排序方式: 共有34条查询结果,搜索用时 328 毫秒
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Lu C Wei F Wu N Huang L Zhao X Jiao X Luo C Cao W 《Langmuir : the ACS journal of surfaces and colloids》2004,20(3):974-977
A kind of hybrid multilayer film based on mercaptobenzoic acid-capped Au nanoparticles (MBA-Au-NPs) and photoreactive nitrodiazoresin (NDR) has been fabricated via electrostatic self-assembly. Upon exposure to UV light, the initial ionic bonds between the layers of the film convert into covalent bonds and the film stability toward polar solvents, salt, or surfactant solutions increases significantly. The micropatterned NDR/MBA-Au-NP film with the covalently linked architecture was formed by selecting exposure of the film through a photomask and later developed in sodium dodecyl sulfate (SDS) aqueous solution. The metallic Au-NP micropatterns, furthermore, are produced by sintering the micropatterned NDR/MBA-Au-NP film at 550 degrees C, at which the organic components are removed completely. The well-defined micropatterns were characterized with atomic force microscopy (AFM), field emission scanning electron microscopy (FE-SEM), microscope with a charge-coupled device (CCD) camera, and X-ray photoelectron spectroscopy (XPS). 相似文献
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In this paper,the reliability of a parallel stress-strength model of exponentiated Pareto distribution is discussed.Different point estimations and interval estimations are proposed.The point estimators obtained are maximum likelihood and Bayesian estimators.The interval estimations obtained are approximate,exact,bootstrap-p and bootstrap-t confidence intervals and Bayesian credible interval.Different methods and the corresponding confidence intervals are demonstrated using some simulation studies. 相似文献
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Yang Y Zhang J Zhou C Wu S Xu S Liu W Han H Chen B Zhao XZ 《The journal of physical chemistry. B》2008,112(21):6594-6602
The effect of lithium iodide concentration on the conduction behavior of poly(ethylene oxide)-poly(vinylidene fluoride) (PEO-PVDF) polymer-blend electrolyte and the corresponding performance of the dye-sensitized solar cell (DSSC) were studied. The conduction behavior of these electrolytes was investigated with varying LiI concentration (10-60 wt % in polymer blend) by impedance spectroscopy. A "polymer-in-salt" like conduction behavior has been observed in the high salt concentration region. The transition from "salt-in-polymer" to "polymer-in-salt" conduction behavior happened at the salt content of 23.4 wt %, which is much lower than 50 wt % as generally reported. The electrolyte shows the highest ionic conductivity (approximately 10(-3) S cm(-1)) at the salt concentration above 23.4 wt %. From the evaluation of salt effect on the performances of corresponding DSSC, we find that increasing LiI concentration leads to increased short-circuit photocurrent density (Jsc) caused by enhanced I3(-) diffusion up to an LiI content of 28.9 wt %. Above this limitation, the Jsc decreases as a result of increased charge recombination caused by the further increased I3(-) concentration. The open-circuit voltage (Voc) increases gradually with LiI concentration owing to the enhanced I(-) content in DSSC. The optimized conversion efficiency is obtained at a salt content of 28.9 wt % in the "polymer-in-salt" region, with high ionic conductivity (1.06 x 10(-3) S cm(-1)). Based on these facts, we suggest that the changes of conduction behavior and the changes of I3(-) and I(-) concentrations in the electrolytes contribute to the final performance variation of the corresponding DSSC with varying LiI concentration. 相似文献
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A facile approach to fabricate hierarchically structured poly(3‐hexylthiophene‐2,5‐diyl) films 下载免费PDF全文
Weihua Zhang Chuanyong Zong Jixun Xie Juanjuan Wang Haipeng Ji Conghua Lu Hongfei Li Jens Wenzel Andreasen Shichun Jiang 《Journal of Polymer Science.Polymer Physics》2017,55(12):928-939
Microstructured surfaces have great potentials to improve the performances and efficiency of optoelectronic devices. In this work, a simple robust approach based on surface instabilities was presented to fabricate poly(3‐hexylthiophene‐2,5‐diyl) (P3HT) films with ridge‐like/wrinkled composite microstructures. Namely, the hierarchically patterned films were prepared by spin coating the P3HT/tetrahydrofuran (THF) solution on a polydimethylsiloxane (PDMS) substrate to form stable ridge‐like structures, followed by solvent vapor swelling to create surface wrinkles with the orientation guided by the ridge‐like structures. During spin coating of the P3HT/THF solution, the ridge‐like structures were generated by the in‐situ template of the THF swelling‐induced creasing structures on the PDMS substrate. To our knowledge, it is the first report that the creasing structures are used as a recoverable template for patterning films. The crease‐templated ridge‐like structures were well modulated by the THF swelling time, the modulus of the PDMS substrate, the P3HT/THF solution concentration and the selective/blanket exposure of the PDMS substrate to O2 plasma. UV–vis and fluorescence spectrometry measurements indicated that the light absorption and fluorescent emission were improved on the hierarchically patterned P3HT films, which can be utilized to enhance the efficiencies of organic solar cells. Furthermore, this simple versatile method based on the solvent swelling‐induced crease as the in‐situ recoverable template has been extended to pattern other spin‐coated films with different compositions. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017 , 55, 928–939 相似文献
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Jixun Xie Chuanyong Zong Xue Han Haipeng Ji Juanjuan Wang Xiu Yang Conghua Lu 《Macromolecular rapid communications》2016,37(7):637-642
Here the redox‐driven switch between the wrinkled and dewrinkled states on polyaniline (PANI) film is reported. This switch is derived from the reversible transition in different intrinsic redox states of polyaniline (e.g., between emeraldine salt (ES) and leucoemeraldine base (LEB) or between ES and pernigraniline base (PB)) that are involved in the redox reaction, coupled with the corresponding volume expansion/shrinkage. Interestingly, the as‐wrinkled ES film becomes deswollen and dewrinkled when reduced to the LEB state or oxidized to the PB state. Conversely, oxidation of the LEB film or reduction of the PB film into the swollen ES film leads to the reoccurrence of surface wrinkling. Furthermore, the reducibility of the dewrinkled LEB film and the oxidizability of the dewrinkled PB film are well utilized respectively to yield various wrinkled PANI‐based composite films.
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Chuanyong Zong Yan Zhao Haipeng Ji Jixun Xie Xue Han Juanjuan Wang Yanping Cao Conghua Lu Hongfei Li Shichun Jiang 《Macromolecular rapid communications》2016,37(15):1288-1294
Here, a simple combined strategy of surface wrinkling with visible light irradiation to fabricate well tunable hierarchical surface patterns on azo‐containing multilayer films is reported. The key to tailor surface patterns is to introduce a photosensitive poly(disperse orange 3) intermediate layer into the film/substrate wrinkling system, in which the modulus decrease is induced by the reversible photoisomerization. The existence of a photoinert top layer prevents the photoisomerization‐induced stress release in the intermediate layer to some extent. Consequently, the as‐formed wrinkling patterns can be modulated over a large area by light irradiation. Interestingly, in the case of selective exposure, the wrinkle wavelength in the exposed region decreases, while the wrinkles in the unexposed region are evolved into highly oriented wrinkles with the orientation perpendicular to the exposed/unexposed boundary. Compared with traditional single layer‐based film/substrate systems, the multilayer system consisting of the photosensitive intermediate layer offers unprecedented advantages in the patterning controllability/universality. As demonstrated here, this simple and versatile strategy can be conveniently extended to functional multilayer systems for the creation of prescribed hierarchical surface patterns with optically tailored microstructures.
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Tuning and Erasing Surface Wrinkles by Reversible Visible‐Light‐Induced Photoisomerization 下载免费PDF全文
Chuanyong Zong Yan Zhao Haipeng Ji Xue Han Jixun Xie Juanjuan Wang Prof. Yanping Cao Prof. Shichun Jiang Prof. Conghua Lu 《Angewandte Chemie (International ed. in English)》2016,55(12):3931-3935
Periodic wrinkling across different scales has received considerable attention because it not only represents structure failure but also finds wide applications. How to prevent wrinkling or create desired wrinkling patterns is non‐trivial because the dynamic evolution of wrinkles is a highly nonlinear problem. Herein, we report a simple yet powerful method to dynamically tune and/or erase wrinkling patterns with visible light. The light‐induced photoisomerization of azobenzene units in azopolymer films leads to stress release and consequently to the erasure of the wrinkles. The wrinkles in unexposed regions are also affected and oriented perpendicular to the exposed boundary during the stress reorganization. Theoretical models were developed to understand the dynamics of the reversible photoisomerization‐induced wrinkle evolution. This method can be applied for designing functional materials/devices, for example, for the reversible optical writing/erasure of information as demonstrated here. 相似文献
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In this paper, we study the two-parameter maximum likelihood estimation (MLE)problem for the GE distribution with consideration of interval data. In the presence of interval data, the analytical forms for the restricted MLE of the parameters of GE distribution do not exist. Since interval data is kind of incomplete data, the EM algorithm can be applied to compute the MLEs of the parameters. However the EM algorithm could be less effective.To improve effectiveness, an equivalent lifetime method is employed. The two methods are discussed via simulation studies. 相似文献