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71.
72.
采用溶胶凝胶技术,结合碱性催化和低表面张力溶剂交换以及非活性CH3基团置换修饰,在常压条件下成功地制备了孔隙率为77%、折射率为1.12纳米多孔SiO2气凝胶薄膜.采用氨和水蒸气混合气体热处理技术提高薄膜的耐磨性、附着力等力学特性.使用透射电镜(TEM)、扫描电镜(SEM)分别观察了溶胶的颗粒结构和薄膜表面形貌.应用傅里叶转换红外光谱仪(FTIR)研究了薄膜经表面基团修饰前后的红外吸收光谱以及后处理对薄膜红外ω4(TO3)吸收峰位置和半宽度的影响.采用椭偏仪测量薄膜的厚度和折射率.耐摩擦和附着力测试表明:
关键词：
SiO_2气凝胶薄膜
溶胶凝胶技术
纳米多孔结构 相似文献
73.
金纳米空心半球壳膜的可调谐光学性质研究 总被引：1，自引：0，他引：1
以单层聚苯乙烯微球阵列为模板,通过控制其表面金膜蒸镀时间,制备了具有不同厚度的空心半球壳结构的金纳米膜.利用扫描电子显微镜和自制光谱仪分别测量了金膜表面形貌和其透射光谱,并分析了金膜形貌与其光学性质间的关系,同时以4-巯基苯胺为探针分子测定了金膜的表面增强喇曼散射效应.结果表明,该金纳米膜的表面等离子体共振波长随膜厚度增大而发生红移,在可见与近红外波段较宽范围内可调谐,并且,当金膜共振波长与入射激发光波长较近时,探针分子可产生出较强的表面增强喇曼信号.同时,对该现象的产生机制也进行了理论解释. 相似文献
74.
由于薄膜衍射元件表面质量密度低、面形公差宽松,可将其作为空间大口径衍射望远系统的主镜,构成具有超大口径、轻质量、高集光率的光学载荷,提高对地球不受干扰、实时观测能力.本文分析了衍射元件的加工公差、衍射望远系统两部分空间相对位置的系统公差,提出了衍射望远系统两部分空间相对位置测量方法,并分析了测量准确度.该方法利用两种不同结构的计算全息元件,将激光光源在CMOS有源探测器上形成两个聚光光斑,实时分析两光斑的相对位置,可以精确测量偏心量和倾斜量,测量准确度分别可达50μm和0.003°,为未来大口径衍射望远系统在空间的实施奠定了基础. 相似文献
75.
Jian-An Li Letian Zhang Dr. Chunlei Wu Zihao Huang Shufeng Li Huaqing Zhang Qingchen Yang Dr. Zhu Mao Prof. Suilian Luo Prof. Cong Liu Prof. Guang Shi Prof. Bingjia Xu 《Angewandte Chemie (International ed. in English)》2023,62(7):e202217284
In this work, an efficient polymer-based organic afterglow system, which shows reversible photochromism, switchable ultralong organic phosphorescence (UOP), and prominent water and chemical resistance simultaneously, has been developed for the first time. By doping phenoxazine (PXZ) and 10-ethyl-10H-phenoxazine (PXZEt) into epoxy polymers, the resulting PXZ@EP-0.25 % and PXZEt@EP-0.25 % films show unique photoactivated UOP properties, with phosphorescence quantum yields and lifetimes up to 10.8 % and 845 ms, respectively. It is found that the steady-state luminescence and UOP of PXZ@EP-0.25 % are switchable by light irradiation and thermal annealing. Moreover, the doped films can still produce conspicuous UOP after soaking in water, strong acid and base, and organic solvents for more than two weeks, exhibiting outstanding water and chemical resistance. Inspired by these exciting results, the PXZ@EP-0.25 % has been successfully exploited as an erasable transparent film for light printing. 相似文献
76.
Donglin Chen Jinpeng Li Xudong Mei Xiaoyun Liu Peiyuan Zuo Xunlin Qiu Qixin Zhuang 《Angewandte Chemie (International ed. in English)》2023,62(51):e202315143
With the rapid development of integrated circuits towards miniaturization and complexity, there is an urgent need for materials with low dielectric constant/loss and high processing temperatures to effectively prevent signal delay and crosstalk. With high porosity, thermal stability, and easy structural modulation, covalent organic frameworks have great potential in the field of low dielectric materials. However, the optimization of dielectric properties by modulating the conjugated/plane curvature structure of covalent organic frameworks (COFs) has rarely been reported. Accordingly, we herein innovatively prepare COF films with adjustable planar curvature, hence possessing ultralow dielectric constant (1.9 at 1 kHz), ultralow dielectric loss at 1 kHz (0.0029 at room temperature, 0.0052 at 200 °C), high thermal decomposition temperature (5 % weight loss temperature, 473 °C) and good hydrophobicity (water contact angle, 105.3°). Also, to the best of our knowledge, we are the first to report that the resulting COF film enables high surface potential (≈320 V) for one week, attributing to its intrinsic high porosity, thus presenting great potential in electret applications. Accordingly, this innovative work provides a readily available and scalable idea to prepare materials with comprehensively excellent dielectric and electret properties as well as high processing temperatures simultaneously for advanced electronic device applications. 相似文献
77.
利用射频磁控溅射技术在LaNiO3/SiO2/Si基底上制备了Pb(Mg1/3Nb2/3)O3-PbTiO3/CoFe2O4和Pb(Mg1/3Nb2/3)O3-PbTiO3/CoFe2O4/Pb(Mg1/3Nb2/3)O3-PbTiO3两种复合薄膜.我们采取了三种退火条件对复合薄膜进行退火处理,研究两种复合薄膜的晶体结构、电学和磁学性能.通过对两种复合薄膜的结构的分析,发现两步法退火后得到复合薄膜同时存在纯钙钛矿相和尖晶石相两种结构.铁电性能测试表明:两种复合薄膜均具有较好的铁电性能,其中三层复合薄膜的剩余极化强度Pr最大可以达到14.9 μC/cm2,这要归因于多层复合薄膜内部的应力-应变效应和界面耦合效应.在电场强度为80kV/cm的漏电流密度数量级仅10-5A/cm2,其导电机制在高电场区满足Schottky机制.介频性能测试表明:复合薄膜的介频特性较差,双层复合薄膜的介电性能较好,其介电常数εr为1078,其介电损耗tgδ较大,约为0.43.此外,对复合薄膜的磁滞回线测试表明:两种复合薄膜中均存在磁学性能,且双层结构复合薄膜的铁磁性能较大,其饱和磁化强度Ms为119 emu/cm3,剩余磁化强度Mr达到31.6 emu/cm3,矫顽场Hc为1360 Oe. 以上测试结果表明,铁电有序和磁有序可以存在于钙钛矿-尖晶石结构当中,通过多层复合和合适退火方式可以增强其铁电和介电性能. 相似文献
78.
《Electroanalysis》2017,29(5):1324-1331
Vanadium oxide/poly (3,4‐ ethylenedioxythiophene)(V2O5‐PEDOT) hybrid materials were prepared in a rotating quartz plasma reactor via capacitively coupled radio frequency (RF 13.56 MHz) plasma. Thin films of V2O5‐PEDOT hybrid and V2O5 were obtained by electron beam evaporation technique onto flexible PET substrate for electrochromic devices (ECDs) applications. As a counter electrode, both RF magnetron sputtered MoO3 onto ITO coated PET and only ITO coated PET electrodes were used. Characterizations of the films were carried out via using scanning electron microscopy‐energy dispersive X‐ray spectroscopy (SEM‐EDX) and X‐ray diffraction (XRD). Hybrid ECDs results showed that synergistic effect depending on improved stability between V2O5 and PEDOT. As a result, we developed all solid complementary electrochromic devices including V2O5, V2O5‐PEDOT and MoO3 films. The electrochromic device characteristics such as electrochromic contrast, coloration efficiency, switching time were calculated from optical and electrochemical measurements. The highest coloration efficiency and optical contrast were obtained as 53 cm2/C and 17 % for V2O5‐PEDOT/MoO3‐based ECD. 相似文献
79.
Peter Steinmann 《Fiber and Integrated Optics》2013,32(1):43-52
The costs of future local-distribution networks will be determined, for the most part, from the deployment and installation of the fiber-optic cable. The expenditure for the installation, which affects cost and time, can be minimized by utilizing techniques that allow simultaneous splicing of up to 12 single-mode fibers. The two main techniques employ the principles of direct fusing (butt welding) and of mechanical clamping in holding structures of very high geometrical precision. The various feasible methods are discussed and compared in detail. 相似文献
80.
Four modes of charge transfer interactions in polyaniline (PAN), viz. acid protonation, self-doping, charge transfer interactions with organic acceptors, and charge transfer interactions with surface grafted functional polymers have been studied by X-ray photoelectron spectroscopy (XPS). In the case of acid protonation, the protonation behavior of volatile and non-volatile acid differs. The structures of sulfonated leucomeraldine (LM) and nigraniline (NA) are similar to those of sulfonated and self-protonated emeraldine (EM). A substantially higher degree of charge transfer interaction with the organic acceptors is observed for EM film that has been subjected to one cycle of acid/base treatment. The charge transfer interactions with the organic acceptors have proceeded further than the pure formation of molecular complexes. Both pristine and Ar plasma or O3 pretreated EM films are susceptible to surface modifications by graft copolymerization. The protonic acid functional groups of the graft readily give rise to a self-protonated EM surface. 相似文献