JOURNAL OF APPLIED POLYMER SCIENCE
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2018
·Vol. 135
·期 31
·46532
·
IF 1.901
Xinxiu Wu,Jinhui Li,Gang Li,Lei Ling,Guoping Zhang,Rong Sun,Ching-Ping Wong
Polydimethylsiloxane (PDMS) is one of the most widely employed silicon-based polymers for its high flexibility, low usage temperature, excellent water resistance, outstanding electrical insulting property, and physiological inert, etc. However, the covalent-bonded Si O bonds are unable to heal automatically when damaged, which would result in the failure of the materials and devices. Disulfide bond based polymers show high healing efficiency at moderate temperature and have been investigated intensively. Herein, we report a PDMS-based polyurethane self-healing polymer (PDMS-PU) modified with disulfide bonds, which exhibited a reinforced thermal stability, excellent stretchability, and satisfactory self-healing ability. The effect of different ratio of PDMS and disulfide bond contents on the elastomer properties was investigated. With the increase of PDMS content, the decomposition temperature of the PDMS-PU-3 (332 °C) elastomer with highest content of PDMS was increased by 34 °C compared to PDMS-PU-1 (298 °C) with lowest content of PDMS and exhibited a largest elongation at break of 1204%. PDMS-PU-1 with highest content of disulfide bond possessed a highest healing efficiency of 97%. The results indicated the PDMS-PU elastomers can be used as self-healing flexible substrate for flexible electronics. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 46532.
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Polymers
·
2018
·Vol. 10
·期 4
·441
·
IF 2.935
Weiqiu Wen,Jianwei Guo,Xi Zhao,Xiong Li,Hongmei Yang,Jem-Kun Chen
Considering the poor compatibility and water-resistance of sulfonate flame retardants for polycarbonate (PC), an efficient S/N-based flame retardant named 1,3,5,7-tetrakis(phenyl-4-sulfonyl-melamine)adamantane (ASN) has been developed. Fire properties studies of PC/ASN blends indicate that the addition of 0.10 wt % ASN imparts a V-0 rating and a limited oxygen index (LOI) value of 30.1% to PC specimens, and ASN can suppress the heat and toxic gas release of PC composites. Additionally, PC/ASN blends are believed to be exceptional materials for outdoor PC applications due to their superior water-resistance properties. Moreover, mechanical properties were further systematically investigated, and the correlative results indicate that the tensile strength and rigidity of specimens are improved with the addition of ASN.Keywords:flame retardant;adamantane;polycarbonate;fire properties;water-resistance
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CHINESE JOURNAL OF CATALYSIS
·
2018
·
IF 3.525
Zhou Ren,Yuan Lyu,Siquan Feng,Xiangen Song,Yunjie Ding
Highly active Ir-La-S/AC catalyst was successfully prepared by co-impregnation of an activated carbon (AC) carrier with a sulfuric acid solution of Ir and La species and compared with a traditionally prepared Ir-La/AC catalyst. High angle annular dark-field-scanning transmission electron microscopy (HAADF-STEM) measurement results show that most of the Ir species on Ir-La-S/AC exist as single atomic sites, while those on Ir-La/AC exist as nanoparticles with an average diameter of 1.5 nm. Evaluation of Ir-La-S/AC as a catalyst for heterogeneous carbonylation of methanol to acetyl gave a maximum TOF (turn-over-frequency) of 2760 h −1 , which was distinctly higher than that achieved by the Ir-La/AC catalyst (approximately 1000 h −1 ). Temperature-programmed desorption of ammonia (NH 3 -TPD) result shows that the addition of sulfuric acid during the preparation procedure results in significantly more acidic sites on Ir-La-S/AC than those on Ir-La/AC, which plays a key role in the enhancement of CO insertion as the rate-determining step. Temperature-programmed reduction (TPR) and in situ X-ray photoelectron spectroscopy reveal that Ir species are more reducible, and that more Ir + might be formed by activation of Ir-La-S/AC than those on the Ir-La/AC catalyst, which is thought to be beneficial for reductive elimination of AcI from Ir 3+ species as an essential step for CH 3 I regeneration and acetyl formation.
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APPLIED CATALYSIS B-ENVIRONMENTAL
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2018
·
IF 11.698
Haodan Xu,Da Wang,Jun Ma,Tao Zhang,Xiaohui Lu,Zhiqiang Chen
In this paper, for the first time the spinel sulfide carrollite (CuCo 2 S 4 ) was applied to activate peroxymonosulfate (PMS) for the abatement of an endocrine disrupting compound (EDC) bisphenol S (BPS) in water. The hydrothermally synthesized CuCo 2 S 4 outperformed conventional cobalt and copper oxides/sulfides in both catalytic activity and stability (i.e. metal leaching) in this oxidation process. The spinel sulfide was most active under neutral pH conditions, which is preferred for water/wastewater treatment. Sulfate radicals (SO 4 − ) which was proved to be the prominent oxidant species in this oxidation process, attacked on BPS producing multiple hydroxylated degradation intermediates. Cu(II)/Cu(I) and Co(III)/Co(II) synergetic surface redox couples are found responsible for the catalytic activation of PMS producing SO 4 − ; furthermore, the thermodynamically favorable reaction between surface Cu(I) and surface Co(III) guarantees the electron transfer between the surface metal sites. As confirmed by turnover frequency calculation, CuCo 2 S 4 has higher catalytic effect per surface cobalt atom than the counterpart oxides for PMS activation, probably due to the lower electronegativity of S 2− than O 2− . CuCo 2 S 4 could be a potentially useful catalyst for water/wastewater treatment.
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MICROCHIMICA ACTA
·
2018
·Vol. 185
·期 12
·1-9
·
IF 5.705
Wang Yongping,Yue Qiaoli,Tao Lixia,Zhang Cong,Li Chen-Zhong
N/S/P-codoped carbon dots (CDs) are shown to be a viable fluorescent probe in a turn-off-on fluorometric assay for hydroquinone (HQ). The preparation of CDs was carried out using a one-step hydrothermal reaction starting with glyoxal and isocarbophos. The method is based on the formation of ground state complexes between CD and Fe(III) which leads to quenching of blue fluorescence (with excitation/emission peaks at 363/448 nm). On addition of HQ, it will be oxidized by Fe(III) upon which fluorescence recovers. This turn-off-on system can be utilized to quantify HQ. A linear relationship exists between fluorescence recovery and HQ concentration in range between 0.56 and 375 μM. The limit of detection is 0.16 μM. The assay was successfully applied to the determination of HQ in spiked water samples and developer samples.
Fluorometric determination of hydroquinone (with good selectivity over catechol and resorcinol) by using blue-emitting N/S/P-codoped carbon dots and the quenching effect of Fe(III).
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ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Lijian Huang,Song Wei,Daocheng Pan
Large-grained Cu2ZnSn(S,Se)4 (CZTSSe) absorber layers are highly desirable for high-performance CZTSSe thin film solar cells. However, solution-deposited CZTSSe thin films usually consist of a large-grained top layer and a smaller-grained bottom layer. In this work, we adopt a phase-separation strategy to promote the crystal growth of the CZTSSe thin film. By choosing ZnCl2, SnCl2, CuCl (instead of CuCl2), and thiourea as the starting materials, a Cu2S/SnS/ZnS hybrid precursor thin film can be prepared, the composition of which has been testified by X-ray diffraction, X-ray photoelectron spectroscopy, Raman, and scanning electron microscopy-energy-dispersive spectrometry characterization. Owing to the volume expansion caused by Se incorporation and the high migration abilities of Cu(I) and Sn(II) ions during selenization, large-grained and compact CZTSSe films with a thickness up to 5 μm can be obtained. The corresponding thin film solar cell devices have achieved active power conversion efficiencies above 10% (8.78% for total area), much higher than those of CuCl2-based CZTSSe devices in our lab.
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Journal of Materials Chemistry C
·
2015
·Vol. 3
·期 34
·8844-8851
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IF 4.696
Sheng Cao,Jialong Zhao,Weiyou Yang,Chengming Li,Jinju Zheng
In the present work, we reported the synthesis of Mn2+-doped Zn–In–S quantum dots (QDs) with high optical performance in a controlled manner. The effects of the temperature, the introduced ODE-S amount and Zn/In ratios in the raw materials, as well as the Mn2+ doping concentrations on the photoluminescence (PL) properties of Mn2+-doped Zn–In–S QDs were investigated systematically. The resultant QDs exhibit tunable bandgaps ranging from 2.9 to 3.7 eV, well-resolved Mn2+ d–d emission with a PL quantum yield (QY) of 56% and a surprisingly long excited state lifetime up to ∼4.2 ms, suggesting their excellent PL properties. Meanwhile, the initial high PL QY of the obtained Mn2+-doped Zn–In–S QDs in organic solvents could be preserved very well once they were transferred into aqueous media via ligand exchange. Furthermore, the as-synthesized QDs exhibit excellent thermal stability up to 200 °C in a crude solution.
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Polymer Chemistry
·
2013
·Vol. 4
·期 10
·3020-3027
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IF 5.231
Yangyi Sun,Yuyong Yin,Min Chen,Shuxue Zhou,Limin Wu
This paper presents a one-step procedure for the facile synthesis of monodisperse raspberry-like polymer colloidal particles by soap-free emulsion polymerization of styrene (S), acrylic acid (AA), and 3-(trimethoxysilyl)propyl methacrylate (MPS). In this method, when S, AA, and MPS are mixed with water and stirred at a certain temperature, raspberry-like P(S–MPS–AA) colloidal particles with uniform shapes and sizes could be obtained in a reliable manner. Both the core particles and the smaller corona particles of core surfaces were formed in situ. A mechanism of formation based on the second nucleation induced by MPS-enriched segments on the core surfaces is proposed.
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JOURNAL OF SOLID STATE ELECTROCHEMISTRY
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2012
·Vol. 17
·期 4
·961-968
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IF 2.131
Yue Lu,Zhong Haoxiang,Tang Daoping,Zhang Lingzhi
A novel porous Si/S-doped carbon composite was prepared by a magnesiothermic reaction of mesoporous SiO 2 , subsequently coating with a sulfur-containing polymer-poly(3,4-ethylene dioxythiophene), and a post-carbonization process. The as-prepared Si composite was homogeneously coated with disordered S-doped carbon with 2.6 wt.% S in the composite and retained a high surface area of 58.8 m 2 g −1 . The Si/S-doped carbon composite exhibited superior electrochemical performance and long cycle life as an anode material in lithium ion cells, showing a stable reversible capacity of 450 mAh g −1 even at a high current rate of 6,000 mA g −1 .
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TRANSACTIONS OF TIANJIN UNIVERSITY
·
2012
·Vol. 18
·期 5
·315-319
·
IF 0
Feng Yakai,Chen Chengbin,Zhang Li,Tian Hong,Yuan Wenjie
A series of novel copolymers were successfully synthesized by ring-opening polymerization (ROP) of 3(S)-methyl-morpholine-2,5-dione (MMD) and 5-methyl-5-benzyloxycarbonyl-1,3-dioxan-2-one (MBC) using stannous octoate as catalyst. The copolymers were characterized by means of 1H-NMR and FT-IR spectroscopy. Gel permeation chromatography (GPC) test shows that the average-number relative molecular mass and average-weight relative molecular mass slightly increase with the increase of MBC content in feed. The results of differential scanning calorimetry (DSC) demonstrate that the glass transition temperature of copolymers increases with the increase of MBC content in copolymers. The copolymers of MMD and MBC are amorphous copolymers, as indicated by DSC results, while the homopolymer of MMD is semicrystalline.
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MONATSHEFTE FUR CHEMIE
·
2014
·Vol. 145
·期 12
·1925-1931
·
IF 1.347
Tu Xingzhao,Zhou Lihong,Li Zhijie,Lei Ning,Zeng Qingle
Abstract The carbon-heteroatom bond formation is an important research field. Transition-metal-free synthesis of medicinally important heterocycles avoids products of transition metal contamination, and thus it is an environmentally friendly and cost-saving process. A transition-metal-free domino C-S/C-N formation for the synthesis of imidazobenzothiazines from 2-mercaptobenzimidazoles and 2-halobenzyl bromides is developed. The desired products were obtained in good to excellent yields. The mechanism of domino nucleophilic substitution (S N 2) and nucleophilic aromatic substitution (S N Ar) is proposed. Graphical abstract
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Nanoscale
·
2015
·Vol. 7
·期 28
·11956-11961
·
IF 7.394
Wenxiu Yang,Xiaoyu Yue,Xiangjian Liu,Junfeng Zhai,Jianbo Jia
A highly efficient N, S co-doped porous carbon ORR catalyst was simply designed in our report from ordered mesoporous carbon (OMC) and trace ionic liquids (ILs). The microstructure OMC was chosen as the template for improving the specific area, confining the ILs in the mesopores, and promoting the formation of the planar N and S doping. The resulting IL/OMC (IOMC) nanostructure exhibits comparable ORR activity and better stability than the commercial Pt/C catalyst in 0.10 M KOH solution, which makes it one of the best-performing metal-free carbon ORR catalysts. We deduced that the excellent ORR activity is attributed to the synergistic effect of N, S, and the ordered mesoporous structure. Interestingly, the ORR activity can be further boosted in both basic and acidic solutions after Fe doping into the IOMC nanostructures which clearly emphasizes that transition metal Fe is important for the construction of ORR active functional sites especially in acidic solution.
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危险品化学品经营许可证（带存储）