MATERIALS SCIENCE FORUM
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2016
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IF 0
Wei Liang Liu,Min Wu,Zhong Tao Shi,Zhao Liang Xu,Jie Ping Ruan
B4C ceramic tapes were prepared by aqueous tape-casting with boron carbide powders as starting material, deionized water as solvent, polymine (PEI) as dispersant, polyethylene glycol (PEG) as plasticizer, poval (PVA) or gelatin as binders. The influences of pH, dispersant content, kind and content of binder on the stability and rheological property of tape slurries were studied. The experimental results indicated that, when the pH was ranged in 3-4, the slurries with good stability and good rheology could be obtained with 0.8 wt% PEI, 4.0 wt% PVA or 6.5 wt% gelatin. PVA as binder made cast tape with certain strength, and gelatin as binder made cast tape with poor strength.
研究领域:
材料科学
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陶瓷工程
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2019
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IF 0
Ke Jia Kang,Peng Fan,Jian Zhang,Qiang Guo Luo,Qiang Shen,Lian Meng Zhang
In this study, the W-Si-C multi-phase composites were fabricated by an arc melting method. With addition of SiC, the grain size of W is obviously reduced, and the small angle misorientation becomes dominate, which is beneficial for the improvement of deformability. The effects of SiC additions (from 0.5 to 3wt%) on the microstructure and mechanical properties are mainly investigated. With 1 wt% SiC addition, the flexural strength reaches the highest value. The self-generation of W5Si3 may enhance the strength and ductility, but too much W5Si3 exists as brittle BP (Brittle to Plastic) microstructure. The highest flexural strength is obtained at approximately 1 vol% W5Si3.
研究领域:
材料科学
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机械工程
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2016
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IF 0
Yan Ou Hu,Hui Qin Lian,Lei Zu,Yue Ting Li,Yang Liu,Xiu Guo Cui,Zhong Kai Hu,Yan Hua Jiang,Lei Wang,Yu Peng Liu,Ben Ze Wu
Ionic polyurethane (IPU) was synthesized as shape memory materials. Poly (tetramethylene ether) glycol with 2000g/mol number average molecular weight were used as soft segment, 4,4-methylenebis (phenyl isocyanate), and 1,2-dihydroxy-3-propanesulfonic acid salt were used to compose the segment of SMP materials. The structure and properties of these IPU films were characterized by Fourier Transform infrared, X-ray diffraction, Thermal gravimetric analysis and Differential scanning calorimeter. The results showed that the glass transition temperature of the IPU increased with the increase of hard segment content. The physical properties in terms of swelling property, water absorption and ion-exchange capacity increased with the improving of sulfonic group content in IPU. The shape memory property of IPU exhibited that the shape fixity ratio and recovery rate improved remarkably with the increase of hard segment content.
研究领域:
材料科学
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高分子化学
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2021
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IF 0
Li Qiong An,Rong Wei Shi,Run Hua Fan,Takashi Goto
Y2Ti2O7 transparent ceramic was fabricated by reactive sintering using spark plasma sintering at 1673 K for 2.7 ks. The sintered body exhibited a cubic pyrochlore structure and uniform microstructure with an average grain size of 2.9 μm. The transmittance reached 73% at a wavelength of 2000 nm after annealing at 1023 K for 21.6 ks.
研究领域:
材料科学
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陶瓷工程
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2020
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IF 0
Nian Liang Gu,Jian Rong Wang,Cai Xia Chu,Juan Chen,Ke Li
In this paper, the effect of simulated seawater on properties of corn straw fibers (CSF) reinforced polypropylene composites was studied. Firstly, CSF was modified with nano-TiO2 particles, and then the modified CSF reinforced polypropylene (PP) composite was prepared. The flexural property and the microstructure of the composites before and after soaking simulated seawater for 21 days were investigated. The results showed that the simulated seawater in short-term immersion could play a role in plasticizing interface and improve the flexural property of CSF/PP composite. After 21 days of simulated seawater immersion, the flexural strength of CS/PP was increased by 18.00%. The modification of TiO2-CSF could improve the flexural property of CSF/PP composite. When the addition of TiO2 was 4 wt.%, the flexural strength reached 44.91 MPa, increased by 17.54% compared with that of unmodified composite.
研究领域:
材料科学
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环境工程
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2014
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IF 0
Si Zhao Zhang,Xue Guang Luo,Feng Ding,Ke Li,Xiao Yan Lin,Gao Long Zhu
Low density polyethylene (LDPE) films added thermal catalyst were investigated at artificial aging time of 0, 10, 20, and 30 days, respectively. The samples obtained were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), gel permeation chromatograph (GPC) and fourier transform infrared spectroscopy (FT-IR). It shows that the surface of film was destroyed via thermocatalytic reactions at lower temperature. In addition, the changes of chemical groups were also observed in the thermocatalytic degradation process. Thus, the validation to the thermocatalytic route has been confirmed over lower temperature excitation. It is hoped that our work may provide a new insight into the degradation of polymeric films at lower temperature.
研究领域:
材料科学
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环境科学
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2020
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IF 0
Yin Hong Ran,Shi Yong Sun,Ke Xuan Shen,Dao Yong Tan,Yu Hang Liu,Liu Li,Yu Quan Ren
Silylation, also known as silane grafting, is frequently used to organically modify montmorillonite (organo-Mt), which of properties were depended on the type of siloxane and intercalated interlayer structure of Mt, for construction of functional materials utilizing in a variety application of industry. We have synthesized organo-Mt using different siloxanes after Mt was firstly modified at three different surfactants of cationic cetyltrimethylammonium bromide (CTAB), anionic sodium oleate (So) and nonionic sorbitan monostearate (Span60) to identifying the effect of surfactants for silylation of Mt. The spectral and structural characters of the obtained products were characterized by a combination of X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), thermogravimetry (TG), and contact angle analysis. The basal spacing of the organo-Mt increased with surfactants loading. We found that CTAB can significantly increase the spacing between layers of Mt from 1.55nm to 1.90nm, load more siloxane on Mt. The average contact angles of CTAB-Mt-APTES and CTAB-Mt-PTES were 69.9±0.3° and 80.7±0.3°, which could be more prone to the interlayer locking effect. Our study showed that the charge of surfactants has significant influence for silylation of Mt, resulting in the loading amount of silane, interlayer structure, and the surface wetting properties.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2014
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IF 0
Cheng Bao Liu,Jun Chao Qian,Feng Chen,Zheng Ying Wu,Zhi Gang Chen
Negative-charged PS microspheres were prepared through emulsifier-free emulsion polymerization method. High-quality PS colloidal crystals were obtained via the horizontal deposition method. Hierarchically ordered macroporous CeO2 sheets were fabricated on fluorine-doped tin oxide (FTO) substrates using PS colloidal crystals as template by a continuous infiltration process. The structure and morphology of the products were characterized by X-ray diffractometer (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and nitrogen adsorption-desorption. The characterized results showed that macroporous CeO2 sheets replicated well three-dimensionally (3D) ordered structure derived from PS colloidal crystals template and possessed a relatively large specific surface area. Moreover, the synthesized hierarchical CeO2 sheets showed the highest photocatalytic activity under solar irradiation and also exhibited remarkable ability to remove methylene blue, suggesting they are promising catalyst for wastewater treatment.
研究领域:
材料科学
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环境科学
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2015
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IF 0
Wei Xing Chen,Xiao Long Zhang,Chun Yan Luo,Ai Jie Ma,Yong Qiang Gu
In order to study the infrared spectral characteristics of side-chain liquid crystal polymer, an infrared monomer containing a permanent dipole azobenzene group spaced from the methacryloyl moiety by a polymethylene segment was synthesized in three steps starting from 4-cyanoaniline. The monomer was polymerized with a push-pull azobenzene monomer, (-)-menthy1 methacrylate in the presence of azobisisobutyronitrile (AIBN) as the radical initiator. Structurally similar amphiphilic polymers were obtained by polymerization of analogous methacrylates in which the polymethylene spacers was replaced by oligo (oxyethy1ene) segments. The obtained polymer was characterized by Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectro photometry (UV-vis), Hot Stage Polarized Microscopy (HS-POM), Differential Scanning Calorimetry (DSC) and Thermo Gravimetric Analyzer (TGA). Its infrared emissivity at different temperatures was tested by Bruker-V70 infrared analyzer. The results showed that the azobenzene poly (methyl methacrylate) (azo-PMMA) has high glass transition temperature(about 40°C), good thermal stability(divied in 294°C) and low infrared emission under 70%.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2020
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IF 0
Shuai Feng,Yan An,Zong Xiang Wang,Kai Sun,Run Hua Fan
In this work, the insulating SiO2 was coated successfully on the surface of reduced iron particles by a sol-gel method to decrease the core loss at low frequency. The scanning electron microscope images and elements analysis confirm that the surface of iron powders particles were covered by a thin insulating layer in the form of uniform core-shell structure. The samples were annealed at 400 °C in N2 atmosphere to obtain better magnetic properties. The annealed SMCs with 10 mL/h dropping rate of TEOS have optimum magnetic properties with low core loss Ps of 280.89 W/kg and high saturation magnetic flux density Bs of 1.038 T at 1000 Hz.
研究领域:
材料科学
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磁学
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2021
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IF 0
Tien Hieu Vu,Van Huan Bui,Ngoc Thang Nguyen
The green synthesis of silver nanoparticles (AgNPs) using herbal plants has gained much attention due to their potential widespread applications, especially in biomedical application to control pathogenic microbes. The aim of our study was to evaluate the antibacterial properties of synthesized AgNPs using aqueous leaf extract of Piper betle L., an important medicinal plant. The AgNPs were identified by UV-Visible spectrometry (UV-Vis), X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectrometry (FT-IR). The presence of surface plasmon band around 420-460 nm indicated AgNPs formation. Spherical nature, unique size-distribution and crystal structure of the AgNPs with diameter around 10-20 nm were affirmed by TEM and XRD analyses. The FTIR measurements showed the presence of bioactive compounds in the extract responsible for the efficient reduction of silver ions and stabilization of the AgNPs. The results from the antimicrobial assays suggested that the biosynthesized AgNPs were potent against pathogenic bacteria including Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus.
研究领域:
纳米生物学
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药用植物学
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微生物学
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
·
2015
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IF 0
Xiao Peng Xu,Si Chen,Yan Qin Shi,Bo Zhen Wu,Meng Ma,Xu Wang
The effect of orotic acid (OA) and its mixtures with calcium stearate (CaSt2) and zinc stearate (ZnSt2) in various ratios on the thermal stability of PVC has been investigated by Congo red and discoloration tests. The results shows that OA acts as a long-term thermal stabilizer for PVC like CaSt2, and the combination of OA and ZnSt2 exhibited a synergistic stabilization effect at a certain ratio. This is due to the ability of OA to absorb HCl released during the degradation of PVC to diminish its catalytic effects, and react with ZnCl2 to stop its catalytic effect for PVC. CaSt2-ZnSt2/OA stabilizers exhibit good synergistic effects with both acceptable initial color and long-term stability for PVC
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
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