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本文合成了一种新型的两亲性酞菁分子,研究了它在不同溶剂中的聚集行为,考察了酞菁及酞菁与正十六烷混合的成膜性能,制备了混合的多层LB膜,并利用紫外光谱研究LB膜内的分子聚集状况,用分子激子理论对实验结果加以分析,还应用偏振紫外的方法对LB膜内酞菁分子大环的取向进行了确定。 相似文献
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酞菁化合物LB单分子膜的SERRS 总被引:4,自引:0,他引:4
酞菁类化合物具有优良的光电特性,选择适当的取代侧链可得到稳定的LB成膜材料,可望在微电子器件等方面获得重要的应用.本工作观测了四-4-(2,4-二特戊基苯氧基)酞菁铜(CuPc(Dt-PP)_4)在银岛膜上的LB单分子层的表面增强共振拉曼散射(SERRS)光谱。比较其固体粉末的共振拉曼散射(RRS)光谱,讨论了酞菁铜分子大环在载片表面的取向及其可能的原因。1 实验CuPc(Dt-PP)_4样品由陈文启等合成,经元素分析、IR、NMR、色谱等研究确认其结构如图1所示.银岛膜用真空蒸镀法制备在玻璃载片上。用同时蒸镀在铜网上的银膜的透射电 相似文献
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一个对称萘酞菁的LB膜及其二阶非线性光学性质的研究 总被引:1,自引:0,他引:1
用水平提拉法制备了四叔丁基萘酞菁锌的LB膜。利用表面压-面积曲线、紫外-可见吸收光谱、小角X-射线衍射等表征了LB膜的结构,结果表明该化合物可以形成较高质量的具有很好层状结构的多层LB膜,在膜中分子大环平面垂直于基片平面并且以分子平面并不完全重合的H-聚集体存在。采用透射SHG方法测量了相应LB膜的二阶非线性光学性质,结果显示在实验条件下该化合物LB膜的宏观二阶非线性系数以及分子超极化率分别为X 相似文献
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酞菁铜衍生物作为LB膜材料具有良好的热稳定性,与衬底的附着力强,有丰富的光电特性,并对NH_3有较高的气敏特性,本文应用透射电子显微镜研究了2种新型酞菁铜衍生物LB膜成膜过程的结构变化。 相似文献
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利用LB技术研究了带有4个长碳氢链的酞菁铜化合物(CuC12Pc)的单分子膜及它与十八胺(ODA)、二十酸(AA)的混合LB膜的聚集结构形态. 结果表明这种酞菁铜化合物在气液界面上可以形成比较稳定有序的双层Langmuir膜, 且可以转移质量较好的多层LB膜. 利用原子力显微镜(AFM)研究了酞菁铜分子的聚集体结构, 发现CuC12Pc/AA混合膜表现为网状的聚集结构, 而CuC12Pc/ODA混合膜形成长岛颗粒状聚集, 并结合UV-Vis吸收光谱讨论了酞菁铜分子形成不同聚集结构的原因. 相似文献
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Djaoued Y. Badilescu Simona Ashrit P.V. Bersani D. Lottici P.P. Brüning R. 《Journal of Sol-Gel Science and Technology》2002,24(3):247-254
TiO2 nanocrystalline thin films with varying degree of porosity have been prepared using a low temperature method. TiO2 films of the anatase form have been obtained by using a polyethylene glycol (PEG) modified sol-gel method. Densification and crystallization of the films was found to result from the thermal treatment of the dip coated films in boiling water. The films have been characterized by Raman, XRD, FTIR, AFM and optical methods. Highly transparent films with transmission in excess of 85% and porosity as high as 58% are formed predominantly of anatase crystallites of dimensions of the order of 5 nm. Initial results on lithium intercalation into these films resulting in an efficient optical modulation in the visible and near infrared regions demonstrate a good potential of these films for electrochromic applications. 相似文献
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Giulia Infurna Giuseppe Cavallaro Giuseppe Lazzara Stefana Milioto Nadka Tzankova Dintcheva 《Molecules (Basel, Switzerland)》2021,26(11)
In the last two decades, the naturally occurring polysaccharides, such as chitosan and pectin, have gained great attention having potential applications in different sectors, from biomedical to new generation packaging. Currently, the chitosan and pectic have been proposed as suitable materials also for the formulation of films and coatings for cultural heritage protection, as well as packaging films. Therefore, the formulation of biopolymer films, considering only naturally occurring polymers and additives, is a current challenging trend. This work reports on the formulation of chitosan (CS), pectin (PC), and chitosan:pectin (CS:PC) films, also containing natural crosslinking and reinforcement agents, such as citric acid (CA) and halloysite nanotubes (HNT), through the solvent casting technique. The produced films are characterized through water contact angle measurements, infrared and UV–visible spectroscopy and tensile test, while the durability of the CS:PC films is evaluated subjecting the film to accelerated UVB exposure and monitoring the photo-oxidation degradation in time though infrared spectroscopy. All obtained results suggest that both crosslinking and reinforcement agents have beneficial effects on the wettability, rigidity, and photo-oxidation resistance of biopolymer films. Therefore, these biopolymer films, also containing naturally occurring additives, have good properties and performance and they are suitable as coverage films for cultural heritage protection. 相似文献
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Deb S Hussain SA Biswas S Bhattacharjee D 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2007,68(2):257-262
Langmuir-Blodgett (LB) films at different mole fractions of p-terphenyl have been prepared using two different matrices, viz., stearic acid (SA) and polymethyl methacrylate (PMMA). Multilayered LB films have been formed by changing various LB parameters namely, mole fraction of mixing, changing the number of layers as well as also the different surface pressure of lifting. The spectroscopic characteristics of mixed LB films, solution and microcrystal have been compared using UV-vis absorption and steady state fluorescence spectroscopy. Change of planarity of TP molecules are occurred while going from solution to solid states/films. Fluorescence spectra of the mixed LB films reveal intense excimeric emission in the mixed LB films with D1 excimer peak at 397 nm and D2 excimer peak at 412 nm. Various LB parameters namely changing the number of layers as well as the different surface pressure of lifting played important roles in the formation of dual excimeric sites in the mixed LB films. 相似文献
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聚吡咯具有较高的电导率与良好的环境稳定性,被视为继聚苯胺之后最有工业化应用前景的导电高分子材料之一。聚吡咯与常规聚合物基体如聚乙烯醇、聚氯乙烯等形成的复合膜不仅可以综合聚吡咯奇异的多功能性与常规聚合物的易成膜性和低成本性于一体,而且可望发挥两者的协同效应,从而大大拓宽其应用领域。该研究已经成为导电聚合物研究领域中的又一新热点。作者系统论述了制备这类功能复合膜的两种典型制备方法,并在分析各自特点的基础上提出了改进与发展方向,指出聚吡咯复合膜具有广泛可调的电导率、快速的电学响应性以及稳定的电致变色性等多种功能,在透明导电膜、化学传感器、生物分离膜、电致变色膜领域具有诱人的应用前景。 相似文献
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Agrawal VV Mahalakshmi P Kulkarni GU Rao CN 《Langmuir : the ACS journal of surfaces and colloids》2006,22(4):1846-1851
By the reaction of the appropriate organometallic precursors and tetrakishydroxymethyl phosphonium chloride (THPC) at the toluene-water interface, we have prepared nanocrystalline films of Au-Ag and Au-Cu alloys with a range of compositions. The films have been characterized by X-ray diffraction, electron microscopy, optical spectroscopy, and other techniques, besides compositional analysis. The particle size of the nanocrystals in the films varies with the composition. The surface plasmon band of the alloy films as well as of the organosols obtained by the disintegration of the films by the addition of an alkanethiol show the expected composition dependence. It has been possible to prepare the nanocrystalline films of a ternary Au-Ag-Cu alloy. 相似文献
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By utilizing surfactant aggregates as supramolecular templates, mesoporous and mesostructured silicas with highly ordered structures became available. The resulting mesoporous silicas are promising candidates to host various photo- and electro-active species along with catalytically active species, due to their large and controllable pore sizes, highly ordered pore arrangements with low dimensional geometries, and reactive surfaces. We have developed the rapid solvent evaporation method, which is a modified sol-gel process, for synthesizing the mesostructured silica-surfactant films as well as the mesoporous silica films. Supported thin films, self-standing films and bubbles of mesoporous silicas have been synthesized by the rapid solvent evaporation method. The microstructures of the films have also been successfully controlled by changing the synthetic conditions. Taking advantage of the ease of synthetic operation and the transparency and homogeneity of the resulting materials, we have been interested in the introduction of functional units into the mesostructured materials. This paper reports the synthesis of transparent films of titanium- and aluminum-containing nanoporous silicas to modify the surface properties (such as adsorptive and catalytic) of nanoporous silicas. The incorporation of Al led to the formation of cation exchange or acidic sites on the mesopore surface, as revealed by the cationic dye adsorption experiments. The photocatalytic reactions of the Ti-containing nanoporous silica films were also examined. 相似文献
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Tongjit Kidchob Luca Malfatti Filomena Serra Paolo Falcaro Stefano Enzo Plinio Innocenzi 《Journal of Sol-Gel Science and Technology》2007,42(1):89-93
Thin sol-gel hafnia films have been synthesised from HfCl4, the synthesis has revealed to be a simple route to fabrication of hafnia films with high transparency in the UV-visible
range. The films have been fired at different temperatures in air up to 1000°C and have been characterized by X-ray diffraction
and Fourier transform infrared spectroscopy. Infrared absorption spectra of hafnia films have allowed to follow the formation
of monoclinic crystalline phases together with XRD. Formation of monoclinic hafnia crystallites has been observed upon calcination
at temperatures higher than 600°C, as shown by infrared spectroscopy and XRD.
The optical transmission and the refractive index as a function of the temperature of firing have been characterized by UV-Visible
spectroscopy and spectroscopic ellipsometry. The hafnia films, after firing at 600°C, had a refractive index of 1.92 with
a thickness of around 70 nm. 相似文献
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A diethanolamine stabilized precursor sol has been utilized for studying the effect of sol aging and annealing temperature
on key properties of TiO2 films. X-ray diffraction investigations have shown increased crystallite size in the films as a function of both sol aging
and the thermal treatment. Fourier transform infrared studies have elucidated that cleavage of the bond involving diethanolamine
and the alkoxide in the films requires high temperature annealing treatment upon the use of aged sol for the deposition of
the films. Multiple step chronoamperometry has shown the ion storage capacity of the films increases as a function of sol
aging, with the highest extent of Li ion insertion being obtained for films produced from as-prepared and aged sols and subsequently
annealed at, 300 and 350 °C, respectively. Films with excellent optical quality were obtained. Ellipsometry revealed that
the refractive indices of the films vary from 1.67 to 2.02. The highest thickness obtained in these films was nearly 900 nm.
The bandgaps of the films for both direct and indirect transitions decreased as a function of precursor sol’s aging. In addition,
although the indirect bandgap values have shown a decrease with increasing annealing temperature, the direct bandgap values
reveal a slight increase as a function of annealing temperature. 相似文献
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Zhengtian Gu Peihui Liang Xiaolin Liu Weiqing Zhang Yueqin Le 《Journal of Sol-Gel Science and Technology》2000,18(2):159-166
Tin dioxide thin films prepared by sol-gel dip-coating method with ammonia treatment have been studied. By using X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy, detailed investigation on the structure and morphology of the films has shown the condensation of Sn-OH and the strengthening of gel network net through ammonia treatment, which leads to the improvement of the adhesion of the films. From the spectral transmission, angular distribution of reflectance and absorption spectrum, the optical properties of the ammonia treated films indicate that the ammonia treated films have a favorable optical performance, and the films are more suitable for acting as antireflective films than the heat-treated films. The ammonia treated films also exhibit higher conductivity compared with the non-treated films. 相似文献