INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
·
2020
·
IF 3.407
Weiqiang Hu,Zhi Dong,Hui Wang,Tansir Ahamad,Zongqing Ma
Oxide-dispersion-strengthened (ODS) tungsten based alloys with high performance were synthesized by optimized freeze-drying with PVP and PEG polymer dispersant additives and subsequent low temperature sintering . The pre-freezing principle developed firstly in our work shows that fast cooling rate and polymer dispersant additives contribute to the refinement and uniformity of precursor powders. The optimized freeze-dried W-Y 2 O 3 composite powders possess an average grain size of 9 nm, which can be attributed to the steric hindrance provided by polymer dispersants during freeze-drying and voids left by the decomposition of polymer dispersants during calcination . After sintering at low temperature, the W-Y 2 O 3 alloys have ultrafine W grain (210 nm) and nano second phase particles (<50 nm) dispersed in W matrix while maintaining a high relative density of 97.8%. These factors mentioned above lead to the microhardness and compressive strength as high as 721 ± 31 HV 0.2 , 814 MPa respectively, accompanied by a high total deformation plasticity of above 50%. These results indicate that the optimized freeze-drying and subsequent low temperature sintering is a promising way to fabricate ODS tungsten based alloys with high performance.
研究领域:
材料科学
·
金属学与冶金工程
·
纳米材料
·
复合材料
·
结构材料
✓ 已验证
DOI
高影响因子
CARBON
·
2018
·
IF 7.082
Yiwen Hu,Yongxin Wang,Zhixiang Zeng,Haichao Zhao,Xuewu Ge,Kai Wang,Liping Wang,Qunji Xue
Dispersion of Graphene in water is conducive to their practical applications as lubricating additive in water-based fluids due to their safety, low cost and environmental-friendliness. But owing to its hydrophobicity , it is difficult to achieve stable aqueous graphene suspension. Here, we use the Toluene-2,4-diisocyanate as bridging agent between hydrophilic Poly (ethylene glycol) (PEG) and ethanolamine to prepare the amino-containing PEG (PEG-NH 2 ), followed by covalently grafting PEG-NH 2 onto the surface of carboxylaed graphene (G-COOH) nanosheets to synthesize the PEGlated graphene (PEG-G) via facile amidation under mild conditions. The physical, chemical properties of product were characterized by Fourier transformed infrared spectra (FTIR), Raman spectra , X-ray photo electron spectroscopy (XPS) and so on. Transmission electron microscopy (TEM) and scanning probe microscope (SPM) were utilized to observed the morphology of G-COOH and PEG-G. The frictional properties of PEG-G as nanoadditive of water-based lubricant were characterized by UMT-3 tribometer, following with analyzes on wear surfaces by 3D laser scanning confocal microscopy . Based on the results of characterization, the PEG-G was prepared successfully and the dispersion shows superior friction-reducing and anti-wear properties owing to the formation of fluid adhesive film and carbon protective film, especially the concentration of PEG-G in water is 0.05 wt%.
研究领域:
材料科学
·
纳米科技
·
表面工程
·
摩擦学
·
高分子化学
·
应用化学
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2016
·Vol. 27
·期 11
·1501-1507
·
IF 1.823
Zhubo Liu,Bing Zhou,A.V. Rogachev,M.A. Yarmolenko
Polytetrafluoroethylene (PTFE) composite coatings doped copper acetate and polyurethane (PU) were prepared on rubber substrate by low-energy electron beam dispersion technique. The effects of dopant and glow discharge treatment on the surface morphology, structure and tribological properties of the coatings were investigated. The results showed that Cu–PTFE composite coatings form uniform surface and dense column structure with spherical aggregations under glow discharge treatment. PU coating shows the large size of protuberance structure but PU–PTFE coating presents spherical structure. Both of the coatings become relative dense and smooth after discharge treatment, and Cu–PU–PTFE composite coatings possess a smoother surface and lower polar component of surface energy. Cu doping weakens the crystallinity and ordering degree of composite coatings, but glow discharge increases the ordering degree and branched structure of C―H groups. Friction experiment indicated that Cu fails to improve the wear resistance of PTFE coatings but glow discharge treatment can do it. Cu–PU–PTFE coatings after discharge treatment have the higher wear resistance and lower coefficient of friction. Copyright © 2016 John Wiley & Sons, Ltd.
研究领域:
材料科学
·
表面工程
·
高分子材料
·
摩擦学
·
等离子体物理
·
涂层技术
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2020
·
IF 5.065
Yawei Song,Kuanjun Fang,Mohd Nadeem Bukhari,Kun Zhang,Zhiyuan Tang
Inkjet printability of dye-based inks including stability, jetting morphology, and color performance is difficult to maintain due to the strong dye molecular interaction. Herein, carboxyl-rich polymer nanospheres were introduced to the dye-based inks, forming a novel kind of multilayer dye/polymer nanospheres to enhance the inkjet printability. Disperse dyes were firstly loaded into poly (styrene-butyl acrylate-methacrylate) nanospheres at 95 °C, and then encapsulated by poly (styrene-methacrylate) polymer layer through seed polymerization to form multilayer structure. The results showed that hydrogen bonds were formed between disperse dyes and nanospheres, and the interaction was enhanced when more carboxyl groups were polymerized on nanosphere surface. Moreover, due to the high surface carboxyl group content, the stability was significantly improved in comparison with disperse dye suspension. After inkjet printing , the dye/nanosphere dispersion showed more stable droplet formation and higher color depth. Besides, because of the self-curing ability of polymer nanospheres, satisfactory fastness was obtained for practical application. The results from this study can promote the optimization of dye-based ink formulations, and show great potential in obtaining high quality inkjet printing products.
研究领域:
材料科学
·
高分子化学
·
表面化学
·
印刷电子学
·
功能材料
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY
·
2019
·
IF 1.267
Yue Yang,Zihui Liu,Hao Chen,Shengqing Li
A simple and fast method of low-density solvent based dispersive liquid-liquid microextraction (LDS-DLLME) followed by high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS) has been developed for the speciation analysis of organoarsenic and inorganic arsenic in water samples. The low-density solvent (octanol) was given as the organic phase and injected into the aqueous sample (donor phase) with methanol as the disperser. With As (V), As (III), p-APAA, 4-HPAA, ROX and PAA as target species, factors of LDS-DLLME including pH value, anionic carriers, elution conditions and extractant, were studied in detail. Besides, volumes of solvents were further optimised by response surface methodology. Under the optimal conditions, the limits of detection for four phenylarsenics and arsenate were in the range of 0.001–0.039 μg L−1. The relative standard deviations (RSDs) were 3.6–9.4% and the enrichment factors varied from 6.2 to 70.8. The proposed method of LDS-DLLME-HPLC-ICP-MS was satisfactorily applied to the determination of six arsenic compounds in water samples with recoveries of 81.8–111.7% for the spiked lake water samples.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Liyuan Zhang,Shu Yang,Yuekun Lai,Hui Liu,Yiang Fan,Cao Liu,Haiying Wang,Liyuan Chai
Gaseous Hg 0 is one of the most deadly and hard-to-dispose pollutants. The oxidation of Hg 0 is a promising route, but the rational design and synthesis of highly efficient catalysts still remain grand challenges. Herein, CuO@Cu 2 O (or Cu x O) heterostructured nanoparticles uniformly monodispersing on porous carbon monolith were designed and successfully synthesized using oligo( m -phenylenediamine)-Cu 2+ complex as raw material. The Cu x O-carbon catalyst contains ∼28 wt% of Cu. Based on density functional theory calculation, the CuO@Cu 2 O junction interfaces can accelerate the Hg 0 oxidation by significantly reducing the energy barriers of reaction. Only 1 mg of the catalyst can catalyze the oxidation of more than 90 % of Hg 0 with [HCl] = 0.5 ppm, [O 2 ] = 6 vol%, T = 150 °C. The poisoning effect of either SO 2 or H 2 O on the catalysts is weak. Moreover, a long-term test confirmed that the Hg 0 oxidation rate can maintain more than 90 % even in the co-presence of SO 2 (5000 ppm) and H 2 O (10 vol%).
研究领域:
环境催化
·
材料化学
·
大气污染控制
·
纳米材料
·
表面科学
✓ 已验证
DOI
高影响因子
Arabian Journal of Geosciences
·
2019
·Vol. 12
·期 7
·256
·
IF 1.141
Li Weitao,Wei Falin,Xiong Chunming,Ouyang Jian,Zhao Guang,Shao Liming,Dai Mingli
Aiming at deep profile control in water flooding reservoirs, a heterogeneous combination flooding system, composed of dispersed particle gel (DPG) and a zwitterionic surfactant (THSB), was developed. The mean particle diameter was adjusted and then the DPG morphology and diameter were characterized using a laser scanning, confocal microscope, and dynamic light scattering. The effects of DPG concentration, temperature, pH, and salinity on THSB interfacial tension (IFT) were investigated. A method for determining DPG concentration was proposed, and the dynamic retention and migration mechanisms of the particles were evaluated, using cores with different permeabilities. Finally, the oil displacement mechanism of the combination flooding system was explored through visual simulation experiments and scanning electron microscopy. The results showed that the particle diameter was 2.5 μm, that compared with a surfactant system, the IFT of the combination flooding system was relatively low, and that the temperature, pH, and NaCl content of solutions had little effect on THSB IFT. Since specific matching relationships between DPG particles and reservoir pore throats existed, the retention amount and injection pressure were improved with the increased core permeability. Visual simulation experiments revealed the oil recovery mechanism of the combination flooding system. This combination flooding system can be used in reservoirs under varied conditions, as the particle diameter can be adjusted on a case-by-case basis, and the THSB surfactant proved to be high-temperature resistant and high-salinity tolerant. The combination flooding system can be applied to deep profile control and oil displacement, in oil fields.
研究领域:
石油工程
·
提高采收率
·
油田化学
·
渗流力学
·
油气田开发
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2019
·Vol. 57
·期 15
·1653-1663
·
IF 2.591
Bin Li,Yan Shi,Zhifeng Fu
Two kinds of Schiff base, N , N ′-dibenzylidene-1,2-diaminoethane (NDBE) and N , N ′-disalicylidene-1,2-diaminoethane, have been found as efficient organic catalyst for reversible complexation-mediated radical polymerization (RCMP) of methyl methacrylate (MMA) for the first time. The polymerization results show obvious features of “living”/controlled radical polymerization. Well-defined and low-polydispersity polymers ( M w / M n = 1.20–1.40) are obtained in RCMP of MMA catalyzed by Schiff base at mild temperature (65–80°C). Moreover, Schiff base also exhibits a particularly high reactivity for RCMP of MMA with in situ formed alkyl iodide initiator. The polymer molecular weight and its polydispersity ( M w / M n is around 1.20) are well controlled even with high monomer conversion. Notably, when the dosage of azo initiator is same as the dosage of iodine, the polymerization could also be realized in the presence of NDBE. The living feature of synthesized polymer is confirmed through the chain extension experiment. In short, Schiff base is a kind of high-efficient catalyst for RCMP and reverse RCMP of MMA, which can be one of the most powerful and robust techniques for polymer synthesis. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1653–1663
研究领域:
高分子化学
·
聚合物合成
·
催化化学
·
功能材料
·
有机合成方法学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 137
·期 43
·49320
·
IF 2.52
Zhenggang Luo,Huijian Ye,Jiawei Hu,Te Hu,Boyuan Zhang,Xuanhe Zhang,Lixin Xu
A strategy for preparing ethylene-vinyl acetate (EVA)/graphene nanocomposites from liquid-phase exfoliated graphene has been explored with the use of a pyrene-functionalized hyperbranched polyethylene (HBPE) ternary copolymer, HBPE@Py@PMA, as stabilizer for graphite exfoliation. The HBPE@Py@PMA was synthesized by combining the Pd-diimine-catalyzed chain walking ternary ethylene copolymerization and atomic transfer radical polymerization techniques and has been confirmed to possess a HBPE core simultaneously bearing pyrene terminal groups and polymethacrylate side chains. As stabilizer, it is found to effectively promote graphite exfoliation in CHCl 3 to render high-quality few-layer graphene with an efficiency as high as 43%. Meanwhile, it can be steadily adsorbed on the exfoliated graphene surface to concurrently render functionalized graphene well dispersible in EVA matrix with strong interfacial interactions. This allows us to obtain EVA/graphene nanocomposites from resulting graphene dispersion through simple solution mixing process. By adding only 0.5 wt% of graphene, the dielectric constant of resulting composite increases by 55% compared to pure EVA, with a dielectric loss only 0.012. The role mechanism of the HBPE@Py@PMA for promoting graphite exfoliation in CHCl 3 and the formation of EVA/graphene nanocomposites from the resulting graphene has been proposed.
研究领域:
高分子化学
·
纳米复合材料
·
材料科学
·
胶体与界面化学
·
功能高分子
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2019
·Vol. 57
·期 15
·1645-1652
·
IF 2.591
Yangyi Sun,Hua Zhang,Weichang Han,Huajun Huang,Dongming Qi
This article reports a facile controllable approach to prepare monodisperse nonspherical colloidal particles with cavity structures by one-pot soap-free emulsion polymerization of styrene (St), 3-(trimethoxysilyl)propyl methacrylate (MPS), and acrylic acid (AA). In our strategy, only by varying the feeding time of AA to the as-polymerized St and MPS, the nonspherical latex particles with single cavity of different surface roughness and multicavity structures could be successfully synthesized. The depth and width of the cavity can be also easily controlled by adjusting the amount of MPS and AA. A possible formation mechanism is proposed on the basis of experimental results. These nonspherical colloidal particles, which have controllable cavity structures, are good building blocks or templates for the construction of functional coating and complex colloidal architectures. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1645–1652
研究领域:
高分子化学
·
胶体与界面科学
·
功能材料
·
纳米材料
·
聚合物合成
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2019
·Vol. 30
·期 11
·2781-2789
·
IF 2.162
Tingjun Zhong,Richard J. Mandle,John W. Goodby,Lanying Zhang,Cuihong Zhang
In this work, the thiol-ene click reaction is employed to fabricate polymer-dispersed liquid crystal (PDLC) films by photoinitiated polymerization. The PDLC films are prepared by systematic variation of key conditions: variety and content of -ene monomer, liquid crystal (LC) content, curing time, and curing light intensity. We find that both the morphologies and electro-optic properties of these films are adjustable. When increasing the length of alkyl main chain of -ene monomers, the driving voltages reduce, but in turn, the contrast ratio decreases. Increasing -ene monomer content raises the driving voltages as well as the response time, and the increase of LC content lowers the driving voltages but has a negative effect on the contrast ratio. The changes to the curing conditions (both curing time and UV light intensity) can be used to modify the driving voltages, response time, and contrast ratios of PDLC films. These comparative studies will elucidate new insights in commercial applications of intelligent PDLC films.
研究领域:
材料科学
·
高分子化学
·
软物质物理
·
光电功能材料
·
智能材料
✓ 已验证
DOI
高影响因子
DYES AND PIGMENTS
·
2016
·
IF 4.055
Da-fa Yang,Xiang-jun Kong,Dan Gao,Hong-sheng Cui,Ting-ting Huang,Jin-xin Lin
Reactive disperse dyes with mono- and bi-acyl fluoride reactive groups have been synthesized using a simple and convenient method. The structures of these dyes have been defined by 1 H, 13 C and 19 F NMR. The cotton dyeing in supercritical carbon dioxide (Sc CO 2 ) with dyeing temperature varying from 60 °C to 120 °C and time between 1 h and 3 h and with the concentration of 0.5% owf (on weight of fabric) have been studied. Significant improvement of the color fastness of washing and rubbing has been observed owing to the covalent bond formed between the reactive group of dyes and the functional group of cotton fibers . Besides, the dyed fabrics possess favorable fastness properties , indicating the achievement of lower-temperature dyeing of cotton in Sc CO 2 . Additionally, the end products meet the garment dyeing standards as well. A mechanism of dyeing process is tentatively speculated meanwhile.
研究领域:
纺织化学
·
染整工程
·
绿色化学
·
高分子材料与纤维科学
·
环境友好染色技术
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）