共查询到20条相似文献,搜索用时 0 毫秒
1.
Nadir Kiraz Ömer Kesmez Esin Burunkaya Leyla Budama Burçin Acar Meltem Asiltürk H. Erdem Çamurlu Ertuğrul Arpaç 《Journal of Sol-Gel Science and Technology》2010,56(3):227-235
This paper describes the preparation and characterization of glass films consisting of SiO2, Li2O, Na2O, K2O or MgO in varying compositions on stainless steel and aluminum substrates by sol–gel method. Silver phosphate or silver
incorporated zeolite was also introduced into the sols for obtaining antibacterial effect. The SiO2/Li2O/Na2O system having the composition of 85:5:10 wt% was found as the optimum for obtaining a stable sol and film formation. The
films were investigated by scanning electron microscopy (SEM) and electron dispersive analysis by X-ray (EDX), Fourier transformed
infrared (FTIR) spectroscopy, thermo-gravimetric analysis (TGA) and differential thermal analysis (DTA). Homogenous films
having 300 ± 20 nm thicknesses were formed by spin coating and then by curing at 500 °C for 1 h. Obtained films had high adherence
to the metal substrates and they were also durable in acidic, basic or NaCl environments. They also presented a powerful antibacterial
effect against E. coli. 相似文献
2.
Polycarbonate/epoxy/silica hybrid films were prepared by curing an epoxy reaction via in situ sol–gel process. The influence
of the synthetic conditions, such as the ratio of different epoxy reagents and the contents of [2-(3,4-epoxycyclohexyl)ethyl]trimethoxysilane
on the physical and optical properties of these hybrid films were investigated in details. The coefficient of thermal expansion,
surface roughness, and light transmittance at a wavelength range from 250 to 800 nm were measured. These excellent overall
performances make it a promising photonic packaging material. 相似文献
3.
Ana C. Marques Himanshu Jain Carol Kiely Kai Song Christopher J. Kiely Rui M. Almeida 《Journal of Sol-Gel Science and Technology》2009,51(1):42-47
Development of optimal scaffolds for bone tissue engineering and regeneration is still a challenge, since many materials and
structures have been proposed but few have reached clinical expectations. This work reports on the preparation and characterization
of SiO2-CaO and SiO2-CaO-P2O5 sol–gel derived monoliths, with potential application as glass scaffolds for bone regeneration, exhibiting a nano/macro trimodal
pore size distribution, including pores of ~100’s of micrometers (μm), several microns and just a few nanometers (nm) in size.
Interconnected macropores (~20–200 μm) have been obtained in the present work by polymerization-induced spinodal phase separation
along with the sol–gel transition, when a water soluble polymer [poly(ethylene oxide)] was added to the sol–gel solution;
the several-micron pores are spherical and isolated and might be the result of secondary phase separation by nucleation-growth
mechanism; the interconnected nanopore (~5–25 nm) structure of the macroporous gel skeleton, on the other hand, was tailored
by solvent exchange procedures. The morphological and textural characterization of these materials was performed by scanning
electron microscopy (SEM), transmission electron microscopy (TEM), X-ray ultra microscopy (XuM), nitrogen adsorption and mercury
intrusion porosimetry. The factors affecting the porosity exhibited by the scaffolds, such as glass composition and solvent
exchange conditions, have been assessed.
相似文献
Ana C. MarquesEmail: |
4.
Giancarlo R. Salazar-Banda Sandra R. Moraes Artur J. Motheo Sergio A. S. Machado 《Journal of Sol-Gel Science and Technology》2009,52(3):415-423
The development of efficient anti-corrosion and environmentally friendly coating systems are needed for the replacement of
the highly toxic Cr-based conversion coatings for corrosion protection of aluminum alloys. In this study, we demonstrate that
the direct application of ceramic cerium-based sol–gel coatings to AA7075-T6 substrates produces high-performance anti-corrosion
layers. Electrochemical experiments and analyses of the microstructure demonstrate that the protective layers are very efficient
for the passivation of the alloy surfaces operating as both passive and active barrier for corrosion protection. 相似文献
5.
6.
Ying Zhang Faming Gao Lihua Gao Li Hou Yufeng Jia 《Journal of Sol-Gel Science and Technology》2012,62(2):134-139
Antireflective coatings (ARCs) on tri-layer thin film stacks were studied in this paper. Silica sols have been prepared by
acid-catalyzed or base-catalyzed hydrolysis and condensation reactions of tetraethyl orthosilicate. Antireflective nanometric
SiO2/TiO2 films are formed on both sides of the glass substrates by combining the sol–gel method and the dip-coating technique. Seen
from the transmittance spectra of different films, a maximum light transmittance of 99.9% was obtained at the band of 300–800 nm.
Scanning electron microscope (SEM) and atomic force microscopy (AFM) confirm the well-covered surface morphology. By the SEM
observations we can see that the films are full of coverage on glass surface and containing no voids or cracks. The image
root mean square roughness of the two types of ARCs provided by the AFM is 1.21 and 3.04 nm, respectively. Furthermore, a
surface profiler was used to determine the thickness of each layer in the obtained multi-layer coating system. 相似文献
7.
Hasan Guleryuz Ingeborg Kaus Claudine Filiàtre Tor Grande Mari-Ann Einarsrud 《Journal of Sol-Gel Science and Technology》2010,54(2):249-257
Deposition of silica thin films on silicon wafer was investigated by in situ mass measurements with a microbalance configured
for dip coating. Mass change was recorded with respect to deposition time when the substrate was fully immersed in the silica
sol. Mass gain during deposition was higher than predicted from monolayer coverage of silica nano particles. This implied
that deposition was facilitated by gelling of the nanoparticles on the substrate. The rate of deposition was enhanced by increasing
the particle concentration in the sol and by decreasing the particle size from 12 to 5 nm. Increasing the salt concentration
of the silica sol at constant pH enhanced the deposition of the silica particles. Reducing the pH of the sol from 10 to 6
decreased the deposition rate due to aggregation of the primary silica particles. 相似文献
8.
9.
10.
K. Thongsuriwong P. Amornpitoksuk S. Suwanboon 《Journal of Sol-Gel Science and Technology》2012,62(3):304-312
Silver-doped ZnO thin films with various loadings of Ag in the range of 0–10 mol% were prepared by the sol–gel dip-coating
method. All prepared films show X-ray powder diffraction patterns that matched with ZnO in its würtzite structure. The grain
size decreased as the Ag loading increased. The prepared films, under UV blacklight illumination, produced a photocatalytic
degradation of methylene blue, rhodamine B and reactive orange solutions. Furthermore, they inhibited the growth of Escherichia
coli bacteria under UV blacklight irradiation and to a lesser extent in dark conditions. The photocatalytic and antibacterial
activities of the prepared films increased with Ag loading, presumably because Ag enhanced the efficiency of generation of
superoxide anion radicals (•O2
−) and hydroxyl radicals (•OH). 相似文献
11.
12.
Al-doped zinc oxide (AZO) films were prepared by a wet-chemical coating technique, their microstructure and crystal growth were characterized as a function of the single layer thickness. When similar final thicknesses are attained by more multiple subsequent coating-firing cycles, film porosity is reduced from over 14 to 2 %. Simultaneously the AZO crystallite size is increased from approximately 23 to 60 nm, a preferential c-axis oriented growth is observed. Different substrates (soda-lime glass, soda-lime glass with a SiO2 barrier coating, borosilicate glass and alkali-free display glass) were used and the resulting AZO films were compared. It is found that the substrate composition primarily affects grain growth and subsequently the electrical performance of the AZO films. 相似文献
13.
Effect of annealing temperature on the quality of Al-doped ZnO thin films prepared by sol–gel method
Lai Chi-ming Lin Keh-moh Rosmaidah Stella 《Journal of Sol-Gel Science and Technology》2012,61(1):249-257
The different thermal expansion coefficients and lattice mismatch between ZnO and Al may produce residual stress in Al-ZnO
(AZO) thin films. Annealing processes can be applied to modulate this residual stress. In this study, three different rapid
thermal annealing (RTA) temperatures (350, 450, and 600 °C) were applied to an AZO thin film, prepared using sol–gel method.
The mechanical properties, optical properties, and structure of the AZO thin film were investigated experimentally. The results
show that increasing the RTA temperature increased the Young’s modulus and hardness of the films. The grain size of the films
also increased with increasing RTA temperature. However, the film thickness and shear stress component decreased with increasing
RTA temperature. Both compressive and tensile stress decreased gradually with increasing film thickness after RTA treatment.
It was demonstrated that the use of a relatively high RTA temperature can effectively relax the residual stress in AZO thin
films. 相似文献
14.
15.
16.
Qing Ren Yuanyuan Zhang Ying Chen Genshui Wang Xianlin Dong Xiaodong Tang 《Journal of Sol-Gel Science and Technology》2013,67(1):170-174
La1?xSrxMnO3 (x = 0.33) (LSMO) thin films have been fabricated successfully by sol–gel method on two different types of substrates, Si (111) and SrTiO3 (STO) (001). Microstructure and magnetic properties of LSMO thin films have been investigated. The X-ray diffraction studies of the films confirm the pure phase of the LSMO thin films. In contrast with LSMO thin films on Si substrate, the performances of LSMO on STO substrate are superior both from structural and magnetic properties. For the samples deposited on STO substrate, highly preferred orientation as well as less strain and grain defects was found; in other aspect, the magnetization, the residual and saturation moment value, tended greater while a decreased coercive field required merely (saturation moment value was about five times and coercive field was only about 13 % of those on Si substrate). The Curie temperature of LSMO thin films on Si and STO substrates is estimated to be about 349.7 and 359 K, respectively. 相似文献
17.
Zanhong Deng Xiaodong Fang Suzhen Wu Weiwei Dong Jingzhen Shao Shimao Wang Man Lei 《Journal of Sol-Gel Science and Technology》2014,71(2):297-302
Single phase delafossite CuFeO2 thin films were synthesized by a simple sol–gel method. The influence of polyethylene glycol (PEG) on the morphology and optoelectronic properties of the films was studied by addition of 1.0 g PEG in 10 ml precursor solution. The crystal sizes of the derived CuFeO2 films with and without addition of PEG were 49 nm, but the sample with addition of PEG (labeled as CFO-PEG) showed weaker c-axis orientation growth. The sample without addition of PEG (labeled as CFO) showed a compact surface without detectable pores and had a thickness around 50 nm. However, the sample CFO-PEG exhibited a porous surface with worm-like grains in nanometric scale and had a thickness around 310 nm. Enhanced absorbance in UV–vis region was observed for the sample CFO-PEG which might ascribe to both the thickness and porous surface. The optical direct bandgaps at near-UV were estimated to be ~3.0 and 3.38 eV for the sample CFO-PEG and CFO, respectively. Though the porous surface of CFO-PEG has improved the absorbance in UV–vis region, the resistivity has also been increased due to the homogeneous distribution of interspaces between the worm-like grains, which makes the incident photon to current efficiency of CFO-PEG lower than that of CFO. 相似文献
18.
19.
20.
Yan-Feng Zhu Rong-Gui Du Wen Chen Hai-Qing Qi Chang-Jian Lin 《Electrochemistry communications》2010,12(11):1626-1629
A combined sol–gel and hydrothermal method was developed for preparing a three-dimensional titanate nanowire network film on titanium substrates to achieve an especial photocathodic protection effect for 403 stainless steel. Photopotential measurements were performed to study the protection effect of the film. The results indicated that the titanate film exhibited a special all-dimensional uniform porous structure composed of branched titanate nanowires. When we coupled the steel in a 0.5 M NaCl solution to the titanate film photoanode in a 1.0 M NaOH solution under illumination, its potential decreased by 560 mV. Especially after the light source was cut off, the photopotential of the steel increased by only 50–145 mV, and kept at the lower values than the corrosion potential under dark conditions for over 10 h, indicating that the titanate nanowire network film could produce a striking photocathodic protection effect for 403 stainless steel under illumination and dark conditions. 相似文献