MATERIALS SCIENCE FORUM
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2020
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IF 0
Zhi Wei He,Hong Xiao Lin,Chun Yan Li,Ashok M. Mahajan,Swati A. Gupta,Mei Zhou
Effect of various silicon sources, such as TEOS, MTES mixed with TEOS and 1,3,5-tris(triethoxymethyl) on SiO2 films was investigated. The synthesized solutions were used as silicon sources to prepare silica-like backbone films. The investigation showed that all precursors can able to produce the flat and uniform films. An FTIR spectrum confirmed the formation of SiO2 in film matrix. The results indicated that the internal microstructure of each film is different. The incorporation of less polar bonds such as F and C was carried out using various Si sources, while the introduction of these sources confirmed through FTIR spectra. Optical properties of the films were carried out by using ellipsometric porosometry (EP) measurement. The leakage current density for the films prepared by using TEOS, MTES and 135TTEB was observed to be 2.8 × 10-7 A/cm2, 2.9 × 10-8 A / cm2, and 4.1 × 10-6 A / cm2, respectively, at 1 MV/cm electric field strength by the IV curves obtained by semiconductor characterization after fabricating MIS devices. The calculated dielectric constants from RI of the deposited SiO2 films were 2.0, 1.9 and 2.5 respectively. When the microstructure of the precursor solution changed, the introduction of atomic morphology or terminal inerted group ratio changed the internal bridging mode of SiO2, and thereby significantly reduced the dielectric constant and improved insulation.
研究领域:
材料科学
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电子工程
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2017
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IF 0
Shuang Lei Peng,Guan Cheng Jiang,Li Li Yang,Xin Liang Li
A hybrid lubricant for invert emulsion drilling fluids (IEDFs), especially for high density (ρ>1.8 g/cm3) IEDFs, was synthesized with expanded graphitic oxide, 1,3-dichloro-2-propanol and N,N-dimethylhexadecylamine in our laboratory. The characterization of the hybrid lubricant was studied through scanning electron microscope (SEM), nuclear magnetic resonance hydrogen spectroscopy (1H NMR) and thermogravimetry analysis (TGA). The results demonstrated that the structure of the hybrid lubricant was consistent with design. This lubricant can adhere to the wellbore and the string directionally and then form a dense protective lubricant film, which causes a drastic reduction of coefficient of friction (CoF) between the rotating drill string and the casing or the rock formation. Application tests in IEDFs with various density showed that 50-70% CoF reduction was observed with 1.0-1.5 w/v% hybrid lubricant. In contrast, CoF reduction of conventional lubricants was only 30-40% at the same condition. And the hybrid lubricant even performs well under high temperature up to 180oC in the drilling fluids with a high density of 2.5 g/cm3 and has little influence on the rheology of drilling fluids. Additionally, the hybrid lubricant is proved easily degradable.
研究领域:
材料科学
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石油工程
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2019
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IF 0
Ai Jia Wei,Wen Li,Li Hui Zhang,Zhen Fa Liu
Spinel powders of Nd-doped LiNi0.5NdxMn1.5−xO4 with different Nd3+ contents (x = 0, 0.01, and 0.02) have been synthesized by a solid-state ball milling method. The samples was characterized by XRD, SEM and EDS. XRD shows the doping of Nd3+ did not destroy the formation of spinel LNMO.The results show that LiNi0.5Nd0.01Mn1.49O4 sample exhibits a higher rate performance with specific discharge capacities of 134.8, 137.2, 136.5, 130.4, 123.8, 106.4, and 83.1 mAh g−1 at 0.2, 0.5, 1, 2, 3, 5, and 7 C (1 C = 140 mAh g−1), respectively. The results indicate that the Nd3+ doping could reduce the electrode polarization and enhance the rate capacities.
研究领域:
材料科学
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电化学
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储能
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2018
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IF 0
Yan Zhen Huang,Xiao Min Chen,Dong Xu Li
Graphene, whose structure is composed of a single-atom-thick sheet of sp2-hybridized carbon atom, provides large specific surface area, excellent mechanical and chemical properties. In this paper, reduced graphene oxide/carbon nanotube (rGO/CNT) composite, which had superior electrochemical performance, was synthesized via a facile, handy and cheap method. Electrochemical tests showed that rGO/CNT composite that the weight ratio of graphene oxide (GO) to CNTs is 7.5 to 1 exhibited the specific capacitance was 346.84 F/g at the current density of 2 A/g in 1 M H2SO4. The good performance of rGO/CNT composite was ascribed to huge surface area of rGO and homogeneous distribution of CNT, which prevented the aggregation of rGO sheets, increased the path of electron circulation and speeded up the electrolyte penetrating into the materials. Therefore, rGO/CNT composite had great potential on supercapacitors.
研究领域:
材料科学
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电化学
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纳米技术
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储能
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2016
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IF 0
Xiu Ju Wang,Xin Lian Shi,Shu Fang Hou,Jian Hua Yang,Kai Li Zhou,Zhong Peng Wang,Li Guo Wang
In this paper, a novel nanocomposite forward osmosis membrane (nTiO2-CTA/CA) was fabricated by introducing nanotitaniumdi oxide (nTiO2) into the cellulose triacetate/cellulose acetate (CTA/CA)-based casting solution using phase inversion methods. Casting composite and preparation--nTiO2 content, blend temperature and coagulating bath temperature--were tested for their effects on pure water flux and salt rejection of membranes. Results revealed that the FO membrane prepared under optimized composition showed excellent desalination performance (high water flux = 5.38 L/m2·h and salt rejection > 97 %). Moreover, SEM images showed that addition of nTiO2 resulted in nanocomposite forward osmosis membrane with a smoother surface. The contact angle of the membranes decreased from 76o to 51° with increase nTiO2 concentration from 0% to 0.10%.
研究领域:
膜科学
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水处理技术
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材料科学
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纳米技术
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环境工程
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2017
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IF 0
Ming Shan Yang,Peng Wei Yin,Hong Liang Tong
The narrow particle size distribution of poly (vinyl silicone) microspheres were prepared by the hydrolysis-polycondensation method with vinyl silane (VTMS) as raw materials. And the influences of pH value, oil/water ratio on the morphology, particle size and distribution of the microspheres were studied. The results shows that the particle size of microspheres decrease with the increasing of the PH value of polymerization, and the particle size has no specific linear relationship with the PH value of hydrolysis reaction, while the oil-water ratio is smaller, single particle size distribution is more narrow, more uniform distribution.
研究领域:
材料科学
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高分子化学
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胶体与界面科学
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2014
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IF 0
Yi Zheng,Shi Yan Chen,Lian Tang,Wei Li Zheng,Chuan Lu,Hua Ping Wang
Bacterial cellulose (BC) /Polypyrrole (PPy) /TiO2 composite membrane was successfully prepared by in situ chemical oxidation polymerization of pyrrole in TiO2 sol into BC membrane matrix with different concentration of TiO2. The results of the field emission scanning electron microscopy observation revealed that the TiO2 nanoparticles coated with PPy were well homogeneously dispersed in the BC matrix. The photocatalytic activity of composite membrane was measured by methyl orange reaction model. Furthermore, the chemical structure of composite membrane and the anatase-TiO2 crystal structure were characterized by FT-IR spectroscopy and XRD analysis, respectively. According to this study, the photocatalytic activity of composite membranes was improved significantly by the addition of TiO2 due to the synergistic reaction between TiO2 and PPy. Besides that, the membrane exhibited the striking flexibility and mechanical properties. This study provided a green and facile method to prepare the BC /PPy /TiO2 composite membrane which would have potential applications in wastewater treatment.
研究领域:
材料科学
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环境工程
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纳米复合材料
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高分子化学
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2020
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IF 0
Qiang Zhang,Meng Hao Li,Ru Xiu Wang,Jia Jia Song,Bin Wang,Xin Li,Xiu Juan Fan,Ji Guang Liu
Thermosensitive conducting composite particles were synthesized using the unsulfonated P(St-NIPAm) as a thermosensitive substrate. A series of characterizations have been performed to study the effects of thermosensitive PANI@poly (St-NIPAm) conductivity performance. Aniline diffused into P(St-NIPAm) particles in solution, and then polyaniline (PANI) was in-situ produced in P(St-NIPAm) particles through oxidation polymerization. The samples showed different particle sizes at different temperatures. The content of conducting polyaniline is dependent on NIPAm feed ratios. The particle electrical conductivity was improved with the increasing NIPAM feed ratios and exhibited thermal responsive electrical conductivity. The thermosensitive conducting composite particles will have wide applications in sensors, for example, they could be used to fabricate smart conductive gel responsive to temperature and moisture.
研究领域:
材料科学
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化学
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纳米技术
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电气工程
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传感器技术
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2019
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IF 0
Ke Xuan Shen,Shi Yong Sun,Ke Wang,Biao Biao Ma,Fa Qin Dong,Yu Quan Ren,Xiao Yu Fan
Amphiphilic functionalized montmorillonite (MMT) has been employed in hydrophobic compounds delivery systems. In the present study, MMT intercalated by 3-aminopropyl trimethoxysilane (APS) was employed for the delivery of the model compounds of resveratrol (RSV). The structure and surface morphology of APS-MMT were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, thermogravimetry, scanning electron microscopy, and contact angle analysis. The loading and release efficiencies of RSV were also investigated. Our study showed that the aminosilane-modified MMT is promising for use in poorly water-soluble compounds carrier systems owing to their natural and excellent performance.
研究领域:
材料科学
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药学
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纳米技术
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2017
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IF 0
Li Peng,Jia Ni Huan,Jing Hua Gong,Jing Hong Ma
Smart hydrogel is a kind of new soft and wet material which can be responsive to external stimuli. Hydrogel fiber owning one dimension size can significantly improve response speed and be easily formed into higher-order assemblies. N-isopropylacrylamide/calcium alginate (NIPA/Ca-alginate) as-spun fiber was generated via microfluidic spinning. Then PNIPA/Ca-alginate hydrogel fiber was prepared through off-chip free radical polymerization of NIPA in the presence of Ca-alginate. The structure and morphology of the hydrogel fiber were characterized by FTIR and SEM. The swelling property and temperature-/pH-response behaviors were also investigated. The PNIPA/Ca-alginate hydrogel fiber had a 3D network porous structure. The thinner the hydrogel fiber, the faster the swelling speed was. Meanwhile, the hydrogel fiber exhibited temperature and pH response.
研究领域:
材料科学
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生物医学工程
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2020
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IF 0
Ming Hong Luo,Yin Ai,Ke Jian Xia
The multilayer composite films consisting of poly (diallyldimethylammonium chloride) functionalized graphene (PDDA-rGO) and phosphomolybdic acid functionalized graphene (PMo12-rGO) were prepared by layer-by-layer self-assembly method. The {PDDA-rGO/PMo12-rGO}n multilayer composite films were used as a support for electro-deposition of Pt particles in situ. Cyclic voltammetry (CV), X-ray photoelectron spectroscopy and scanning electron microscopy were employed for examining the composition, structure, and morphology of the catalyst. Results revealed that the Pt/{PDDA-rGO/PMo12-rGO}n catalyst is successfully prepared and that the multilayer composite films support improves the dispersion of the Pt particles. CV and chronoamperometry were employed to evaluate the electrocatalytic performance for methanol oxidation. Results revealed that the electrocatalytic activity and stability of the Pt/{PDDA-rGO/PMo12-rGO}3 catalyst for methanol oxidation are considerably improved in comparison with that of the Pt/GCE catalyst. The current density for the oxidation of methanol increased from 0.66 mA/cm2 to 1.21 mA/cm2. In addition, the ratio of the forward current density to the backward current density (If/Ib) was 1.92 for Pt/{PDDA-rGO/PMo12-rGO}3 catalyst, corresponding to 1.3 times that of the Pt/GCE catalyst. This result indicated that the multilayer composite films remarkably enhanced the electrocatalytic activity regarding methanol oxidation.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2020
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IF 0
Yu Zhe Lin,Jia Min Zeng,Jing Hong Ma,Jing Hua Gong
Waterborne polyurethane (WPU) is a new type of polyurethane system, which using water instead of organic solvent as dispersing medium. Because of its non-toxicity and environmental safety, WPU is considered as the development direction of coatings and adhesives. However, the mechanical properties of WPU are worse than that of solvent-based polyurethane, therefore, the modification of WPU has received increasingly attention. Meanwhile numerous evidences demonstrate the excellent properties of cellulose nanofibers (CNFs) such as high aspect ratio, low weight and outstanding mechanical strength. Therefore, there is a high expectation for CNFs to be introduced into WPU as reinforcing filler. In this work, a series of CNFs/WPU nanocomposite films were prepared by solution blending. The structure, morphology, thermal behavior and mechanical properties were investigated. SEM results showed that CNFs were evenly dispersed in the WPU matrix. Tensile tests indicated that the modulus and tensile strength of CNFs/WPU nanocomposite films were improved compared with the neat film. While the break elongation of the nanocomposite films decreased with the increase of CNFs content. The synergistic interaction between CNFs and WPU matrix plays an important role in the enhancement of mechanical properties.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
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