Preparation and optical properties of solid solution semiconductor (Zn x Cd1−x S) doped silica glasses

Semiconductor(Zn_xCd_1−x S) doped silica glasses were prepared by Sol-Gel process andin situ growth technique. The structure of the materials was characterized by X-ray diffraction technique, the particle size of semiconductor crystallites from X-ray patterns was estimated less than 10 nm. From absorption spectra, it is obtained that the absorption edges shifted to short wavelength direction when Zn contents increased, and the absorption edge can be adjusted from 2.46 eV to 2.96 eV by controlling Zn contents. The third-order nonlinear optical susceptibility was studied at 532 nm with 8 ns pulse laser by degenerate four wave mixing (DFWM) technique.     

TiO2的微波辐射Sol-Gel法制备及其光催化性能

采用微波辐射Sol-Gel法在石英砂表面制备负载型TiO2光催化剂，考察不同加热方式。微波功率以及微波加热温度对溶胶质量的影响，微波加热反应制备的溶胶粒子平均粒径小于常规加热反应制备得到的溶胶粒子，微波加热反应适宜条件是微波功率600W，反应温度为90℃、以苯酚为光催化降解研究对象，考察了两种方式制备的负载型TiO2光催化剂的催化性能，实验结果表明微波辐射Sol-Gel法制备的负载型TiO2光催化剂光催化性能也优于常规Sol-Gel法制备的负载型TiO2光催化剂。     

溶胶—凝胶法制备SiO_2薄膜

本研究采用ＴＥＯＳ－ＥｔＯＨ－Ｈ２Ｏ－ＨＣｌ体系原料，应用低温合成技术，成功地在玻璃基底上制备了完整透明的ＳｉＯ２薄膜。对合成材料进行了差热—失重分析，Ｘ射线衍射分析，红外透射光谱分析及理化检验。结果表明，无序ＳｉＯ４四面体网络已经形成，薄膜的固体物理状态可控制为晶态、非晶态，并赋予基底优良的理化性能。     

硬脂酸/二氧化硅复合相变材料的制备

采用溶胶-凝胶法，制备了硬脂酸／SiO2复合相变材料．分别应用差示扫描量热仪（DSC）红外光谱仪（IR）和扫描电镜（sEM）测试了所制备复合材料的相变温度、相变焓、相变可逆性和微观结构．DSC测试结果表明该复合材料具有较好相变可逆性，相变焓和相变温度与纯硬脂酸相比均有降低．IR分析表明硬脂酸与二氧化硅之间是简单的嵌合关系．SEM表明复合材料表面具有多孔结构，改善了复合材料的相变可逆性。     

分子印迹技术研究的新进展

分子印迹技术是制备对特定分子具有特异性识别能力的高分子聚合物的一种技术,本文就近些年来分子印迹技术在合成单体、合成方法以及应用领域等方面取得的新进展进行了综述.     

PA6/SiO2纳米复合材料的动态力学性能研究

在相同的聚合条件下,用三种不同方法制备了PA6/SiO2 纳米复合材料及纯PA6,并对其动态力学行为进行了研究和比较.实验结果表明:加入纳米二氧化硅后,复合材料γ、β松弛峰峰值往高温方向移动.用改进方法制备的PA6/SiO2纳米复合材料的动态储能模量明显高于纯PA6及其它方法制备的复合材料,这对纳米复合材料制备方法的设计有一定的参考价值.     

Preparation and characterization of doubly substituted microwave absorbing material by sol-gel technique for super high frequency applications

Rare earth Dy~(3+)and divalent Mn~(2+)elements substituting W-type hexagonal ferrites Ba_(1-x)Dy_xZn_2Fe_(16-y)Mn_yO_(27)(x=0,0.02,0.06,0.1 and y=0,0.1,0.3,0.5)were prepared by sol-gel method.The thermo-gravimetric analysis(TGA)and differential scanning calorimetry(DSC)was carried out to find the temperature at which single phase can be obtained.XRD patterns indicate the presence of the single phase for all the synthesized samples with the absence of any extra peak due to unreacted material and secondary phases.The occurrence of absorption bands at low wave numbers(563 and 446 cm~(-1)),can be assigned to the stretching vibration of metal and oxygen ions in FTIR spectra,which also confirms the single hexagonal phase for prepared material.The grains are of platelet like structure,which enhances the microwave absorption properties of hexagonal ferrites.The synthesized material exhibits the minimum reflection loss of-20.9 dB at 11.8 GHz frequency,which reflects the applications of this material in super high frequency devices.The microwave conductivity of the material increases with frequency.     

氧化锌薄膜的制备及掺Co2+对结构和性能的影响

采用溶胶-凝胶方法在Si(111)衬底上制备了ZnO:Co氧化锌薄膜,利用X射线衍射(XRD)仪和振动样品磁强计(VSM)分别测试了样品的结构和磁性.实验表明,采用溶胶-凝胶方法制备的掺Co2+氧化锌薄膜具有(002)峰的择优取向,同时ZnO:Co薄膜在室温情况下呈现出铁磁性.     

溶胶-凝胶法制备HEC/SiO2杂化材料的工艺研究

以羟乙基纤维素(HEC)、正硅酸乙酯(TEOS)为原料,采用溶胶-凝胶技术合成了HEC/SiO2有机-无机杂化材料.通过探讨水硅比、HEC含量、溶剂量、干燥控制化学添加剂用量、温度等工艺因素对凝胶化过程,特别是材料干燥体积收缩的影响,得出在本实验条件下合成HEC/SiO2有机-无机杂化材料的优化工艺条件.利用红外吸收光谱、紫外-可见光透射光谱以及扫描电子显微镜等测试手段对合成的HEC/SiO2有机-无机杂化材料进行表征.结果表明,HEC作为有机分散相已经均匀地分散到SiO2基相中,制备的HEC/SiO2有机-无机杂化材料透明,无分相,并可能形成了新的化学键.     

基于MEMS的压电厚膜谐振梁能量收集器的研究

在谐振梁能量收集器中PZT膜材料的制备起着至关重要的作用,复合结构的锆钛酸铅(PZT)厚膜采用溶胶-凝胶方法旋涂在硅基的Au/Cr/SiO2/Si结构衬底的制备方法,主要因为溶胶-凝胶制备方法简单,成本低适合于集成制作.改进PZT组分和和0-3混合法及复合结构的Au/Cr/SiO2/Si衬底,使制备的PZT厚膜避免了厚...