JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
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2014
·Vol. 70
·期 3
·355-360
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IF 1.547
Gao Xiaoju,Cui Hongtao
Herein, addition reaction occurred between glycidol and partially hydrolyzed Ti 4+ complexes provides a opportunity to obtain dry anatase nanopowder with high redispersity in water. This property is considered to be originated from the two OH groups located in the two ends of glycidol resulted chlorinated propandiol molecules. In aqueous solution, the two OH groups are respectively connected with particle surface and external free water by the formation of hydrogen bonds, resulting in high water redispersity of nanoparticles. Due to the much less amount of chlorinated propandiol molecules than adsorbed molecule water on particle, the wide space between organic molecules facilitates the mutual physical surface touch of individual particles to form hydrogen bond between them. A novel property is then obtained for surface modified titania nanoparticles, which is the gelation of redispered nanoparticles in aqueous solution.
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高影响因子
JOURNAL OF POWER SOURCES
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2015
·
IF 6.217
Tao Yang,Guojian Cao,Qingli Huang,Yanxia Ma,Sheng Wan,Hong Zhao,Na Li,Fujun Yin,Xia Sun,Dongen Zhang,Mingyan Wang
In present work, truncated octahedral Pt–Ni–Ir ternary nanoparticles with an average size of 10 nm and a Pt/Ni/Ir atomic ratio of 55/29/16 are synthesized through a facile method. Structural measurements show that the nanoparticles are surface Ni-scarce Pt–Ni–Ir ternary nanostructures . The mass activity and specific activity of the ternary catalyst are 511 mA mg −1 (Pt) and 1.03 mA cm −2 at 0.9 V (vs. reversible hydrogen electrode , RHE), respectively, which are nearly 4.8 and 6.0 times larger than that of the commercial Pt/C catalyst (106 mA mg −1 and 0.17 mA cm −2 ). After duration test of 10,000 cycles at the potential range from 0.6 to 1.0 V, the ternary catalyst preserved 66% and 73% of its initial mass activity and specific activity, respectively, which are 9 and 7.6 times that of the commercial Pt/C catalyst (37.2 mA mg −1 and 0.0998 mA cm −2 , respectively) after the same durability examination. The dramatic enhancement of Pt–Ni–Ir ternary catalyst can be attributed to its morphology, composition and nanostructure. Our research suggests that Pt–Ni–Ir ternary catalyst could be an excellent candidate for ORR . Our investigation might also spur increasing attention to tailoring morphology and composition of ternary or multi-metallic nanostructure with high electro-catalytic performance.
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JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2014
·Vol. 52
·期 20
·2998-3003
·
IF 3.245
Jinbao Xu,Weizhen Lian,Stergios Pispas,Guangzhao Zhang
A facile one-pot 1,8-diazacyclo-[5,4,0]undec-7-ene (DBU) catalyzed transesterification/atom transfer radical polymerization (ATRP) strategy has been successfully developed through the combination of copper/DBU-catalyzed ATRP and DBU-catalyzed transesterification reactions. Well-defined poly(methacrylate)s with various side ester groups have been synthesized by ATRP and transesterification of acyl donor 2,2,2-trifluoethyl methacrylate with various alcohols, such as benzyl alcohol, n -butanol, iso -propyl alcohol, methanol, triethylene glycol monomethyl ether, propargyl alcohol, and 6-azido-1-hexanol by the one-pot process. Kinetic studies indicate that the ATRP process proceeded in a controllable manner without the interference of the transesterification reactions. Expansion of the binary system to a higher level ternary system has been successfully achieved by the combination of copper(I)-catalyzed azide–alkyne cycloaddition, transesterification, and ATRP reactions. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52 , 2998–3003
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JOURNAL OF NANOPARTICLE RESEARCH
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2014
·Vol. 16
·期 9
·1-9
·
IF 2.278
Cui Hongtao,Xue Junying,Ren Wanzhong,Wang Minmin
In this work, β-Ni(OH) 2 monolayer nanosheets were prepared in benzyl alcohol by a facile exfoliation-free sol–gel route. The hydrolysis reaction of metal ions was started with the ring-opening reaction of epoxide. The in situ modification of benzyl alcohol molecules on the surface of secondary growth unit of hydroxide allowed the formation of β-Ni(OH) 2 monolayer nanosheets and 100 % monolayer state of β-Ni(OH) 2 in the resultant suspension. As proven in the electrochemical measurement, the maximum specific capacitance of 1735 F g −1 was obtained at scan rate of 5 mV s −1 within potential window of 0.6 V in 6 mol l −1 KOH aqueous solution, which is equal to the theoretical value of β-Ni(OH) 2 . This high electrochemical performance is attributed to the complete exposure of every structure unit of β-Ni(OH) 2 to electrolyte. This work demonstrates that monolayer nanosheets can generate from the brucite-type nickel hydroxide through this bottom-up strategy although it had been theoretically considered to be impossible.
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Materials Science & Engineering C-Materials for Biological Applications
·
2015
·
IF 3.088
Manqing Yan,Hongjun Yang,Guangzhao Zhang
A novel biocompatible and biodegradable copolymer was synthesized by one-step hybrid copolymerization of ε -caprolactone (CL) and 2-( N , N -dimethylamino) ethyl methacrylate (DMAEMA) employing (1-tert-butyl-4,4,4-tris(dimethylamino)-2,2-bis[tris(dimethylamino)phophoranylidenamino]-2Λ5,Λ5-catenadi(phosphazene) ( t -BuP 4 ) as a catalyst. The as-synthesized copolymer was betainizated resulting in a zwitterionic copolymer poly (CL- co - z DMAEMA) and the structure of the zwitterionic copolymer was confirmed by the FT-IR, NMR, and XPS measurements. The results of dynamic light scattering (DLS) show that this zwitterionic copolymer can self-assemble into stable micelles. The results of quartz crystal microbalance with dissipation (QCM- D ) analysis and MTT measurement suggest that this zwitterionic copolymer possess better protein resistance and lower cell cytotoxicity in vitro in comparison with the cationic copolymer. The pyrene solubilization measurement of copolymers poly (CL- co - z DMAEMA) indicates an excellent pyrene solubilization capacity. These zwitterionic polymer micelles can release drugs in response to specific signals, such as temperature, pH, and enzymes and have a potential application in drug delivery and gene therapy due to their good antifouling, low cytotoxicity and high pyrene solubilization.
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高影响因子
BIOCONJUGATE CHEMISTRY
·
2015
·
IF 4.513
Mingzhi Wang,Chuncai Zhou,Jing Chen,Yufen Xiao,Jianzhong Du
Cancer patients after chemotherapy may also suffer bacterial attack due to badly decreased immunity. Although with high bacterial efficacy, conventional antibiotics are prone to inducement of drug resistance and may be not suitable for some cancer patients. In contrast, antibacterial peptides are highly effective in inhibiting bacteria without inducing resistance in pathogens. Presented in this article is a novel kind of highly effective antibacterial peptide-based biocompatible and biodegradable block copolymer vesicle. The copolymer is poly(ε-caprolactone)-block-poly[phenylalanine-stat-lysine-stat-(lysine-folic acid)] [PCL19-b-poly[Phe12-stat-Lys9-stat-(Lys-FA)6]], which can self-assemble into vesicles in aqueous solution. The biocompatible and biodegradable PCL forms the vesicle membrane, whereas the poly[Phe12-stat-Lys9-stat-(Lys-FA)6] block constitutes the vesicle coronas. Compared to the individual polymer chains, the vesicles showed enhanced antibacterial activities against both Gram-positive and Gram-negative bacteria (16 μg mL–1) due to the locally concentrated antibacterial poly[Phe12-stat-Lys9-stat-(Lys-FA)6] coronas, which may avoid the inducement of antibiotic-resistant bacteria and side effects of multidrug interactions. Furthermore, folic acid is introduced into the vesicle coronas for potential further applications such as cancer-targeted drug delivery. Moreover, the amino groups can be further functionalized when necessary. This low cytotoxic, biocompatible, biodegradable, and antibacterial vesicle (without antibiotic resistance) may benefit patients after tumor surgery because it is highly anti-inflammatory, and it is possible to deliver the anticancer drug to tumor cells simultaneously.
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高影响因子
POLYMER
·
2015
·
IF 3.562
Yanlin Cao,Yuanhong Xu,Jizhen Zhang,Dongjiang Yang,Jingquan Liu
Niobium complex was successfully introduced into atom transfer radical polymerization (ATRP) system as a new kind of recyclable photocatalyst . The niobium complex acted as photocatalyst that could be activated by the photoredox reaction under visible light irradiation and ethyl 2-bromoisobutyrate (EBiB) was used as initiator. Successful ATRP polymerizations of acrylates were realized. The well-defined polymers with controlled molecular weight and narrow polydispersity index (PDI) (M w /M n = 1.16–1.30) could be achieved when the feed ratio of photocatalyst to EBiB was controlled properly. It was also found that the polymerization is highly responsive to light initiation, therefore, the polymerization can be controlled on or off at ease. In addition, the photocatalyst can be recycled and reused to initiate the polymerization for many times without significant compromisation of the initiation efficiency.
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Journal of Physical Chemistry C
·
2015
·
IF 4.772
Juan Yang,Xiaohan Wang,Xiaolei Zhao,Jun Dai,Shengran Mo
In this work, the uniform B2WO6-reduced graphene oxide (BWO–RGO) nanocomposites are prepared via electrostatic self-assembly of positively charged BWO with negatively charged GO sheets and then the composited GO is reduced via the hydrothermal treatment. The close interfacial contact and strong electronic interaction between BWO and RGO are achieved by this facile and efficient self-assembly route. Photocatalytic degradation of pollutant bisphenol A, selective oxidation of benzyl alcohol, removal of heavy metal ion Cr(VI), and selective reduction of 4-nitrophenol are selected as the probe reactions to investigate the photocatalytic activities of as-obtained BWO–RGO nanocomposites. The experimental results demonstrate the photocatalytic redox activities of BWO–RGO composites are predominantly dependent on the energy levels of photoinduced electrons or holes. In particular, the upshift of the valence band and conduction band edge of catalysts induced by the electronic interaction between BWO and RGO has an inconsistent influence on the photocatalytic reduction and oxidation reactions, respectively. As a result, the photocatalytic activity of reduction reactions is significantly enhanced, owing to the synergetic effect of the upshift of conduction band edge and the improved separation of photogenerated electrons/holes, while the oxidation ability of BWO–RGO nanocomposite is improved to a slight extent compared with bare BWO. The energy levels of photogenerated carriers should be the origins accounting for the different enhancement of photocatalytic activities for the different reactions. According to the discussion, one important conclusion can be drawn, that is, the results should be analyzed on the basis of specific reactions when discussing the effect of graphene or RGO on the photocatalytic properties of semiconductor particles.
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Materials Science & Engineering C-Materials for Biological Applications
·
2014
·
IF 2.736
Hui-Kang Yang,Li-Ming Zhang
For the development of biomimetic carriers for stimuli-sensitive delivery of anticancer drugs, a novel amphiphilic glycopolypeptide conjugate containing the disulfide bond was prepared for the first time by the ring-opening polymerization of benzyl glutamate N -carboxy anhydride in the presence of (propargyl carbamate)ethyl dithio ethylamine and then click conjugation with α-azido dextran. Its structure was characterized by Fourier-transform infrared spectroscopy and nuclear magnetic resonance analyses. Owing to its amphiphilic nature, such a conjugate could self assemble into nanosize micelles in aqueous medium, as confirmed by fluorometry, transmission electron microscopy and dynamic light scattering. For the resultant micelles, it was found to encapsulate poorly water-soluble anticancer drug (methotrexate, MTX) with the loading efficiency of 45.2%. By the in vitro drug release tests, the release rate of encapsulated MTX was observed to be accelerated significantly in the presence of 10 mM 1,4-dithio-DL-threitol (DTT), analogous to the intracellular redox potential.
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高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2015
·
IF 2.037
Hui Wang,Qinbo Wang,Zhenhua Xiong,Chuxiong Chen,Binwei Shen
By using the synthetic method, the solubilities of benzoic acid in binary methylbenzene + benzyl alcohol solvent mixtures at (301.05 to 355.65) K and in binary methylbenzene + benzaldehyde solvent mixtures at (301.05 to 354.45) K were determined at atmospheric pressure. The studied mass fractions of benzyl alcohol and benzaldehyde in the corresponding binary solvent mixtures range from 0.0 to 1.0. It was found that the measured solubilities increase with the increase of temperature at constant solvent composition. For the ternary system benzoic acid + methylbenzene + benzyl alcohol, the results show that the binary methylbenzene + benzyl alcohol solvent mixture with the mass fraction of benzyl alcohol at 0.80 has the best dissolving capacity for benzoic acid at constant temperature. However, for the ternary system benzoic acid + methylbenzene + benzaldehyde, the results show that the binary methylbenzene + benzaldehyde solvent mixture with the mass fraction of benzaldehyde of 0.20 has the best dissolving capacity for benzoic acid at constant temperature. The experimental data were correlated by both the nonrandom two-liquid (NRTL) and the Apelblat equations, and the correlated solubilities agree satisfactorily with the experimental observations. By coupling the Apelblat equation with the Clark and Glew equation, the thermodynamic functions for the two studied solid–liquid equilibrium systems, including dissolution enthalpy, entropy, Gibbs energy, and isobaric heat capacity, were calculated and discussed.
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FOOD CHEMISTRY
·
2013
·
IF 3.334
Yunzi Feng,Yu Cai,Guowan Su,Haifeng Zhao,Chenxia Wang,Mouming Zhao
Two types of Chinese soy sauce , high-salt liquid-state fermentation soy sauce (HLFSS) and low-salt solid-state fermentation soy sauce (LSFSS), were used to investigate their differences in aroma profile by headspace solid-phase microextraction (HS-SPME) and gas chromatography-olfactometry/mass spectrometry (GC-O/MS). Results from descriptive sensory analysis showed that the alcoholic, cooked potato-like and caramel-like attributes were significantly higher in HLFSS, while LSFSS exhibited significantly higher sour and burnt attributes. In addition, aroma extract dilution analysis (AEDA) revealed 37 and 33 odour-active regions for HLFSS and LSFSS, respectively. Ethanol, 3-methyl-1-butanol, phenylacetaldehyde , 4-ethyl-2-methoxyphenol, 2-methoxy-4-vinylphenol and 3-(methylthio)propanal detected in HLFSS showed the highest flavour dilution (FD) factors, while 3-methylbutanal, phenylacetaldehyde and ethyl propanoate possessed the highest FD factors in LSFSS. Therefore, the traditional Chinese soy sauce HLFSS contained more complex volatiles and exhibited a richer aromatic profile compared with LSFSS.
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高影响因子
Nano Energy
·
2013
·
IF 0
Yan-Qing Zhang,De-Kun Ma,Yan-Ge Zhang,Wei Chen,Shao-Ming Huang
N-doped nanostructured carbon materials have attracted much attention because the doping can induce new unique physical and chemical properties of carbon. In this study, we report, for the first time, that N-doped carbon quantum dots (NCQDs) can combine with rutile TiO 2 and form NCQDs/TiO 2 hierarchical microspheres assembled by nanorods with enhanced photocatalytic activities under visible light irradiation. As a result, the pseudo-first-order reaction constant for the degradation of rhodamine B (RhB) on NCQDs/TiO 2 (0.11 min −1 ) is 215.7, 7.3 and 1.3 times much larger than that of NCQDs (0.00051 min −1 ), TiO 2 (0.015 min −1 ), and CQDs/TiO 2 (0.086 min −1 ), respectively. The functions of NCQDs were discussed and a new synergistic photosensitized mechanism was proposed for the degradation of RhB on the as-synthesized NCQDs/TiO 2 nanocomposites based on the experimental results. NCQDs were also applied as metal-free sensitizers in dye-sensitized solar cells (DSSCs) for the first time. A preliminary study shows that under one sun illumination (AM 1.5), the open circuit voltage and fill factor values reach 0.46 V and 43%, respectively, achieving a power conversion efficiency of 0.13% in the proof-of-concept TiO 2 -based DSSCs device. The performance of NCQDs sensitized solar cells surpasses that of N-free counterpart as well. N-doping lowered the work function of CQDs, which was responsible for enhanced photocatalytic activity of NCQDs/TiO 2 and better NCQDs sensitized TiO 2 -based solar cell performance.
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