vivo . Therefore, GO-PAMAM will have broad prospects for drug and gene co-delivery.
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PubMed
高影响因子
MATERIALS RESEARCH BULLETIN
·
2017
·
IF 2.446
Kun He,Zewen Ruan,Xiangguo Teng,Yongming Zhu
Spherical nickel rich layer cathode materials (LiNi 0.85− x Co 0.15 Al x O 2 ( x = 0.02, 0.05 and 0.10), NCA) with excellent electrochemical performance for high energy densities lithium-ion batteries are successfully synthesized by a continuous co-precipitation method. An elaborate design of Al solution with sodium aluminate is successfully adopted, which can efficiently prevent rapid precipitation of Al(OH) 3 and obtain the precipitated precursors. The thermodynamic model is established in the Ni—Co—Al—NH 3 —H 2 O system and investigation of precipitation mechanism is carried out systematically, and the results demonstrate that the spherical LiNi 0.85− x Co 0.15 Al x O 2 can be obtained through this route. Charge and discharge tests show that LiNi 0.85− x Co 0.15 Al x O 2 synthesized has a high initial discharge specific capacity of 208 mAh/g at 0.1 C and a good capacity retention of 90.2% after 200 cycles at 0.5 C between 2.5 and 4.3 V. It is expected that performance of NCA electrodes for advancing lithium-ion batteries could be improved with the new process proposed in this study.
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