共查询到20条相似文献,搜索用时 15 毫秒
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Quan Tan Gang Yu Yuan Liao Bonian Hu Xueyuan Zhang 《Colloid and polymer science》2014,292(12):3233-3241
In order to prepare the highly stable aqueous suspensions of antimony-doped tin oxide (ATO) used for the transparent and thermal insulation fluorocarbon coating, the effect of sodium polyacrylate (PAAS) and polyvinyl alcohol (PVA) on the stability of the suspensions was investigated. The stability and dispersity of the suspensions were characterized using zeta potential analyzer, ultraviolet–visible spectrophotometer, and scanning electron microscope. No sediments were observed after 6-month storage of the ATO suspensions containing 0.1 wt% PAAS and 2.0 wt% PVA. The reason why aqueous suspensions were capable of stabilization was explained from a theoretical perspective. A new model of steric hindrance for colloid particles stabilized by binary dispersant was proposed, which may have positive contribution to other colloid system containing two dispersants. A nano-composite fluorocarbon coating, exhibiting a good thermal insulation and high transmittance, was formed after ATO suspensions were added in fluorocarbon emulsion. The temperature inside the chamber was decreased by 6.0 °C, and 75.0 % visible light rays could pass through the coating. 相似文献
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Laser-induced fragmentation of indium tin oxide nanoparticles was performed in water by laser irradiation with various laser energies. Fragmentation of the nanoparticles proceeded with increased laser energy. The fragmented nanoparticles showed high transmittance in the visible region and lower transmittance in the ultraviolet and infrared regions. The optical band gap of the fragmented nanoparticles increased with decreasing average particle size. The increase of the band gap was possibly caused by the Burstein-Moss effect due to the increasing concentration of carriers generated by the surface defects of the oxygen vacancies on smaller nanoparticles. 相似文献
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Nursen Avci Philippe F. Smet Johan Lauwaert Henk Vrielinck Dirk Poelman 《Journal of Sol-Gel Science and Technology》2011,59(2):327-333
Clear aluminium oxide sols without precipitation were synthesized via a non-aqueous sol–gel technique using three different
alcohols (ethanol, isopropanol and n-butyl alcohol) as solvent, aluminium sec-butoxide as a precursor and acetyl acetone as
a chelating agent. Although all sols could be successfully used to prepare thin films, the most stable one was prepared with
n-butyl alcohol. Highly transparent, homogenous and amorphous aluminium oxide thin films were obtained on Si substrates after
a heat treatment at 500 °C. X-Ray photoelectron spectroscopy (XPS) and Fourier transform infrared absorption (FT-IR) spectroscopy
revealed all films were hydroxide free. The optical and structural properties of the films were particularly investigated.
Any significant difference except from thickness on the film properties was not observed by changing the alcohol. Refractive
index was used as an indication of the porosity of the films and ranged from 1.54 to 1.60. 相似文献
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S. A. Muhammed Ali Anwar Mustafa Raduwan Nor Fatina Muchtar Andanastuti Somalu Mahendra Rao 《Journal of Sol-Gel Science and Technology》2018,86(2):493-504
Journal of Sol-Gel Science and Technology - La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) is a perovskite-type oxide that exhibits excellent mixed ionic–electronic conducting properties and is a... 相似文献
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C. A. Kawaguti S. H. Pulcinelli C. V. Santilli A. F. Craievich 《Journal of Sol-Gel Science and Technology》2006,37(3):213-217
The surface properties of SnO2 nanoparticles were modified by grafting ionic (Tiron®, (OH)2C6H2(SO3Na)2·H2O) or non-ionic (Catechol®, C6H4-1,2-(OH)2) capping molecules during aqueous sol-gel processing to improve the redispersibility of powdered xerogel. The effect of the amount of grafted organic molecules on the redispersibility of powders in aqueous solution at several basic pH values was studied. The nanostructural features of the colloidal suspensions were analyzed by small angle X-ray scattering (SAXS) measurements. Irrespective of the nature and amount of grafted molecules, complete redispersion was obtained in aqueous solution at pH = 13. The redispersion at pH = 11 results in a mixture of dispersed primary particles and aggregates. The proportion of well dispersed nanoparticles and aggregates (and their average size) can be tuned by the quantity of grafted ionic molecules. 相似文献
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Kwan P Schmitt D Volosin AM McIntosh CL Seo DK Jones AK 《Chemical communications (Cambridge, England)》2011,47(45):12367-12369
Stable immobilization of two redox proteins, cytochrome c and azurin, in a thin film of highly mesoporous antimony-doped tin oxide is demonstrated via UV-vis spectroscopic and electrochemical investigation. 相似文献
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Zhe-Wei Chiu Yu-Jen Hsiao Te-Hua Fang Liang-Wen Ji 《Journal of Sol-Gel Science and Technology》2014,69(2):299-302
Europium-doped nanocrystals of lithium zinc vanadium oxide (LiZnVO4) prepared via the sol–gel method are characterized. The X-ray power diffraction results reveal that a pure phase is obtained at 500 °C. The photoluminescence spectra of LiZnVO4:xEu (x = 7 mol%) exhibit emission peaks at 526, 597 and 620 nm. The emission shifts from bluish-green to yellow when the doping concentration is increased from 0 to 7 mol%, due to the emission peak at 620 nm from the 5D0 → 7F2 transition, which originated from charge transfer transitions from VO4 3? to Eu3+ ions. 相似文献
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CO-sensing properties of undoped and doped tin oxide thin films prepared by electron beam evaporation 总被引:3,自引:0,他引:3
Undoped thin films of tin oxide and those doped with indium oxide and nickel oxides were deposited by electron beam evaporation. The effects of the film thickness and preparation conditions (films prepared with or without the presence of oxygen environment during deposition) on the optical and carbon monoxide sensing properties of the films were studied. The films were characterized using X-ray diffraction and X-ray photoelectron spectroscopy and optical spectroscopy techniques. All the films were found to be amorphous. It was found that the sensitivity of the films to CO increased with the thickness and the porosity of the films. It was found that their selectivity to CO gas relative to CO2 and SO2 gases could be improved upon doping the films with indium (or nickel) oxide. 相似文献
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Myrtil L Kahn Thierry Cardinal Bruno Bousquet Miguel Monge Véronique Jubera Bruno Chaudret 《Chemphyschem》2006,7(11):2392-2397
The emission properties of nanocrystalline ZnO particles prepared following an organometallic synthetic method are investigated. Spherical particles and nanorods are studied. The shape of the particles and the ligands used are shown to influence the luminescence properties in the visible domain. Two different emissions are observed at 440 nm (approximately 2.82 eV) and at 580 nm (approximately 2.14 eV) that are associated with the presence of surface defects on the particles. The first emission corresponds to the well-known yellow emission located at 580 nm (approximately 2.14 eV) with a lifetime of 1850 ns for 4.0 nm size ZnO nanoparticles. The second emission at 440 nm (approximately 2.82 eV) is observed when amine functions are present. This strong blue emission is associated with an excitation energy less than that associated with the yellow emission displaying a lifetime of nine nanoseconds. A possible hole trapping effect by the amine groups on the surface of the ZnO particles is discussed as the origin of this emission. The modification of the intensities between the two visible emissions for different particle shapes is proposed to be related to a specific location of the amine ligands on the surface of the particles. 相似文献
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Sikora M Adam D Korczyk PM Prodi-Schwab A Szymczak P Cieplak M 《Langmuir : the ACS journal of surfaces and colloids》2012,28(2):1523-1530
The analysis of the TEM images of indium tin oxide (ITO) clusters in ink solutions deposited from ink dispersions reveals that their geometry arises from a diffusion limited cluster aggregation (DLCA) process. We model films of ITO clusters as built through deposition of DLCA clusters made of primary spherical nanoparticles of 13 nm in diameter. The deposition is then followed by a further compactification process that imitates sintering. We determine the conductivity of the sintered films by mapping the problem to that of the resistor network in which the contact regions between the touching spheres provide the dominant electric resistance. For a given volume fraction, conductivity of the sintered films is shown to be larger than that for the randomly packed spheres. However, the larger a typical radius of gyration of the clusters the smaller the enhancement. We also provide numerical tests for the routines used in the interpretation of the TEM images. 相似文献
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Keh-moh Lin Po-chun Hsu Guan-ting Chen Yutaka Sawada 《Journal of Sol-Gel Science and Technology》2014,71(2):260-266
In this study, IZO/IGZO powders and films of different composition ratios were fabricated by sol–gel method. The influences of the composition ratio on the decomposition temperature, crystallization behavior, structural and optical properties of multi-component oxides were thoroughly examined. Thermogravimetric/differential scanning calorimetric results revealed that in contrast to zinc and indium oxides, the high crystallization temperature and low crystallinity of gallium oxide were attributed to the high dehydroxylation temperature of gallium hydroxide, which led to the high decomposition and crystallization temperatures of IGZO compound. The XRD analysis of the IGZO films confirmed that the addition of Ga amount made the films turn into amorphous easily. However, TEM analysis suggested that the IZO film (In:Zn = 1:2) and the IGZO (In:Ga:Zn = 1:1:1) film consisted of short-range-order nanostructure although the selected area diffraction of both samples indicated that they are amorphous. The transmittance measurements agreed well with the XRD results; that is, the band gaps of the IZO/IGZO films obviously depend on the composition ratio and are closely related to the change of the structural properties. 相似文献
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Sumalin Phokha Supree Pinitsoontorn Santi Maensiri Saroj Rujirawat 《Journal of Sol-Gel Science and Technology》2014,71(2):333-341
This work reports the study the structure, optical and magnetic properties of LaFeO3 nanoparticles synthesized by the polymerized complex method. The LaFeO3 nanoparticles were successfully obtained from calcination of the precursor at different temperatures from 750 to 1,050 °C in air for 2 h. The calcined LaFeO3 nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–Visible spectroscopy, X-ray photoelectron spectroscopy (XPS), X-ray absorption near edge spectroscopy (XANES) and vibrating sample magnetometry. The XRD and TEM results showed that all LaFeO3 samples had a single phase nature with the orthorhombic structure. The estimated crystallite sizes were in the range of 44.5 ± 2.4–74.1 ± 4.9 nm. UV–Vis spectra showed strong UV and Vis absorption with small band gap energy. The valence states of Fe ions were in the Fe3+ and Fe4+ state, as confirmed by XPS and XANES results. The weak ferromagnetic behavior with specific saturation magnetization of 0.1 emu/g at 10 kOe was obtained for the small particle of 44.5 ± 2.4 nm. The uncompensated spins at the surface was proposed as playing a part in the magnetic properties of small sized LaFeO3. 相似文献