JOURNAL OF POLYMER RESEARCH
·
2015
·Vol. 22
·期 2
·1-8
·
IF 1.92
He Zhicai,Zhong Mingqiang,Yang Jintao
Aiming to prepare polystyrene microcellular foam with improved foam morphology and high thermal stability, ionic liquids which have been well demonstrated to possess high carbon dioxide (CO 2 ) absorption capacity were introduced into polystyrene by copolymerization of styrene and polymerizable ionic liquids, i.e., vinylbenzyl trimethyl ammonium fluoroborate ([VBTMA][BF 4 ]) and vinylbenzyl trimethyl ammonium hexafluorophosphate ([VBTMA][PF 6 ]), Abbr. ILs). These copolymers showed higher glass transition temperature (T g ) and high supercritical carbon dioxide (scCO 2 ) solubility, based on which foams with smaller cell size, higher cell density, and higher thermal stability were prepared by the microcellular foaming using scCO 2 as blowing agent. The morphology of the resultant foams highly depended on the foaming temperature, ionic liquid type and content. Compared to [VBTMA][BF 4 ]-St foam, [VBTMA][PF 6 ]-St have higher CO 2 absorption and glass-transition temperature, making it exhibit superior cell morphology. This work demonstrates that the introduction of ionic liquids can benefit the morphology control and thermal stability of polymeric foams and hopefully provides a promising method for the design and preparation of polymeric foams with high performance.
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Nature Communications
·
2023
·Vol. 14
·期 1
·1-9
·
IF 16.6
Feng Sihua,Duan Hengli,Tan Hao,Hu Fengchun,Liu Chaocheng,Wang Yao,Li Zhi,Cai Liang,Cao Yuyang,Wang Chao,Qi Zeming,Song Li,Liu Xuguang,Sun Zhihu,Yan Wensheng
The development of two-dimensional (2D) magnetic semiconductors with room-temperature ferromagnetism is a significant challenge in materials science and is important for the development of next-generation spintronic devices. Herein, we demonstrate that a 2D semiconducting antiferromagnetic Cu-MOF can be endowed with intrinsic room-temperature ferromagnetic coupling using a ligand cleavage strategy to regulate the inner magnetic interaction within the Cu dimers. Using the element-selective X-ray magnetic circular dichroism (XMCD) technique, we provide unambiguous evidence for intrinsic ferromagnetism. Exhaustive structural characterizations confirm that the change of magnetic coupling is caused by the increased distance between Cu atoms within a Cu dimer. Theoretical calculations reveal that the ferromagnetic coupling is enhanced with the increased Cu-Cu distance, which depresses the hybridization between 3 d orbitals of nearest Cu atoms. Our work provides an effective avenue to design and fabricate MOF-based semiconducting room-temperature ferromagnetic materials and promotes their practical applications in next-generation spintronic devices.
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COLLOID AND POLYMER SCIENCE
·
2009
·Vol. 288
·期 2
·173-179
·
IF 1.736
Chen Jiucun,Wang Haodong,Luo Wenqian,Xiang Jiming,Zhang Lihui,Sun Baoben
In this work, by a combination of controlled ring-opening polymerization (CROP) and click chemistry, we report a facile and useful method to synthesize linear poly(ε-caprolactone)@attapulgite nanocomposites with well-defined structures. For this, first, the chlorine-terminated attapulgite was prepared by the self-assembly of 3-chloropropyltrimethoxysilane from the surfaces of attapulgite. And then, the terminal chlorines of modified attapulgite were substituted with azido groups. As the second step, linear propargyl-terminated poly(ε-caprolactone) (PCLs) with different molecular weights were synthesized by the CROP of ε -CL monomer in toluene with stannous octoate as a catalyst and propargyl alcohol as an initiator. The structural characteristics of the obtained linear PCLs have been determined by 1 H NMR and gel permeation chromatography analysis. Finally, the azido-terminated attapulgite was reacted with propargyl-terminated PCLs via the click reaction.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2017
·Vol. 28
·期 13
·9464-9470
·
IF 2.019
Xing Yangyang,Zhu Yingchun,Chang Chengkang,Wang Yunli,Wang Yang
Eu 2+ -doped β-Sialon phosphors with a composition of Eu
x
Si 5 Al 1− x
O z+ x
N 8−z− x
( x = 0.05, 0.06, 0.07) were synthesized in a new synthetic route using novel raw materials, such as nano-silicon dioxide (SiO 2 ), nano-carbon (C), and aluminum (Al). This is different from the prevailing method using Si 3 N 4 , AlN, and Al 2 O 3 to obtain β-Sialon phosphors. Compared with the conventional method, lower cost raw materials, simpler pretreatment and a relatively shorter reaction time are achieved. The phosphors show a high purity. All the phosphors exhibit green emission under ultra violet (UV) radiation. A broad band of excitation spectra implies the promising application in UV ray based green light-emitting diode (LED). Chromaticity coordinates of the β-Sialon: Eu 2+ phosphors demonstrate that it is accessible to obtain different green emissions from single phase of Eu 2+ -doped β-Sialon through adjusting Eu 2 O 3 concentration. Furthermore, the Eu
x
Si 5 Al 1− x
O 1 + x
N 7 − x
( x = 0.05) shows a better thermal stability than the commercial green-emitting silicate phosphor. These results indicate a promising prospect for this efficient and economic route in preparing β-Sialon: Eu 2+ phosphors, and the phosphors are a highly promising candidate for LED applications.
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JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 53
·期 19
·13924-13935
·
IF 2.993
Liu Huihui,Xiang Miaomiao,Shao Xiang
The interface of graphene (G) and oxide can significantly influence the properties and/or applications of the binary system. However, it is usually beyond controllability during the conventional physical intermixing and/or solvothermal preparations. In this article, by directly growing nanocrystalline graphene films on the ZnO nanocrystals through a medium-temperature chemical vapor deposition method utilizing C 2 H 2 as the carbon source, we successfully achieved a G/ZnO binary structure with a uniform and contamination-free G/oxide interface. The fabricated G/ZnO powders not only demonstrated a clear charge transfer between graphene and ZnO that leads to photoluminescence quenching, but also manifested an enhanced activity in the photocatalytic degradation of methylene blue when the graphene thickness is optimized. This work has demonstrated the essential significance of the interface control for the functionality of the graphene/semiconductor binary systems.
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CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2022
·Vol. 38
·期 3
·843-846
·
IF 2.726
Luo Zha,Liu Hao,Shen Wei,Shi Kun,Chen Ankang,Sheng Libo,Sui Yongming,Zou Bo
We used a diamond anvil cell(DAC) to control the deformation of synthesized copper nanorods and silver nanoparticles. And we measured the surface plasmon resonance of copper nanorods and silver nanoparticles, which exhibit redshifts or blueshifts. The surface plasmon resonance shows an abnormal blue shift for both copper nanorods and silver nanoparticles. The solvents of copper nanorods and silver nanoparticles are n -hexane and water, where the pressure loads include quasi-hydrostatic and non-hydrostatic.
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JOURNAL OF MATERIALS SCIENCE
·
2022
·Vol. 57
·期 15
·7491-7502
·
IF 4.682
Zhai Shengnan,Yu Kejing,Meng Chaoran,Wang Hongbo,Fu Jiajia
In this paper, an eco-friendly method of producing hybrid silica aerogels by freeze-drying method (FD) is proposed. In the freeze-drying system, deionized water was the only solvent, hybrid aerogels were prepared by acid–base catalysis and sol–gel method using methyltrimethoxysilane (MTMS) and water–glass as co-precursors. The microstructure, specific surface area, pore size distribution and thermal properties of the hybrid aerogels were characterized and analyzed. It was found that all samples exhibited the dual-mesoporous structures, and the molar ratio of co-precursors had a significant effect on the performance of aerogels. The tap density decreased and the porosity increased with the increase in the molar ratio of MTMS, while the thermal diffusion coefficient and thermal conductivity of aerogel decreased first and then increased. Especially when the molar ratio is 2.0, the hybrid aerogels exhibited excellent insulation performance, such as thermal diffusion coefficient of 0.0183 mm s −1 , thermal conductivity of 0.0460 W(m k) −1 and great thermal stability up to 540 °C. It illustrates that hybrid aerogels have broad application prospects as insulation materials.
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高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2021
·Vol. 127
·期 10
·1-9
·
IF 2.584
Zhang Yu,Cao Ping,Lin Wei,Liu Qiang,Chen Ziyuan,Cao Jun,Yang Guannan,Cui Chengqiang
In this paper, a mixed sintering accelerator of colophony and cetyltrimethyl ammonium bromide (CTAB) was developed to improve the sintering properties of Cu nanoparticles (NPs) paste. With the synergy effect of the mixed sintering accelerator, Cu NPs paste could be well sintered at 260 °C for 30 min under a pressure of 2 MPa, and the shear strength was greatly improved from 15 to 33 MPa. The fracture morphology of the Cu NPs joint transformed from brittle interface failure features to ductile dimple features, and the porosity in the sintered layer was significantly reduced. XRD analysis further confirmed that the synergy of colophony and CTAB could effectively remove the oxides in the Cu NPs paste during sintering, and thereby improve the sintering properties. This work can provide an applicable approach to improve the sintering properties of metal NPs and help to understand the synergy effect of sintering accelerators on the bonding behaviors of metal nanoparticles at low temperatures. Graphic abstract
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Nature Communications
·
2023
·Vol. 14
·期 1
·1-8
·
IF 16.6
Liu Changhao,Zhang Ningsi,Li Yang,Fan Rongli,Wang Wenjing,Feng Jianyong,Liu Chen,Wang Jiaou,Hao Weichang,Li Zhaosheng,Zou Zhigang
Durability is one prerequisite for material application. Photoelectrochemical decomposition of seawater is a promising approach to produce clean hydrogen by using solar energy, but it always faces the problem of serious Cl − corrosion. We find that the main deactivation mechanism of the photoanode is oxide surface reconstruction accompanied by the coordination of Cl − during seawater splitting, and the stability of the photoanode can be effectively improved by enhancing the metal-oxygen interaction. Taking the metastable β -Fe 2 O 3 photoanode as an example, Sn added to the lattice can enhance the M–O bonding energy and hinder the transfer of protons to lattice oxygen, thereby inhibiting excessive surface hydration and Cl − coordination. Therefore, the bare Sn/ β -Fe 2 O 3 photoanode delivers a record durability for photoelectrochemical seawater splitting over 3000 h.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 31
·期 14
·11870-11877
·
IF 2.22
Chen Weigang,Yang Pengyu,Shen Wenfeng,Zhu Chaoting,Lv Dawu,Tan Ruiqin,Song Weijie
Flexible room temperature sub-ppm ammonia (NH 3 ) gas-sensing films based on polyaniline (PANI) nanoparticles were successfully developed on porous polyvinylidene fluoride (PVDF) substrate by in suit chemical oxidative polymerization method. The fabricated PANI/PVDF film sensor, which was synthesized with 0.1 mol/L aniline, possesses the best response value of 24.5% and 2.6% to 1 ppm and 0.1 ppm NH 3 at room temperature, respectively. Furthermore, the PANI/PVDF film sensor shows excellent selectivity towards NH 3 compared with methanol, ethanol, acetone, toluene, and formaldehyde at room temperature. The improved sensing performance is related to the porous PVDF nanostructure and synergetic effects of PVDF and PANI. Finally, the effect of working temperature and relative humidity on the sensing properties of the PANI/PVDF thin film sensor was also discussed and analyzed. The results show the potential application of the flexible PANI/PVDF film sensor for monitoring sub-ppm NH 3 gas under ambient conditions.
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Journal of Flow Chemistry
·
2019
·Vol. 9
·期 4
·211-220
·
IF 2.277
Hu JiaYu,Tian Jiaxin,Wang Kai,Deng Jian,Luo Guangsheng
Herein, a continuous synthetic method of tetraethyl thiuram disulfide (TETD) with CO 2 as a weak acid reagent in a gas-liquid microdispersion reaction system has been described. A microdispersion reaction system comprising two microreactors for CO 2 absorption and diethyldithiocarbamate acid subsequent oxidation reaction was developed. In the first step, the main products of absorption and oxidation reactions were identified. Next, the yield of TETD and selectivity of sodium diethyldithiocarbamate under different flow rates of raw materials, amount of CO 2 , aging effect, and pressure in the microreaction system were determined. The yield reached 89.03% based on 60% H 2 O 2 dosage and the selectivity was 92.86% in less than 3 min of residence time, which was more than 30 min in the batch process. The space time yield in the microreaction system was ~20 times of that achieved in the batch process. The study provides a new successful reference for replacing batch synthesis by a continuous process using a microreaction system.
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Journal of Central South University
·
2022
·Vol. 29
·期 5
·1423-1436
·
IF 2.392
Liu Jun-ru,Li Zhi-bo,Chen Ben,Chou Kuo-chih,Zhang Guo-hua
In order to improve the low ductility of the Mo-Ni alloy, Fe is added and the effects of Ni/Fe mass ratio on the densification behavior, microstructure evolution and mechanical properties of alloy were investigated. The experimental results show that when iron is added to 95Mo-5Ni alloy, the formation of brittle intermetallic phase δ -MoNi at the grain boundary is avoided. Meanwhile, the grain growth of Mo is also effectively inhibited in the sintering process. However, the addition of iron reduces the degree of densification of alloy since the activation effect of Ni is superior to that of Fe. From the experimental results, it could be concluded that the maximum hardness and bending strength are achieved by 95Mo-1.5Ni-3.5Fe alloy, which are HV 614 and 741 MPa, respectively. Combined with the analyses of bending fracture mechanism, the improvement relative to Mo-Ni alloy is likely attributed to the inhibition of the brittle phase.
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