MACROMOLECULAR RAPID COMMUNICATIONS
·
2017
·Vol. 38
·期 5
·1600745
·
IF 4.265
Wei Yuan,Weiwen Chi,Ruimin Liu,Hongkun Li,Yongfang Li,Ben Zhong Tang
Two soluble poly(phenyltriazolylcarboxylate)s (PPTCs) with high molecular weights ( M w up to 26 800) are synthesized by the metal-free 1,3-dipolar polycycloadditions of 4,4′-isopropylidenediphenyl diphenylpropiolate ( 1 ) and tetraphenylethene-containing diazides ( 2 ) in dimethylformamide at 150 °C for 12 h in high yields (up to 93%). The resultant polymers are soluble in common organic solvents and are thermally stable with 5% weight loss temperatures higher than 375 °C. The PPTCs are nonemissive in solutions, but become highly luminescent upon aggregation, showing a phenomenon of aggregation-induced emission. Their aggregates can be used as fluorescent chemosensors for high-sensitivity detection of explosives.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2016
·Vol. 28
·期 1
·949-957
·
IF 1.798
Qiu Qingchao,Yang Weihua,Zhan Yangfan,Wang Hao
The development of non-noble metal catalysts is of great interest due to their significant potential application in both fuel cell system and metal-air batteries, particularly when considering long term commercial deployment. Fe/N/C is a promising non-Pt electrocatalyst for the oxygen reduction reaction (ORR), but its catalytic activity is considerably inferior to that of Pt in acidic medium. In this paper, an improved Fe/N/S/C catalyst (denoted as Fe–N–S/C) is presented. Nitrogen-sulfur-iron-doped porous carbon material is synthesized by the pyrolysis of dicyandiamide, a kind of abundant and inexpensive compound, with thiourea as additional sulfur source in argon atmosphere. The Fe–N–S/C shows excellent performance for the ORR with the onset and half-wave potential at 0.89 and 0.78 V (vs.RHE) in 0.1 M H 2 SO 4 solution, respectively, which are significantly higher compared to those of the catalysts derived from only dicyandiamide (0.85 and 0.75 V). Our results indicate that as compared to the commercial 20 % Pt/C catalyst, the synthesized catalyst exhibits not only higher current density and long-term durability but also higher tolerance to methanol poisoning. More importantly, the synthetic method is simple and inexpensive.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2013
·
IF 4.093
Kunzhi Shen,Jinhui Pang,Sinan Feng,Yang Wang,Zhenhua Jiang
The poly(aryl ether ketone)s containing two quaternary ammonium groups on pendant phenyls are obtained via a bromination reaction following a quaternization process. Poly(aryl ether ketone)s with two methyl groups on pendant phenyls, which can be converted to bromomethyl groups by a radical reaction, are synthesized. Cationic quaternized poly(aryl ether ketone)s result from conversion of the bromomethyl groups to ionic moieties by quaternization with trimethylamine in the shape of clear, creasable films. The highest conductivity 0.0307 S cm −1 is achieved by the QMPAEK-75 membrane with ion exchange capacity of 1.35 meq. g −1 at 80 °C. Meanwhile, these anion exchange membranes also have good mechanical properties , very low methanol permeability, high thermal stability, chemical stability and dimensional stability, which play important roles in the preparation of direct methanol fuel cells.
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2012
·
IF 2.105
Hongwei Wei,Hechun Jiang,Zhen Zheng,Quanqin Zhao,Qingyin Wu,Jinhua Zhan
A series of one-dimensional Cd x Zn (1− x ) S semiconductor alloys were prepared via a hydrothermal method with the assistance of ethylenediamine at 180 °C for 12 h. The products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, nitrogen adsorption/desorption and Fourier transform infrared techniques. With the value of x increased, the band gap of Cd x Zn (1− x ) S semiconductor alloys gradually decreased indicating that catalysts were exchanged to visible-light response. Photocatalytic reduction results showed that Cd 0.73 Zn 0.27 S exhibited the highest photocatalytic activity toward photo production of aniline via nitrobenzene reduction under visible irradiation respectively. The reaction mechanism was also discussed.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2015
·Vol. 3
·期 39
·10114-10120
·
IF 4.696
Zhenyang Liu,Aiwei Tang,Miao Wang,Chunhe Yang,Feng Teng
A simple heating-up colloidal approach has been developed to synthesize quaternary Cu–In–Zn–S (CIZS) nanocystals with different emission colors, which can be tuned by varying the Cu : In : Zn precursor ratios. The as-obtained products have a quasi-triangular shape with a small size distribution, and their crystal phase can be varied from cubic zinc-blende to hexagonal wurtzite structure with an increase of Cu stoichiometry. The inductively coupled plasma optical emission spectrometry (ICP-OES) results reveal that the as-obtained CIZS nanocrystals are Cu-deficient, and the Cu-vacancies have a significant effect on their optical properties. Moreover, the photoluminescence (PL) spectra of the CIZS nanocrystals recorded at different growth periods indicate that the partial cation exchange of Cu+ and In3+ with Zn2+ takes charge of the growth process. After coating a ZnS shell over the CIZS nanocrystals, the PL quantum yield (PLQY) is improved greatly and a blue-shift of the PL peak is observed as compared to that of plain CIZS nanocrystals. More interestingly, the highly luminescent CIZS/ZnS core/shell nanocrystals with different colors have been incorporated into poly(dimethylsiloxane) (PDMS) to be fabricated on an engraved “BJTU” glass substrate, and the as-obtained PDMS membranes exhibit a bright emission under UV light, which also show good stability when they are bent arbitrarily or immersed in water. This heating-up method has also been extended to the preparation of five-component Cu–Ag–In–Zn–S and Cu–Mn–In–Zn–S nanocrystals, which possess a cubic zinc-blende crystal structure and have bright luminescence. Our work may shed light on the synthesis of multi-component semiconductor nanocrystals.
✓ 已验证
产品关联
DOI
高影响因子
ENZYME AND MICROBIAL TECHNOLOGY
·
2014
·
IF 2.966
Chuan-Yang Shang,Wei-Xun Li,Rui-Feng Zhang
ZnO nanowires were successfully introduced into a macroporous SiO 2 by in situ hydrothermal growth in 3D pores. The obtained composites were characterized by SEM and XRD, and used as supports to immobilize Candida antarctica lipase B (CALB) through adsorption. The high specific surface area (233 m 2 /g) and strong electrostatic interaction resulted that the average loading amount of the composite supports (196.8 mg/g) was 3–4 times of that of macroporous SiO 2 and approximate to that of a silica-based mesoporous material. Both adsorption capacity and the activity of the CALB immobilized on the composite supports almost kept unchanged as the samples were soaked in buffer solution for 48 h. The chiral resolution of 2-octanol was catalyzed by immobilized CALB. A maximum molar conversion of 49.1% was achieved with 99% enantiomeric excess of ( R )-2-octanol acetate under the optimal condition: a reaction using 1.0 mol/L ( R , S )-2-octanol, 2.0 mol/L vinyl acetate and 4.0 wt.% water content at 60 °C for 8 h. After fifteen recycles the immobilized lipase could retain 96.9% of relative activity and 93.8% of relative enantioselectivity .
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Energies
·
2013
·Vol. 6
·期 7
·3466-3480
·
IF 1.844
Haibo Tan,Shengping Wang,Du Tao,Zhigao Yang
A novel technique to prepare carbon/sulfur composites as cathode materials for Li/S batteries is proposed, which we call the ‘solution evaporation concentration crystallization’ method. Three composites with different S loadings were prepared, subject to two different solvent evaporation rates from acetylene black (AB)/sulfur in carbon disulfide solutions. X-ray diffraction, environmental scanning electron microscopy, transmission electron microscopy, and Brunauer-Emmett-Teller measurements all show that the porous AB structure is well-filled with S. Composites prepared at a lower solvent evaporation rate with 50 wt % S content, had good electrochemical properties, with 1609.67 mAh g−1in the initial cycle and 1115.69 mAh g−1after 100 cycles. Composites with better dispersibility at a low solvent evaporation rate can effectively prevent polysulfide from dissolving in the electrolyte, and serve to stabilize the structure of the S cathode during the charge-discharge process.Keywords:sulfur/carbon composites;solution evaporation concentration crystallization method;lithium sulfur batteries
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2014
·
IF 5.9
Wangen Zhao,Gang Wang,Qingwen Tian,Yanchun Yang,Lijian Huang,Daocheng Pan
Cu2ZnSn(S,Se)4 semiconductor is a promising absorber layer material in thin film solar cells due to its own virtues. In this work, high quality Cu2ZnSn(S,Se)4 thin films have been successfully fabricated by an ethanol-based sol–gel approach. Different from those conventional sol–gel approaches, SnS2 was used as the tin source to replace the most commonly used SnCl2 in order to avoid the possible chlorine contamination. In addition, sodium was found to improve the short-circuit current and fill factor rather than the open-circuit voltage due to the decrease of the thickness of small-grained layer. The selenized Cu2ZnSn(S,Se)4 thin films showed large densely packed grains and smooth surface morphology, and a power conversion efficiency of 6.52% has been realized for Cu2ZnSn(S,Se)4 thin film solar cell without antireflective coating.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Scientific Reports
·
2015
·Vol. 5
·期 1
·1-17
·
IF 5.578
Li Jian-Long,Zhao Wei,Zhou Chen,Zhang Ya-Xuan,Li Hong-Mei,Tang Ya-Ling,Liang Xin-Hua,Chen Tao,Tang Ya-Jie
Herein is a first effort to systematically study the significance of carbon-sulfur (C-S) and carbon-amine (C-NH) bonds on the antitumor proliferation activity of podophyllum derivatives and their precise mechanism of apoptosis. Compared with the derivative modified by a C-NH bond, the derivative modified by a C-S bond exhibited superior antitumor activity, the inhibition activity of target proteins tubulin or Topo II, cell cycle arrest and apoptosis induction. Antitumor mechanistic studies showed that the death receptor and the mitochondrial apoptotic pathways were simultaneously activated by the C-S bond modified aromatic heterocyclic podophyllum derivatives with a higher cellular uptake percentage of 60–90% and induction of a higher level of reactive oxygen species (ROS). Only the mitochondrial apoptotic pathway was activated by the C-NH bond modified aromatic heterocyclic podophyllum derivatives, with a lower cellular uptake percentage of 40–50%. This study provided insight into effects of the C-S and C-NH bond modification on the improvement of the antitumor activity of Podophyllum derivatives.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
HIGH PERFORMANCE POLYMERS
·
2014
·
IF 1.09
Yuxuan Zhang,Qing Zhang,Songhao Pei,Yongpeng Wang,Haibo Zhang,Zhenhua Jiang
To improve the stability of photoinduced birefringence, a series of azobenzene-functionalized poly(ether sulfone)s (azo-PES) with high glass transition temperature (Tg) were successfully synthesized via Ullmann coupling between PES with bromine side groups and azo compound 4-((4-methoxyphenyl)diazenyl)phenol. Their chemical structures and properties were characterized by means of ultraviolet–visible and proton nuclear magnetic resonance spectroscopies. The results of differential scanning calorimetry and thermogravimetric analysis suggested that the polymers had high Tgs and good thermal stability. Upon irradiation with a 532 nm neodymium-doped yttrium aluminium garnet (Nd:YAG) laser beam, these azo polymers presented large photoinduced birefringence with a remnant value up to 94%, indicating good stability of the photoinduced orientation. Furthermore, multiple writing/erasing experiments indicate that the azo polymers have potential applications in reversible optical storage.
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2015
·Vol. 33
·期 11
·1491-1502
·
IF 1.835
Fang Li-feng,Wang Na-chuan,Zhou Ming-yong,Zhu Bao-ku,Zhu Li-ping,John Angelin Ebanezar
To functionalize poly(vinyl chloride) (PVC) for various applications, monomers containing tertiary amine group are incorporated into PVC via atom transfer radical polymerization (ATRP) initiated by the labile chlorines in their backbones. The kinetics of synthesis was carefully investigated, and it is proven that the grafting polymerization process can be effectively controlled by regulating the reaction time. The membranes are fabricated using PVC and copolymers by non-solvent induced phase separation (NIPS) process. The hydrophilicity and pore structure of copolymer membranes were enhanced as well, these membranes are endowed with positive charge. When PDMA% ( i.e. , the PDMA weight percentage in copolymer) is 31.1%, the flux and Victoria blue B rejection are 26.0 L·m -2 ·h -1 (0.5 MPa) and 91.2%, respectively. Thus, the newly synthesized polymer is proven to be a promising material for dye separation with positive charges.
✓ 已验证
产品关联
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2015
·
IF 1.286
Qiuxiang Wu,Zhizhou Yang,Jinshui Yao,Donghong Yu
Five new optically active poly(amide–imide)s (PAIs) (PAI3a–PAI3e) were synthesized through the direct polycondensation reaction between chiral N,N′-(pyromellitoyl)-bis-l-amino acids and 4,4′-diaminodiphenyl ether. The resulted polymers were fully characterized by means of Fourier transform infrared (FTIR) and proton nuclear magnetic resonance spectroscopy, elemental analysis, inherent viscosity measurement, solubility tests, specific rotation, and thermogravimetric analysis (TGA). The biodegradation studies of the PAIs were performed in soil and in phosphate buffer solution. The surface morphology and hydrophobicity of the biodegraded PAI films were investigated. FTIR spectra showed structural changes on PAI powders being treated in phosphate buffer solution. The TGA data showed that the thermal stability of PAI powders decreased with the degradation time. The collected degradation products were soluble in water and had absorption in ultraviolet and visible light region. Possible biodegradation mechanism of amino acid-based PAIs was explored.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）