JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2016
·Vol. 33
·期 3
·261-265
·
IF 2.267
Shuangbing Li,Jixiao Wang,Song Zhao,Wei Cai,Zhi Wang,Shichang Wang
The spherical silica particles in narrow size distribution with different diameters of 90 nm, 200 nm, 320 nm and 400 nm were prepared by the modified Stöber method and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and dynamic light scattering (DLS). The phase composition of particles was characterized by X-ray diffraction. The results indicated that each of the silica particle samples was in amorphous state. The shear thickening fluids (STFs) comprising 53 vol.% of silica particles and 47 vol.% of polyethylene glycol with molecular weight of 200 g mol −1 (PEG200) were prepared and evaluated. The influence of size and size distribution on the critical shear rate and the intensity of shear thickening were analyzed. The STFs prepared by silica nanoparticles with a diameter of 90 nm showed the giant rheological effect with the critical shear rate of 2.51 s −1 , the largest viscosity of 45,500 Pa∙s and the yield stress of 181 kPa. The experiments and the analysis results demonstrated that the suspensions prepared by nanoparticles have high intensity of shear thickening.
研究领域:
胶体化学
·
流变学
·
纳米材料科学
·
软物质物理
·
功能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2019
·
IF 7.467
Hui-Xian Yang,Dong-Lin Zhao,Wen-Jie Meng,Ya-Qian Wu,Yu Yang,Hao Pu,Rui-Ze Gao
Electrochemical energy storage (EES) devices that combine high-performance are essential to resolve the extreme shortage of non-renewable energy sources and environmental issues. Nickel oxide (NiO) is considered to be a promising EES cathode material because of its ultra-high theoretical specific capacitance, whereas the practical applications are greatly limited with poor rate and cycle performance. Herein, we report the yolk-shelled NiO/Ni composites (YS NiO/Ni) that exhibit good charge storage capability in the aqueous electrolyte with high specific capacitance (2207.3 F g −1 at 1 A g −1 ), exceptional rate capability, and ultra-high cycling stability (95.8% retention after 10,000 cycles). The superior property can be ascribed to the special yolk-shelled structure that exposes more redox reaction active sites, and the associate Ni nanoparticles with flower-like NiO which can improve electron transfer as current collectors.
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米材料
·
功能材料
·
电化学能量存储
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2015
·Vol. 53
·期 12
·1457-1463
·
IF 3.113
Zilong Zhang,Pan Hu,Xiao Li,Hongmei Zhan,Yanxiang Cheng
Novel triarylamine-based coordination-saturated aryl Pd(II) halide complexes ligated by PEt 3 , PCy 3 , and P( o -tol) 3 were successfully synthesized by direct oxidative addition of aryl halide to the corresponding Pd(0) precursors. Suzuki–Miyaura coupling polymerization of 2-(7-halide-9,9-dioctylfluoren-2-yl)−1,3,2-dioxaborinane with these Pd(II) complexes as initiators was investigated for the synthesis of poly(fluorene)s with triarylamine end group. Pd(II) complexes with PCy 3 or P( o -tol) 3 exhibited catalytic activity and realized the catalyst-transfer polycondensation at 75 °C and room temperature, respectively, while the polymerization using Pd(II) catalyst ligated by PEt 3 did not proceed, which indicated that the bulky phosphine ligands could facilitate the reductive elimination and further promote the polymerization. In addition, the dimeric Pd(II) complex with P( o -tol) 3 can convert into monomeric Pd(II) intermediate with an open coordination site, which had a higher activity. The end groups of the afforded polyfluorene were analyzed by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry, in which the Ar/H end groups are indicative of the catalyst-transfer polymerization. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53 , 1457–1463
研究领域:
高分子化学
·
有机合成
·
金属有机化学
·
功能材料
·
聚合反应机理
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2017
·Vol. 135
·期 11
·45974
·
IF 1.86
Wenqi Xian,Lina Song,Baohua Liu,Hulan Ding,Zhao Li,Mengping Cheng,Le Ma
CO 2 copolymer diol-based thermal polyurethane elastomers (PPC-TPU) were prepared by the reaction of CO 2 copolymer diol and methylene diphenyl diisocyanate and chain extender (ethylene glycol/1,4-butanediol/1,6-hexanediol) (EG/BDO/HG). The rheological and mechanical properties of PPC-TPU were analyzed. The effects of shear rate, shear temperature, hard segment content, and variety of chain extender on the properties of PPC-TPU were studied. The results showed that the apparent viscosity (η) of PPC-TPU decreased with the increasing shear rate ( τ ), and the non-Newtonian index ( n ) was less than 1. PPC-TPU exhibited a typical character of pseudoplastic non-Newtonian rheological behavior. The degradation during the processing was obviously inhibited by adding plasticizer and antioxidant. It was also discovered that the apparent viscosity varied with the content of hard segment and chain extender. Under the same temperature (185 °C) and shear rate (50 s −1 ), the apparent viscosity increased considerably with the raise of hard segment content, and the apparent viscosity and tensile strength of PPC-TPU with EG as chain extender was the maximum. It can be seen that with the apparent shear rate increasing, the variation tendency of apparent shear stress levels off, and the nonlinear relationship of τ – γ curve tended to be obvious. PPC-TPU exhibited a typical character of pseudoplastic non-Newtonian rheological behavior. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 45974.
研究领域:
高分子材料科学
·
流变学
·
功能高分子
·
生物基聚合物
·
材料力学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2016
·
IF 3.15
Qiang Huang,Meiying Liu,Junyu Chen,Ke Wang,Dazhuang Xu,Fengjie Deng,Hongye Huang,Xiaoyong Zhang,Yen Wei
Surface modification of nanomaterials with polymers is an effective route to render new functions and improve the performance of the final nanocomposites. Here, a facile method was developed to fabricate polyacrylic acid (PAA)-grafted monodisperse SiO 2 nanoparticles (SiO 2 -PDA-PAA) through a combination of mussel inspired chemistry and Michael addition reaction. To obtain the products, the SiO 2 nanoparticles were first coated with polydopamine (PDA) through self-polymerization of dopamine under rather mild conditions. The PDA thin films can then be further conjugated with amino-terminated PAA, which was synthesized by chain transfer free radical polymerization using cysteamine hydrochloride as a chain transfer agent and acrylic acid as a monomer. The SiO 2 -PDA-PAA nanocomposites were characterized via transmission electron microscopy, Fourier transform infrared spectroscopy, thermal gravimetric analysis, and X-ray photoelectron spectroscopy. The effects of contact time, solution pH, temperature and methylene blue (MB) concentration on the removal of MB were investigated. The results demonstrated that SiO 2 -PDA-PAA showed significant improvement in adsorption efficiency towards MB. The kinetics and isotherm studies showed that pseudo-second-order and Langmuir isotherm models were well fitted the experimental data. The values of thermodynamics parameters such as entropy change ( ΔS 0 ), enthalpy change ( ΔH 0 ) and Gibbs free energy ( ΔG 0 ) were calculated based on the Van’t Hoff equation. The negative values of thermodynamic parameters indicated that the adsorption of MB was a feasible, spontaneous and exothermic process. In summary, we developed a facile method to fabricate SiO 2 -based polymer nanocomposites, which showed obviously enhanced adsorption capability towards MB.
研究领域:
材料科学
·
环境化学
·
纳米技术
·
高分子化学
·
胶体与界面化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMISTRY
·
2014
·Vol. 33
·期 1
·125-130
·
IF 1.04
Ting Zhou,Hao Yu,Mingqiang Liu,Ying-Wei Yang
Carboxylated pillar[5]arene (CP5) macrocycles were modified onto the surface of reduced graphene oxide (RGO) via covalent bonds to form new pillarene-functionalized RGO nanosheets, i.e. , RGO-CP5. The obtained RGO-CP5 nanosheets capable of molecular recognition exhibited much better water-dispersibility and enhanced fluorescence-quenching property as compared with native RGO. This new sensing platform holds great potentials in the sensing and detection of analytes, such as organic dye molecules and pesticides, in aqueous solutions.
研究领域:
分析化学
·
纳米材料科学
·
传感器技术
·
环境监测
·
分子识别
✓ 已验证
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2017
·
IF 2.446
Tengchao Guo,Guoyue Xu,Shujuan Tan,Ning Liu,Jianchao Zhang,Xiangxiong Zeng,Juan Liang
The electronic properties and infrared emissivity of Zn 1-x Mg x O (x = 0, 0.0625, 0.125) were systematically investigated by using the first-principle calculation s based on density functional theory (DFT). The Zn 1-x Mg x O (x = 0, 0.0625, 0.125) powders were prepared by sol-gel method and their infrared emissivity in the wavelength of 8–14 μm was characterized. The results indicate that the infrared emissivity increases with the increase in Mg concentration, which is attributed to the reduction in conductivity and in the real part of dielectric function. Furthermore, the variation in conductivity and dielectric function has been well studied, and a reasonable method to calculate infrared emissivity of semiconductors has been established. It is expected that this method can be used for designing materials with different infrared emissivity and also applied for effectively guiding the experimental investigation.
研究领域:
材料科学
·
凝聚态物理
·
计算材料学
·
功能材料
·
半导体物理
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2019
·Vol. 40
·期 5
·631-637
·
IF 4.914
Zhenmin Xu,Ru Zheng,Yao Chen,Jian Zhu,Zhenfeng Bian
Ordered mesoporous Fe/TiO 2 was prepared by an evaporation-induced self-assembly method. The iron ions were in situ embedded in the pore wall of the TiO 2 framework. The catalyst has excellent light-assisted Fenton catalytic performance under UV and visible light irradiation. X-ray diffraction and transmission electron microscopy results showed that the TiO 2 samples have an ordered two-dimensional hexagonal pore structure and an anatase phase structure with high crystallinity . The ordered pore structure of the TiO 2 photocatalyst with a large specific surface area is beneficial to mass transfer and light harvesting. Furthermore, iron ions can be controlled by embedding them into the TiO 2 framework to prevent iron ion loss and inactivation. After five cycles, the reaction rate of the ordered mesoporous Fe/TiO 2 remained unchanged, indicating that the material has stable performance and broad application prospects for the purification of environmental pollutants .
研究领域:
材料科学
·
环境化学
·
催化化学
·
纳米科技
·
光化学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2009
·Vol. 358
·期 2
·173-179
·
IF 3.19
Guan Huang,Shang-Yue Liu,Yong-An Guo,Ai-Ping Wang,Jin Luo,Chun-Cai Cai
The search for a reusable material as an efficient and economic catalyst for hydrocarbon oxidation is an important field of research. In this study, we investigated the highly effective combination of support and metalloporphyrin provided by manganese tetraphenylporphyrin adsorbed onto a precursor of freshly precipitated aluminium hydroxide, followed by conversion to a manganese porphyrin/boehmite compound. This was characterized using FT-IR, UV–vis spectroscopic techniques, N 2 BET analysis, X-ray powder diffraction, transmission electron micrograph technique and thermal analysis. Aerobic oxidation of cyclohexane has been investigated using the compound as a catalyst under mild conditions and in the absence of any solvent and reductant. The results indicate that it has higher catalytic activity than manganese tetraphenylporphyrin and the corresponding chitosan-supported catalyst. In particular, the catalyst exhibits good atom economy for cyclohexane oxidation, high catalyst turnover number, and good ketone and alcohol selectivity. In particular, it has excellent reusability, with no change in original catalytic activity; a quantity of catalyst containing only 1 mg of Mn TPP can be reused 8 times under the promotion of beomite (BM). In addition, we examined the reaction conditions for the use of such nanoparticle-supported manganese tetraphenylporphyrin as a mild and environmental friendly oxidation catalyst.
研究领域:
催化化学
·
纳米材料
·
绿色化学
·
有机氧化反应
·
多相催化
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 67
·62675-62679
·
IF 3.289
Yongzheng Wang,Jing Ye,Yu Shen,Mingjiang Xie,Shuangshuang Yang,Chao Liu,Xiangke Guo,Luming Peng,Weiping Ding,Xuefeng Guo
Anatase-type titania with ultrathin nanosheet morphology and sintering-resistant structure was constructed from monolayer titanate nanosheets isolated by uniform silica nanoparticles. The obtained anatase titania nanosheets possess high accessible surface area, ultrathin thickness (∼0.6 nm), dominant (116) facets exposed, wide bandgap and exhibits excellent photocatalytic activity.
研究领域:
材料科学
·
纳米科技
·
光催化
·
无机化学
·
能源材料
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 53
·期 24
·16383-16392
·
IF 2.993
Wu Yadong,Wang Fang,Li Xianglong,He Jinmei,Huang Yudong
The synergic effect between each component in composite membrane has created a new concept to fabricate membrane materials and widen their applications. Previous trials have suggested that micrometer-scale aramid fiber (MAF) could be effectively split into nanoscale aramid fiber (NAF) by dissolution in DMSO/KOH. Addressed herein is a time-saving approach to incorporate graphene oxide (GO) together with NAF to fabricate composite membranes through π–π stacking interactions. NAF–GO composite membranes (GO/NAF) containing gradient contents of GO have been prepared using absolute ethanol as proton donor, making the drying process facile and fast. The obtained composite membranes exhibit excellent hydrophilicity and enhanced mechanical performance. The chemical structure, morphology, crystallization and mechanical strength of GO/NAF composite membranes are characterized, respectively, and the hydrophilicity of GO/NAF is also evaluated by static water contact angle measurements. In the case of medium GO content (1 wt%) used in this study, the composite membrane possesses both optimal mechanical performance and better hydrophilicity compared to other supplementations, indicating that absolute ethanol is a promising proton donor for flocculation, which makes the post-treatment process more economic.
研究领域:
材料科学
·
高分子化学
·
纳米技术
·
膜科学
·
表面科学
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2020
·Vol. 31
·期 11
·2480-2491
·
IF 2.578
Po Hu,Xinyu Zheng,Jiwei Zhu,Baolin Wu
Chicken feather keratin (CK), a biomaterial that contains a large amount of nitrogen is extracted from chicken feathers and has significant potential for use as a flame retardant. In this study, CK and 9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide (DOPO) were added in different amounts to an epoxy resin (EP), and their flame retardancy and smoke suppression effects were studied. The results showed that CK exhibits a good flame-retardancy effect and better smoke suppression characteristics than those of DOPO when added to EP. Furthermore, it greatly reduces the CO yield in smoke. While the EP samples with DOPO showed better flame-retardancy properties than those of the samples with CK, they also produced more smoke, which had a higher CO content. Furthermore, when CK and DOPO were added to EP together, the flame-retardancy characteristics of the samples varied with the CK/DOPO ratio. Then the pyrolysis of all samples was divided into two stages based on thermokinetics analysis and the activation energies of these samples in the two stages were investigated. Finally, the flame-retardancy mechanism was discussed. When samples burn, the PO· free radicals derived from DOPO combine with H· and OH· to induce a quenching effect. In addition, the phosphate resulting from the decomposition of DOPO promotes the formation of the char layer. At the same time, the noncombustible gases generated during the pyrolysis of CK cause the char layer to expand and remove some of the heat. Thus, CK and DOPO synergistically improved the flame retardancy of EP.
研究领域:
高分子材料科学
·
阻燃化学
·
热分析
·
环境友好材料
·
生物基添加剂
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）