共查询到20条相似文献,搜索用时 15 毫秒
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Luo H Wang H Bi Z Feldmann DM Wang Y Burrell AK McCleskey TM Bauer E Hawley ME Jia Q 《Journal of the American Chemical Society》2008,130(46):15224-15225
It is indispensable to use thin films for many technological applications. This is the first report of epitaxial growth of ternary nitride AMN2 films. Epitaxial tetragonal SrTiN2 films have been successfully prepared by a chemical solution approach, polymer-assisted deposition. The structural, electrical, and optical properties of the films are also investigated. 相似文献
3.
Nina V. Kaneva Georgi G. Yordanov Ceco D. Dushkin 《Reaction Kinetics and Catalysis Letters》2009,98(2):259-263
Nanostructured ZnO thin films were deposited on glass by the dip-coating sol–gel method. The films exhibited pronounced activity
to destroy malachite green in water both under UV-light illumination and in the dark. 相似文献
4.
Roberta Collino Joël Therasse Frédéric Chaput Jean-Pierre Boilot Yves Levy 《Journal of Sol-Gel Science and Technology》1996,7(1-2):81-85
In this work we investigated the biological properties of sol-gel films in aqueous medium. Functionalized silica films were prepared by the sol-gel process, from organically modified silicon alkoxides with amino or thiol groups. Covalent binding of proteins with different orientations according to the hydrophilic or hydrophobic character of the surface was studied. This binding occurred via a covalent coupling agent providing a very stable linkage. No denaturation was detected and a good detection of the antigen was observed. Immunoassays have demonstrated the biological activity of grafted antibodies. 相似文献
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Self-assembled poly(4-vinylpyridine)-grafted gold (Au) nanoparticles (NPs) and polystyrene-b-poly(4-vinylpyridine) block copolymers were fabricated by the introduction of a selective solvent to a common solution. The assembled mixtures were spin-coated onto solid substrates to fabricate composite gold/polymer thin films composed of copolymer-hybridized Au NPs and independent copolymer micelles. The obtained composite Au thin films had variable localized surface plasmon resonance (LSPR) bands and microscopic morphologies upon vapor annealing with selective solvents because the adsorption and dissolving of solvent molecules into the films could rearrange the copolymer block. The hybrid nanostructured Au thin films may have potential in vapor sensing and organic assays. 相似文献
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In this study, we use dipping and spinning methods to coat glass slides with sol-gel ZnO thin films, composed of zinc acetate dihydrate, monoethanolamine (MEA), de-ionized water and isopropanol. The effect of the annealing temperature on the structural morphology and optical properties of these films is investigated. These ZnO films were preheated at 275 °C for 10 min and annealed either at 350, 450 or 550 °C for 60 min. As-deposited films, formed by amorphous zinc oxide-acetate submicron particles, are transformed into a highly-oriented ZnO after thermal treatment. The surface morphology, phase structure and optical properties of the thin films were investigated by scanning electron microscopy, X-ray diffraction (XRD) and optical transmittance. Both techniques produced nanostructured ZnO thin films with well-defined orientation. The annealed films were transparent in the visible range with an absorption edge at about 375 nm and a transmittance of ca 85–90% with an average diameter of 40 nm. XRD results show the film was composed of polycrystalline wurtzite, with a preferential c-axis orientation of (002) and a single sharp XRD peak at 34.40, corresponding to the hexagonal ZnO. The grain size is increased by the annealing temperature. Both coating techniques create sol-gel ZnO films with the potential for application as transparent electrodes in optic and electronic devices. 相似文献
7.
噻菁染料的合成及吸收光谱的研究 总被引:1,自引:0,他引:1
合成了阳离子型、两性离子型和阴离子型的噻菁染料,对它们的结构进行了表征,并研究了染料的结构(阴离子和取代基的改变) 对吸收光谱的影响。 相似文献
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G. Q. Liu Z. G. Jin X. X. Liu T. Wang Z. F. Liu 《Journal of Sol-Gel Science and Technology》2007,41(1):49-55
Anatase TiO2 porous thin films were prepared on glass substrates by sol-gel method with Cetyltrimethylammonium Bromide (CTAB) as a pore-forming
agent, Tetrabutylorthotitanate as Ti precursor, ethanol as solvent and diethanolamine as chelating agent respectively. IR,
TG-DSC, XRD and SEM analyzed the chemical and physical changes during sol-gel process and characteristics of the films. Effects
of the amount of CTAB, alkane and water on morphology of the films were discussed and the principle of forming porous structure
was proposed. It was shown that the diameter of pores was changed in the range of 30–400 nm. 相似文献
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M. C. Santos A. J. Terezo V. C. Fernandes E. C. Pereira L. O. S. Bulhões 《Journal of Solid State Electrochemistry》2005,9(2):91-95
An electrochemical quartz crystal microbalance (EQCM) study of RuO2 thin films, prepared by the sol-gel precursor method, is presented. The X-ray diffraction (XRD) analysis demonstrates that RuO2 films were crystallized in the rutile phase and scanning electron microscopy investigations indicated the formation of a smooth surface. Cyclic voltammetry and EQCM studies were performed simultaneously in order to investigate the charging processes of the RuO2 films in 0.1 M HClO4. The voltammetric and mass versus potential responses present three well-defined regions associated with the RuO2 redox couples. Based on these results and on the mass-charge relationships, the corresponding charging mechanisms are proposed. In the potential region governed by the Ru3+/Ru4+ redox couple, the mass-charge relation can be associated with the double-injection of protons and electrons. The other regions correspond to water release and oxyhydroxide species formation during charging. 相似文献
10.
《Journal of membrane science》2001,185(1):105-124
Proton conductive membranes were prepared as thin films of about 10 μm thickness by an ion beam assisted plasma polymerization process. Argon ions were generated in a high frequency plasma and accelerated towards a PTFE target where CF fragments were released as a consequence of the ion impact. Various sulfur components (SO2, CF3SO3H or ClSO3H) were added to achieve proton conductivity by the formation of sulfonic acid groups. The CF fragments combined with the sulfur components to form a coherent thin film on a substrate. Mass spectrometric investigations revealed, however, that sulfur oxygen compounds were extremely delicate towards reduction to sulfur carbon compounds like CS2 or SCF2. The best membrane conductivities (>10−4 S/cm) and highest ion exchange capacities (0.15 mmol/g) were achieved with chlorosulfonic acid involved in the plasma polymerization process. Ultra-thin layers of these of these plasma polymers (ca. 300 nm) were subsequently deposited onto Nafion® membranes in order to suppress methanol permeation for a potential application in a direct methanol fuel cell (DMFC). The ratio of proton conductivity and methanol diffusion coefficient was employed for an assessment of the transport characteristics of the coated membrane. Diffusion coefficients were determined in a flow cell coupled to a mass spectrometer. The plasma polymer coating decreased both the methanol permeation and the proton conductivity. With a proton conductive plasma polymer coating the decrease of methanol diffusion could outweigh the loss of proton conductivity. Plasma coating offers a way to suppress methanol crossover in DMFCs and to maintaining the proton conductivity. 相似文献
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Li Gang Zhu Xuebin Lei Hechang Jiang Haifeng Song Wenhai Yang Zhaorong Dai Jianming Sun Yuping Pan Xu Dai Songyuan 《Journal of Sol-Gel Science and Technology》2010,53(3):641-646
CuAlO2 thin films were prepared on quartz glass and sapphire substrates by chemical solution deposition method using copper acetate
monohydrate, aluminum nitrate nonahydrate and 2-methoxyethanol as starting precursor and solvent. The effects of annealing
temperature on the structural, morphological, electrical and optical properties have been studied. Via the optimized annealing
treatment condition, CuAlO2 film annealed at 850 °C in nitrogen flow of 400sccm under atmosphere pressure exhibits the best performance with the lowest
room temperature resistivity of 3.6 × 102 Ω cm and the highest optical transmission in the visible region (>70% at around 600 nm wavelength). CuAl2O4 and CuO phases, not CuAlO2 phase are obtained when annealing temperature is lower than 850 °C. However, a further increase of annealing temperature
weakens the crystallization quality and deteriorates the surface morphology of CuAlO2 films as the annealing temperature exceeds 850 °C, leading to an increase in the resistivity and a decrease of the optical
transmission in the visible region of CuAlO2 films. 相似文献
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K. Joy 《Journal of Sol-Gel Science and Technology》2013,66(2):293-300
Ag doped ZrO2 thin films were deposited on quartz substrates by sol–gel dip coating technique. The effect of Ag doping on tetragonal to monoclinic phase transformation of ZrO2 at a lower temperature (500 °C) was investigated by X-ray diffraction. It is found that the Ag doping promotes the phase transformation. The phase transformation can be attributed to the increase in the tetragonal grain size and concentration of oxygen vacancies in the presence of the Ag dopant. Accumulation of the Ag atoms at the film surface and surface morphology changes in the films were observed by AFM as a function of varying Ag concentration. X-ray photoelectron spectroscopy gave Ag 3d and O 1s spectra on Ag doped thin film. The chemical states of Ag have been identified as the monovalent state of Ag+ ions in ZrO2. The Ag doped ZrO2 thin films demonstrated the tailoring of band gap values. It is also found that the intensity of room temperature photoluminescence spectra is suppressed with Ag doping. 相似文献
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《Solid State Sciences》2012,14(9):1282-1288
SnO2 thin films were deposited on glass substrates by using Successive Ionic Layer Adsorption and Reaction (SILAR) method at room temperature. The film thickness effect on characteristic parameters such as structural, morphological, optical and electrical properties of the films was studied. Also, the films were annealed in oxygen atmosphere (400 °C, 30 min) and characteristic parameters of the films were investigated. The X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) studies showed that all the films exhibited polycrystalline nature with tetragonal structure and were covered well on glass substrates. After the investigation of the crystalline and surface properties of the films, it was found that they were improving with increasing film thickness. Optical band gap decreased from 3.90 eV to 3.54 eV and electrical conductivity changed between 0.015–0.815 (Ω-cm)−1 as the film thickness increased from 215 to 490 nm. The refractive index (n), optical static and high frequency dielectric constants (ɛo, ɛ∞) values were calculated by using the optical band gap values as a function of the film thickness. 相似文献
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The monolayer assemblies incorporating the J-aggregates of oxacyanine dye, N,N'-dioctadecyloxacyanine perchlorate (S9), and thiacyanine dye, N,N'-dioctadecylthiacyanine perchlorate (S11), S9(J) + S11(J), have been fabricated by the Langmuir-Blodgett (LB) technique. The mole fraction X of S11, X = [S11]/([S9] + [S11]), was varied from 0 to 1. Steady-state absorption spectra, fluorescence spectra, and picosecond fluorescence decay curves of the monolayer assemblies have been measured. Spectroscopic properties of the monolayer assemblies incorporating the individual dye aggregates, S9 J-aggregate (S9(J), X = 0) or S11 J-aggregate (S11(J), X = 1), are characterized by a distinct J-band and resonance fluorescence at lambda(ab) = 403 nm and lambda(em) = 403 nm for S9(J) and lambda(ab) = 456 nm and lambda(em) = 463 nm for S11(J). On the other hand, absorption spectra of the S9(J) + S11(J) assemblies for X = 0.1-0.9 display two absorption bands, a shorter wavelength one and a longer wavelength one, whose peak positions are blue-shifted from those of the corresponding J-bands of the S9 J-aggregate and the S11 J-aggregate, respectively. Furthermore, fluorescence spectra are characterized by a single band (longer wavelength fluorescence) which is somewhat blue-shifted from the resonance fluorescence of the S11 J-aggregate. The fluorescence lifetimes of the S11 J-aggregate and isolated S11 molecules in LB films appear to be tau = 110 and 1900 ps, respectively, while the fluorescence lifetime of the longer wavelength fluorescence of the S9(J) + S11(J) assemblies takes practically a constant value of tau = 170-180 ps for X = 0.2-0.8. These observations would indicate that S9 and S11 molecules in the S9(J) + S11(J) assembly can form a specific mixed aggregate distinct from the individual S9 and S11 J-aggregates. From detailed considerations of the former works on luminescence properties of the S9 J-aggregate doped with isolated S11 molecules, as well as the mosaic-type mixed J-aggregate (M-aggregate) composed of a certain thiacyanine dye, 3,3'-disulfopropyl- 5,5'-dichlorothiacyanine sodium salt, and thiacarbocyanine dye, meso-substituted 3,3'-disulfopropyl-5,5'-dichlorothiacarbocyanine potassium salt, it is suggested that S9 and S11 can form a homogeneous aggregate of the persistence type (HP-aggregate). The HP-aggregate is distinguished from the M-aggregate because it is characterized by homogeneous mixing of two component dyes and persistence of two absorption bands. 相似文献
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T. Dhandayuthapani R. Sivakumar R. Ilangovan C. Gopalakrishnan C. Sanjeeviraja A. Sivanantharaja R. Hari Krishna 《Journal of Solid State Electrochemistry》2018,22(6):1825-1838
Anatase TiO2 thin films with high optical modulation, better reversibility, fast switching time, and enhanced coloration efficiency were prepared by nebulized spray pyrolysis technique. X-ray diffraction study confirmed the formation of anatase phase TiO2 in the present work. This inference was substantiated from the Raman active modes of A1g, 2 B1g, and 3 Eg corresponding to O–Ti–O bond in TiO2. The PL emission peak observed at 400 nm is corresponds to the indirect transition (X1b?→?Γ3) from the conduction band to the valence band. The average reflectance of TiO2 thin films was varied from 31 to 20%. The electrochemical study revealed the excellent performance of TiO2 films with high optical modulation (ΔT?=?61%), fast switching kinetics (t b ?=?1.6 s, t c ?=?2.4 s), good coloration efficiency (100 cm2 C?1), and better reversibility (86%). The efficient electrochromic behavior of films may be due to the smooth microstructure nature, which provides an easy pathway for the diffusion and charge transfer process of Li+ ions in TiO2 film matrix. The fast transfer of Li+ ion was realized from the electrochemical impedance spectroscopic measurement. 相似文献
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Remigijus Ivanauskas Vitalijus Janickis Vitalija Jasulaitienė 《Central European Journal of Chemistry》2013,11(4):636-643
Some earlier synthesized copper selenide (Cu x Se) layers formed on the surface of polyamide 6 by sorption-diffusion method using potassium selenotrithionate (K2SeS2O6) as precursor of selenium were characterized by the XRD, XPS and SEM methods. According to the results of the SEM studies, the most uniform Cu x Se layers form at the 2.5 h polyamide seleniumized duration at the temperature of 60°C. The thickness of layers, which dependeds on the duration of seleniumization, changed in the range of 0.8–3.2 µm. The XRD patterns of not previously studied Cu x Se layers showed their phase composition of six copper selenides: Cu2Se, two phases of CuSe2, Cu3Se2, berzellianite, Cu2-x Se, and bellidoite Cu2Se. Analysis of the XRD and XPS data shows that the macrostructure and composition of the CuxSe layers depend on the conditions of formation of these layers. 相似文献
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V. V. Shelkovnikov T. N. Gerasimova Z. M. Ivanova N. A. Orlova 《Russian Chemical Bulletin》1998,47(7):1306-1312
The formation of thin films of symmetrical and asymmetrical thiopyrylium dyes, containingtert-butyl substituents, on glass supports was studied. The films were deposited by centrifugation of solutions of individual
dyes or dye—polymer [poly(methyl methacrylate)] compositions. The dye: polymer ratios necessary for the formation of WORM
recording layers based on these dyes were determined. The use of a polymeric matrix increases the film thickness and optical
density but decreases its reflection power and does not allow crystallization of the dye on the support to be completely avoided.
An increase in the number oftert-butyl groups in the dye molecule prevents crystallization of the recording layer in the case of symmetrical dye molecules,
but does not prevent it for asymmetrical molecules. The data obtained were interpreted in terms of geometrical views on the
interaction of dye molecules in thin layers.
Translated fromIzestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1343–1349, July, 1998. 相似文献
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Structural information on thin Langmuir-Blodgett films of a charge transfer complex (N-docosylpyridinium TCNQ) is obtained by transmission and reflection electron diffraction. The data obtained complete the information supplied by other methods and cast a new light on some controversial points. In the precursor phase, the first layer has a specific structure in which TCNQ molecules with their faces normal to the substrate, display a long-range one-dimensional order. On subsequent layers, the TCNQ tend progressively to lie flat on the substrate, but in the conducting phase, the TCNQ molecules change their position again and are now upright on their shorter edge, grouped by pairs (dimers). To take into account all the reflections of the electron diffraction patterns obtained on the precursor phase, an original monoclinic cell is proposed with the parameters a = 13.85 Å, b = 14.65 Å, γ= 135°. An explanation of the 3D character of the layers on one hand and the partial disorder of the aliphatic chains on the outer surface on the other hand is suggested. The crystal size in the precursor phase depends particularly on the nature of the substrate and a tendency to epitaxial behaviour is detected. The structural results deduced from electron diffraction studies of the conducting phase are in good agreement with those obtained by X-rays. 相似文献