共查询到20条相似文献,搜索用时 140 毫秒
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基于均匀设计优化制备癸酸-棕榈酸/SiO2复合相变材料 总被引:1,自引:0,他引:1
以SiO2作为载体材料,癸酸-棕榈酸作为相变材料制备癸酸-棕榈酸/SiO2复合相变材料.基于均匀设计和多元非线性回归法研究了各因素对复合相变材料吸放湿性能和控温性能的影响.结果表明,各因素对性能影响的主次顺序为:溶液pH值>无水乙醇与正硅酸乙酯的物质的量比>癸酸-棕榈酸与正硅酸乙酯的物质的量比>去离子水与正硅酸乙酯的物质的量比>超声波功率;优化制备方案:溶液pH值为3.62,超声波功率为100W,去离子水与正硅酸乙酯的物质的量比为9.67,无水乙醇与正硅酸乙酯的物质的量比为5.21,癸酸-棕榈酸与正硅酸乙酯的物质的量比为0.52. 相似文献
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碲基复合材料薄膜的三阶非线性光学特性 总被引:1,自引:0,他引:1
采用电化学诱导溶胶-凝胶法在导电玻璃片上制备了具有三阶非线性光学特性的碲基复合薄膜材料. 采用SEM( 扫描电镜)和EDX( X 光电子能谱)对薄膜的表面形貌和组成进行表征; 应用分光光度计得到薄膜的透射光谱、反射光谱、吸收光谱, 并结合脉冲激光器和 Z 扫描方法测量薄膜的三阶非线性光学特性. 实验结果表明制备的薄膜呈网状结构, 表面组分主要包括Si、Te、O元素; 薄膜在波长为1064nm处呈现负的非线性折射效应和饱和吸收的性质, 其非线性折射系数和非线性吸收系数分别为-4.18×10 - 13 m2/W和-1.6×10 - 6 m/W, 表明了碲基复合薄膜有较强的非线性光学效应, 得到三阶极化率为1.13×10 - 14 (m/V)2, 表明复合薄膜具有优良的三阶非线性光学性能. 相似文献
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纳米簇掺杂非线性光学玻璃及其制备方法 总被引:3,自引:0,他引:3
纳米簇掺杂非线性光学玻璃是在诸多性能上优于非线性光学晶体和有机高分子材料的新型的非线性光学材料,介绍了纳米晶簇的引入对材料非线性极化性能及响应速度的影响。以及纳米簇掺杂非线性光学玻璃材料的制备方法和应用前景。 相似文献
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综述了国内外玻璃-氧化铝功能梯度材料的最新进展,详细总结和分析了国外该系材料的制备技术、组成、结构及性能以及国内通过湿法成形制备的材料的烧结行为及机理.国外主要通过渗滤和等离子喷涂2种方法制备该系材料,已经证明,该系材料弹性性能呈梯度变化,能有效抑制Hertzian锥形裂纹生成.与国外等离子喷涂方法制备的材料相比,湿法成形制备的材料不存在分层,无明显的界面问题.已经证明,氧化铝的含量对于该系材料的烧结行为有决定性影响,能够改变基体的烧结机理、抗收缩性能及裂纹扩展行为.最后,阐述了国内外的差距并展望了玻璃-氧化铝功能梯度材料的发展趋势. 相似文献
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通过溶胶-凝胶法将硅烷染料DR1ASD、含硅氧烷PMMA和TEOS在酸催化条件下共水解-缩合制备了新型非线性光学杂化材料PMMA/SiO2/DR1,并运用FT-IR、SEM、UV-vis、DSC/TG和UV-vis等测试方法对其结构和性能进行表征.测试结果表明:杂化材料中有机相和无机相之间通过共价键结合,无相分离出现;杂化材料的玻璃化转变温度(Tg)和热分解温度(Td)分别达到165℃和405℃;电晕极化后杂化材料具有较高的生色团取向有序度(Φ=0.238),并表现出良好的取向稳定性,80℃条件下3h后依然有初始值的79%. 相似文献
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Nicolas Delorme Jean-François Bardeau Alain Bulou Fabienne Poncin-Epaillard 《Thin solid films》2006,496(2):612-618
CO2-plasma is used to introduce functional groups on the uppermost surface of an alkoxysilane self-assembled monolayer (SAM). The structural and chemical modifications of the material surface were monitored by X-ray reflectometry, atomic force microscopy, X-ray photoelectrons spectroscopy and water contact angle measurements. Optimization of the plasma parameters is performed in order to achieve a maximum functionalization and to prevent degradation of the SAM. Finally, the ability of grafting organic compounds onto the plasma modified SAMS was demonstrated by the formation of an alkoxysilane bilayer. 相似文献
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Ohtsuki C Miyazaki T Kyomoto M Tanihara M Osaka A 《Journal of materials science. Materials in medicine》2001,12(10-12):895-899
Poly (methyl methacylate) (PMMA) bone cement is one of the popular bone-repairing materials for fixation of artificial hip joints. Significant problems on the PMMA bone cement are caused by loosening at the interface between bone and the cement, since the cement does not show bone-bonding, i.e. bioactivity. Development of PMMA bone cement capable of bone-bonding has been therefore long desired. The prerequisite for an artificial material to show bone-bonding is the formation of a biologically active bone-like apatite layer on its surface when implanted in the body. The same type of apatite formation can be observed on bioactive materials even in a simulated body fluid (Kokubo solution) with ion concentrations nearly equal to those of human blood plasma. Fundamental researches for bioactive glasses and glass-ceramics revealed that the apatite deposition is initiated by release of Ca2+ ions from the material into the body fluid, and by catalytic effect of Si-OH groups formed on the surface of the material. These findings lead an idea that novel bioactive cement can be designed by incorporation of Si-OH groups and Ca2+ ion into PMMA bone cement. In the present study, PMMA bone cement is modified with 20 mass % of various kinds of alkoxysilanes and calcium salts, and its apatite-forming ability was evaluated in Kokubo solution. The apatite formation was observed on the surface of the modified cements containing 20 mass % of CaCl2, irrespective of the kind of the examined alkoxysilane. On the other hand, the apatite formation was observed on the cement containing CaCl2, Ca(CH3COO)2 or Ca(OH)2, but not on the cement containing CaCO3 or beta-Ca3(PO4)2, even when the cement contains 3-methacryloxypropyltrimethoxysilane (MPS). The results indicate that modification with alkoxysilane and calcium salts showing high water-solubility is effective for providing PMMA bone cement with bioactivity. 相似文献
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原位聚合合成纳米胶囊 总被引:6,自引:0,他引:6
含有羧酸盐亲水基团,端基为可水解缩合的硅氧烷基的预聚体作为疏水物质如甲苯的分散剂获得内含疏水物质,聚聚体为壳层的纳米胶囊,预聚体壳层中的硅氧烷烃水解缩合形成交联,气相色谱测定水解醇深度证明水解缩合在常温24h内完成,透射电子显微镜(TEM)表征了纳米胶囊的形态。 相似文献
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Kim MH Lee J Mo SY Woo HG Yang KS Kim BH Cho MS Jun J Ko YC Roh SH Sohn H 《Journal of nanoscience and nanotechnology》2011,11(2):1722-1725
Si-Si/Si-O dehydrocoupling of hydrosilanes with alcohols (1:1.5 mole ratio), catalyzed by AgNO3 which converted to Ag(0) colloidal nanoparticles, gave poly(alkoxysilane)s in one-pot in moderate to high yield. The hydrosilanes include p-X-C6H4SiH3 (X = H, CH3, OCH3, F), PhCH2SiH3, and (PhSiH2)2. The alcohols include MeOH, EtOH, (i)PrOH, PhOH, and CF3(CF2)2CH2OH. The weight average molecular weight and polydispersity of the poly(alkoxysilane)s were in the range of 1,600 approximately 8,000 Dalton and 1.4 approximately 3.5. The dehydrocoupling reactions of phenylsilane with ethanol (1:3 mole ratio) in the presence of the silver nanocolloid catalyst produced only triethoxyphenylsilane as product. 相似文献
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Junkuo GaoYuanjing Cui Jiancan YuWenxin Lin Zhiyu WangGuodong Qian 《Thin solid films》2011,519(15):5056-5060
A thiophene-vinyl conjugated FTC-type chromophore was synthesized and reacted with 3-isocyanatopropyltriethoxysilane to form alkoxysilane dye. The structure of alkoxysilane dye was confirmed via elemental analysis, FTIR and 1H NMR. Stable and transparent hybrid films were fabricated following sol-gel process of alkoxysilane dye and tetraethoxysilane. The second harmonic generation coefficients (d33) of the hybrid films were measured via in situ second harmonic generation measurement. The d33 value of hybrid films was calculated to be 43 pm V−1 when the chromophore loading density was 20 mol%. Furthermore, the thermal stability of optical nonlinearity was also investigated through a depoling experiment, showing a half decay temperature of 165 °C. 相似文献
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Yuki Totani Atsushi Sugino Toshiki Miyazaki Chikara Ohtsuki 《Materials science & engineering. C, Materials for biological applications》2010,30(4):624-630
Polymethylmethacrylate (PMMA)-based bone cement is widely used for the fixation of artificial joints. However, it is not considered a bioactive material because it lacks the ability to induce a direct bond with bone. In order to improve the long-term stability of cemented fixations, the development of bioactive bone cements is desirable. An essential requirement of a bioactive material includes the induction of bone-like apatite on its surface within the in vivo environment. Previously, we prepared bioactive PMMA-based bone cements by a modification with water-soluble calcium salts and alkoxysilane. Because spatial design may enhance apatite formation on bioactive material surfaces in vivo, we aimed to evaluate the effect of spatial design on apatite formation on modified PMMA-based bone cements in simulated body fluid (SBF). We found that an appropriate spatial design shortened the induction period for the apatite deposition on the modified bone cements. It is expected that osteoconduction would be enhanced in spontaneously created gap between the cement and the host bone leading to tight integration. 相似文献
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LaMeAl11O19陶瓷具有独特的晶体结构, 优异的热力学性能, 低热导率, 高温相稳定性等特点, 是一类非常有应用前景的热障涂层(TBC)材料。本研究通过大气等离子喷涂(APS)制备了LaMeAl11O19/YSZ (Me=Mg, Cu, Zn)双陶瓷层热障涂层。通过对涂层进行火焰热循环测试并结合扫描电子显微镜、X射线衍射仪等分析技术对涂层进行失效分析。结果表明, LaMgAl11O19 (LMA)、LaZnAl11O19 (LZA)和LaCuAl11O19 (LCA)粉末在等离子喷涂过程中发生了分解, 导致三种涂层中磁铅石相含量的差异, 从而影响三种涂层的热循环寿命。由于LaMeAl11O19层与YSZ层的热膨胀系数不匹配以及非晶相重结晶产生的体积收缩, LaMeAl11O19层从YSZ层上剥落。YSZ层暴露在高温下, 加速了烧结和TGO的生长, 又促进了YSZ层剥落。低温下, LaMeAl11O19的热导率随着Me原子序数增加而降低; 高温下, 与LMA和LZA相比, LCA涂层红外发射率最高(0.88, 600 ℃), 削弱了光子传导对热导率的贡献, 导致热导率降低, LCA在高温红外辐射涂层中具有潜在的应用价值。 相似文献
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Jacobsson D Persson JM Kriegner D Etzelstorfer T Wallentin J Wagner JB Stangl J Samuelson L Deppert K Borgström MT 《Nanotechnology》2012,23(24):245601
Non-tapered vertically straight Ga(x)In(1-x)P nanowires were grown in a compositional range from Ga(0.2)In(0.8)P to pure GaP in particle-assisted mode by controlling the trimethylindium, trimethylgallium and hydrogen chloride flows in metal-organic vapor phase epitaxy. X-ray energy dispersive spectroscopy in transmission electron microscopy revealed homogeneous radial material composition in single nanowires, whereas variations in the material composition were found along the nanowires. High-resolution x-ray diffraction indicates a variation of the material composition on the order of about 19% measuring an entire sample area, i.e., including edge effects during growth. The non-capped nanowires emit room temperature photoluminescence strongly in the energy range of 1.43-2.16 eV, correlated with the bandgap expected from the material composition. 相似文献