MATERIALS SCIENCE FORUM
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2020
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IF 0
Fei Fei Li,Xue Song Jiang,Jing Wei Li,Bo Yuan Ban,Jian Chen
The one of major impurities in quartz is iron, which has a great impact on the properties of the material and should be be strictly removed in many applications. In this study, a low-energy consumption, simple, fast processing is introduced by combination microwave treatment with different acid leaching. Selective heating of microwaves is used to process quartz, causing local phase changes to improve the purification effect. Acid leaching was used to remove the iron in the quartz matrix. Under optimized conditions, the iron content can be reduced to below 0.167 ppmw with one single purification pass.
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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2015
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IF 0
Feng Ye,Guo Dong Tang,Si Chen,Bo Zhen Wu,Meng Ma,Yan Qin Shi,Xu Wang
L-lysine-based dendritic gelator(G3-C12-G3) was successfully designed and synthesized using a divergent approach and it can self-assemble into nanofibers in MMA followed by gelation. After thermal polymerization of MMA gels, the self-assembly nanofibers modified PMMA nanocomposite can be obtained. SEM studies indicate the embedded supra molecular nanofibres joint each other and form a relative intact gel networkskeleton in PMMA matrix. Impact strength and DMTAmeasurementindicatethe existence of gel network skeleton make PMMA nanocomposite had higher impact strength and storage modulus than pure PMMA. UV-vis spectrophotometer studies indicate PMMA nano-composite retains high light transmittance.
研究领域:
材料科学
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高分子化学
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纳米技术
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2020
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IF 0
Ming Yang,Shun An Chen,Qian Ru Lin,Tao Pang
In this paper, upcovnerison luminescence in Er3+/Yb3+ co-doped NaYF4 nanophosphors was regulated by changing the Er3+ concentration. With increasing the Er3+ concentration, the green and red emissions increased first and then decreased, but the intensity ratio of red to green emission decreased monotonically. To clarify the role of Er3+ doping, the factors including crystal structure, morphology and size of particle, photon absorption, energy transfer, multi-phonon relaxation, population of emissive levels and emission probability of radiative transitions were considered and analyzed. More importantly, we proposed a simple method for discussing radiation transitions based on luminescence temperature sensing.
研究领域:
材料科学
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光学
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2016
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IF 0
Ying Zhou,Zhi Yong Mei,Hai Shao Ye,Wen Wen Su,Xi Zhao,Pei Song Tang
Using La (NO3)3·6H2O, TiCl4 , and citric acid as the main raw materials, nanocrystalline La2Ti2O7 samples were prepared by microwave assisted method. The structure and morphology of samples were characterized by thermogravimetric and differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier Transform Infrared (FT-IR) spectroscopy. The photocatalytic activity of La2Ti2O7 was studied for methyl orange (MO) used as simulated sewage. It was found that the single phase La2Ti2O7 could be obtained through the calcination of microwave processed La2Ti2O7 precursors at 600 °C. The resulted product had an approximate spherical shape and average grain size of 50 nm in diameter. Under UV light, the photocatalytic experiment indicated that the prepared La2Ti2O7 nanocrystalline had high photocatalytic activity for degradation of methyl orange.
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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2016
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IF 0
Yu Mei Zhou,Feng Lin Zhang,Peng Cheng Li,Kun Bai,Shang Hua Wu
AlMgB14 is a very hard and brittle material which need be modified for utilizing as cutting tool materials. In present study, TiB2 and Ni3Al were used to strengthen and toughen AlMgB14 material. The microstructure of the AlMgB14-TiB2-Ni3Al composites was analysized by scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDX) and an X-ray diffractometer (XRD). The hardness and fracture toughness of the AlMgB14-TiB2Ni3Al composites were also examined. The results showed that the major phases in AlMgB14-Ni3Al composites were TiB2, AlMgB14, MgAl2O4 , Ni3Al and NiAl. With the increasing of the amount of Ni3Al, more intergranular fractured features can be found in the fractured surface of the composites, the hardness and fracture toughness of the composites were both decreased comparing to the synthesised AlMgB14. The AlMgB14-TiB2-4wt.% Ni3Al composite has a hardness of 28.1 Gpa and a fracture toughness of 3.14 MPa·m1/2.
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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2020
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IF 0
Shu Guo Dong,Gui Hua Cui,Qian Duan
A novel end-functionalized glycopolymer poly (3-O-methacryloyl-D-glucofuranose) -b-poly (2-Diethylaminoethyl Methacrylate) (PMAGlc-b-PDEA-ZnTAPc) with zinc (II) teraamaninophthalocyanine was synthesized. First, a pH-responsive copolymer PMAIpG-b-PDEA was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Then PMAIpG-b-PDEA reacted with ZnTAPc and deprotected to form a water-soluble and pH-responsive photosensitizer. The structure of the PMAGlc-b-PDEA-ZnTAPc was characterized by 1H NMR and GPC. The photophysical properties were evaluated by UV-Vis and fluorescence spectra. The PMAGlc-b-PDEA-ZnTAPc can generate singlet oxygen species with good singlet oxygen quantum yields (Φ△=0.38), which is believed to be the major cytotoxic reactive oxygen species (ROS) for photodynamic therapy. The ZnPc functionalized glycopolymer will be used as a potential photosensitizer in the fields of photodynamic therapy.
研究领域:
材料科学
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生物医学工程
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药物化学
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2015
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IF 0
Feng Ye,Si Chen,Guo Dong Tang,Bo Zhen Wu,Meng Ma,Yan Qin Shi,Xu Wang
Three kinds of amide dendritic branches, Branch1 (COOH), Branch2 (COOH) and Branch3 (COOH), are successfully synthesized. After mixing with diaminoctane, their self-assembly behavior in methyl methacrylate (MMA) is investigated. The structures of the amide dendritic branches are confirmed by 1H-NMR and Mass spectra (MS). The gelation ability of the amide dendritic gelators is researched through tube inversion experiment, the results of which show that different structures led to quite different gelation ability, including gel-sol temperature and critical concentration to form a stable gel. SEM experiments show that three kinds of gelators formed different gel morphologies in MMA.
研究领域:
材料化学
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超分子化学
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2020
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IF 0
Yuan Lu,Hong Qian Dai,Zhi Min Ou
The magnetic ferroferric oxide nanoparticles were modified with L-lysine to prepare immobilized carriers(Fe3O4-Lys), which was applied to the immobilization of Saccharomyces cerevisiae CGMCC No. 2230. The optimal immobilization conditions for preparation of Fe3O4-Lys-Cells were Fe3O4-Lys 0.01 g, cell dry weight 3 g, pH 7, 3 h, 30 °C. Ethyl R-4-chloro-3-hydroxybutyrate was gained by asymmetric reduction of ethyl-4-chlorooxobutanoate with Fe3O4-Lys-Cells as catalysis. 0.672 mol/L COBE can be converted completely in 40 h in the shaker, while only 24 h in the alternating magnetic field. The conversion and enantiomeric excess(e.e.) of (R)-CHBE reached 100% and more than 99.9%, respectively.
研究领域:
生物化学
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纳米生物学
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酶工程
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2020
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IF 0
Wan Ying Li,Jia Hao Li,Jing Hong Ma,Jing Hua Gong
Surface-enhanced Raman scattering (SERS) spectroscopy technology has broad application prospects in food safety, environmental monitoring, surface science and material analysis because of the characteristics of ultra-high sensitivity and non-destructive testing. However, there are still some challenges in the preparation of SERS substrates. As SERS substrates, the common colloidal noble metal nanoparticles usually show low storage stability and poor repeatability of analytical results. In order to overcome these limitations, a coaxial microfluidic spinning device was designed to prepare flexible SERS substrates in this paper. Based on the microfluidic spinning and subsequent in-situ reduction reaction of AgNO3, novel gel fibers uniformly loaded with AgNPs were successfully prepared. The effects of the concentration of AgNO3 solution and UV irradiation duration on the formation of AgNPs were investigated. Transmission electron microscopy (TEM) showed that the average particle size was about 2.7 nm. The gel fibers loaded with AgNPs were used as SERS substrates to detect 4-mercaptobenzoic acid (4-MBA), which showed obvious Raman enhancement effect and good repeatability. The relative standard deviation of 10 test results was 4.75%, and the detection line range was 10-14-10-5 mol·L-1.
研究领域:
材料科学
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分析化学
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2016
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IF 0
Shu Yu Zhong,Hai Shao Ye,Ji Qi Jiang,Qian Yang,Pei Song Tang
Using La (NO3)3·6H2O, NH4VO3, citric acid as the main raw materials, nanocrystalline LaVO4 sample was prepared by microwave method. The structure and morphology of sample were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-visible diffuse reflectance spectroscopy (DRS) and Fourier Transform Infrared (FT-IR) spectroscopy. The photocatalytic activity of LaVO4 was studied for methyl orange (MO) used as simulated sewage. The XRD and SEM showed that the particle size of LaVO4 was about 80-100 nm. The DRS showed that LaVO4 had optical absorption onset of 356 nm, indicating the optical band gap of 3.48 eV. The FT-IR showed that LaVO4 had vibration peaks of Fe-O and V-O bond. Under UV-light, the photocatalytic experiment indicated that the prepared LaVO4 nanocrystalline had highly photocatalytic activity for degradation of methyl orange.
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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2014
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IF 0
Wen Sheng Linghu,Run Pu Shen
Adsorption-catalytic oxidation of terephthalic acid (TA) from waster water using modified diatomite adsorbent was studied in this paper. Two diatomites were chosen for adsorbents and TA was used as a model compound. The process consists of physic adsorption of TA and catalytic oxidation of TA. The concentration of TA was determined by UV spectrometry. The results indicate that adsorption capacity of diatomite increased with the decrease of pH value of waster water. The equilibrium adsorbed amount of modified diatomite increased with the increase of metal content in the initial metal content range from 0 to 5% for both of Ni, Fe and Cu modified diatomite, and then the equilibrium adsorbed amount decreased after 5% metal content for Ni modified diatomite and in general kept constant for Fe and Cu modified diatomite. The maximum amount of TA adsorbed at the equilibrium stage was 4.40mg/g for Ni-5/RD. The adsorption capacity of raw and modified diatomite decreased obviously with the increase of cycle number in the initial first-fourth of cycle and then decreased very slowly in the 5th-10th of cycle. The Qe of Ni-5/RD, Fe-5/RD, Cu-5/RD and RD in the 10th cycle were 3.12, 2.44, 1.87 and 0.12mg/g, respectively. The result indicated that the modified could be repeatedly used and maintained the adsorption/regeneration performance stably through many batches of operation.
研究领域:
环境科学
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化学工程
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
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2015
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IF 0
Wang Fa Xu,Fa Meng Sun,Jing Bo Liu,Xiao Fang Li,Fa Ai Zhang
A series of porous poly(styrene-divinylbenzene) monoliths (polyHIPE) was synthesized by high internal phase emulsions (HIPE). The effects of the ethanol contents on the microstructure of the polyHIPE were characterized by scanning electron microscopy and mercury intrusion porosimeter. The adsorption and release behaviors of the polyHIPE for a monomer mixture consisting of dicyclopentadiene (DCPD) /styrene (St) (DS, mass ratio of 9/1) were investigated. The polymerization of the mixture DS within pores of the polyHIPE was studied. The results showed that the microstructure of the polyHIPE was significantly influenced by the ethanol content. The increase of ethanol in the HIPE increased the internal pore diameter and decreased the pore volume of the polyHIPE, thus decreased the DS absorption and increased the release rate. The DS monomer can enter the pores(cavities, windows) and fill the original holes after the polymerization. Compared with conventional polymerization of DCPD/St, the poly(DCPD/St) (pDS) obtained from confined spaces possess higher molecular weight, broader molecular weight distribution, and higher Tg. As the pore diameter increased, the effect of space confinement reduced, and the performances of pDS were closed to that prepared by conventional polymerization.
研究领域:
材料科学
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化学工程
·
高分子化学
✓ 已验证
DOI
危险品化学品经营许可证（带存储）