溶胶-凝胶法制备ZnO薄膜及其光催化性能

用溶胶-凝胶法在普通玻璃表面制备了薄膜型ZnO光催化剂,通过XRD、Ab2d、UV-VIS等测试技术对ZnO薄膜进行了表征;以偶氮胭脂红为降解物,考察了薄膜退火温度、镀膜层数、溶液初始质量浓度和反应体系初始pH值对ZnO薄膜光催化性能的影响,并进行了相关机理的探讨．研究表明：溶胶-凝胶法制备的ZnO薄膜呈透明状,薄膜表面均匀分布着球形ZnO晶粒;随着退火温度的升高,ZnO晶粒在17～30mm范围内逐渐增大．光催化实验中ZnO薄膜光催化降解偶氮胭脂红的最佳工艺条件是：退火温度为300℃,镀膜层数为5层,溶液初始pH值为8～9．     

CF4射频容性耦合等离子体对硅橡胶表面双疏改性的研究

利用CF4射频容性耦合等离子体对硅橡胶进行表面双疏改性,用XPS技术分析了处理后硅橡胶表面成分变化,并利用接触角测量研究了表面疏水疏油改性效果.结果表明,CF4射频容性耦合等离子体通过等离子体表面氟化和剥离或刻蚀的相互竞争作用在硅橡胶表面引入大量硅氟基团和少量碳氟基团,两者协同作用使硅橡胶的疏水疏油性能得到大幅提高.     

二氧化钛薄膜光催化性能及改性的研究进展

如何利用二氧化钛薄膜吸收太阳能降解有机污染物是国内外热门研究领域之一。本文针对此领域存在的问题,从二氧化钛的光催化作用原理出发,对影响二氧化钛薄膜的光催化性能的因素进行了详细的归纳总结。此研究为利用无污染方法降解有机物、保护环境和对生态环境的可持续发展的探究具有一定的推动意义。     

Characteristics of permittivity and permeability spectra in range of 2-18 GHz microwave frequency for La1-xSrxMn1-yByO3 （B=Fe, Co, Ni）

Doped LaMnO3 has unusual electromagnetic properties, which makes it possible for this material to be used for absorbing microwave. LaMnO3 systems doped by Sr at site A and Fe or Co, Ni at site B were prepared by sol-gel as an microwave absorption material and their permittivity and permeability spectra were measured by microwave vector network analyzer in the frequency range of 2-18 GHz. A novel phenomenon is discovered that the complex permittivity, complex permeability and electromagnetic loss tangent have suddenly a step change at a certain frequency and the step-change frequency is relevant to content of Sr and Fe or Co, Ni. The samples show mainly dielectric loss when microwave frequency is smaller than the step-change frequency, and mainly magnetic loss when larger than that frequency. It is indicated that anti-ferromagnetic clusters in the material can absorb energy quantum of microwave electromagnetic field to change into ferromagnetic clusters because they can overcome higher energy barrier when the frequency of incident microwave reaches a certain value.     

二氧化钛薄膜光催化性能及改性的研究进展

如何利用二氧化钛薄膜吸收太阳能降解有机污染物是国内外热门研究领域之一。本文针对此领域存在的问题,从二氧化钛的光催化作用原理出发,对影响二氧化钛薄膜的光催化性能的因素进行了详细的归纳总结。此研究为利用无污染方法降解有机物、保护环境和对生态环境的可持续发展的探究具有一定的推动意义。     

纳米La0．8Ba0．2MnO3／Ni粉复合体系的微波吸收性能

采用溶胶-=凝胶法制备La0．8Ba0．2MnO3粉体,并与纳米Ni粉按不同质量比复合,制得复合材料样品。测量样品在2-18GHz频率范围内的复介电常数、复磁导率并计算微波反射系数,分析不同组分对材料微波吸收性能的影响及其可能的吸收机制。研究结果表明：复合体系比单一组分样品具有更好的吸收效果;当La0．8Ba0．2MnO3含量为62、5％时,材料微波吸收效果最佳;当样品厚度为2mm时,大于10dB的吸收频宽达到3．6GHz,最大吸收峰值为24dB;当样品厚度为1．8mm时,大于10dB的吸收频宽达到3．3GHz,最大吸收峰值为44dB;LaMnO,在A位掺杂Ba2＋,其电磁性能将发生变化,再与磁性纳米Ni粉复合,介电损耗和磁损耗的综合作用能使体系的微波吸收效能显著加强。     

退火处理对P型ZnO薄膜光电性能影响的研究

ZnO薄膜为重要的第三代半导体材料,因其优异的光电性能在微电子行业及光电方面诸多领域备受关注,ZnO薄膜的P型掺杂是实现ZnO基光电器件的关键。本文利用射频磁控溅射法通过N-Al共掺技术,在普通玻璃衬底上成功生长出P型ZnO透明导电薄膜。探讨了不同退火气氛和不同退火温度对薄膜样品光电性能的影响,研究结果表明:当氮氧比为9∶1、溅射功率为140W、在400℃真空条件下退火时成功制备出性能优越的P型ZnO薄膜,其电阻率为152Ω·cm,薄膜可见光透射率达到90%以上。     

Improvement of surface hydrophobicity on silicone rubber modified by CF4 radio frequency capacitively coupled plasma

In order to improve the surface hydrophobicity, silicone rubber (SIR) samples were exposed to CF₄ radio frequency (RF) capacitively coupled plasma (CCP). Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectrum and X-ray photoelectron spectroscopy (XPS) were used to observe the variation of the functional groups of the modified SIR. Static contact angle (SCA) was employed to estimate the change of hydrophobicity of the modified SIR. The surface energy of SIR is reduced largely from 27.37 mJ/m² of original SIR sample to 2.94 mJ/m² of SIR sample treated by CF₄ CCP modification at RF power of 200 W for a treatment time of 5 min. According to the XPS, ATR-FTIR and surface energy analysis, it is suggested that the improvement of hydrophobicity on the modified SIR surface is mainly ascribed to the decrease of surface energy, which is caused by the cooperation of the fluosilicic structure of Si-F or Si-F₂ and the fluoric groups of C-CF _n induced by the methyl replacement reaction and residual methyl groups of SIR surface. Foundation item: Project(05JT1034) supported by the Plan of Science and Technology Bureau of Hunan Province, China     

退火处理对N掺杂Al:ZnO薄膜结构及性能的影响

采用射频磁控溅射方法, 常温条件下以N₂作为N掺杂源, 在玻璃基底制备了N掺杂Al:ZnO薄膜。在真空氛围下对样品进行了不同温度的退火处理15 min。通过X射线衍射、霍尔效应测试、紫外-可见光谱和X射线光电子能谱 (XPS) 仪分析了退火对样品结构和光电性能的影响。结果表明真空400℃退火15 min时成功制备出性能优异的p型ZnO薄膜, 其空穴载流子浓度为3.738×10²⁰cm^-3, 电阻率为1.299×10^-2Ω·cm, 样品可见光透射率达到了85%以上。XPS分析说明No受主缺陷的含量大于 (N₂)_o施主缺陷导致薄膜实现了p型转变。     

聚合物低温等离子体表面双疏改性的研究现状

疏水疏油的聚合物材料广泛地应用于国防、工农业生产和日常生活,含氟低温等离子体对聚合物表面双疏改性的研究得到关注。文中总结了以降低聚合物表面能和改变表面粗糙度两方面来提高表面双疏性能的基本原理及相应的实验研究状况,阐明了含氟低温等离子体处理技术能在降低表面能的基础上改变聚合物表面粗糙度,是提高聚合物材料表面双疏性能的有效途径。最后,结合等离子体科学与技术的国内外发展情况,提出表面双疏理论需要进一步发展和完善的方面,展望我国在服装面料等离子体表面双疏改性的自主产业化及其它应用领域的发展前景。