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1.
Yusuf Mülazim Memet Vezir Kahraman Nilhan Kayaman Apohan 《Journal of Sol-Gel Science and Technology》2011,59(3):613-620
10B containing organic–inorganic hybrid coating material based on a UV-curable formulation was prepared via anhydrous sol–gel
technique. UV curable coatings were applied on Plexiglas (PMMA) substrates. The molecular structure of the coating material
was analyzed by ATR-FTIR spectroscopy technique. The characterization of the UV-curable coating was evaluated by various techniques
such as gel content, abrasion resistance, chemical resistance, pencil hardness, pendulum hardness, MEK rubbing test, contact
angle, cross-cut test, gloss, transmittance test, neutron absorption, Limiting Oxygen Index and stress–strain tests. Hybrid
coatings showed a significant enhancement in radiation shielding properties. The thermal behavior of coatings was also evaluated.
It is observed that the thermal stability of coatings mainly depends on their boron and silicate contents. Results of all
analysis conducted on hybrid films, and coatings were discussed. 相似文献
2.
Hybrid organic–inorganic nanocomposite coatings were prepared by copolymerizing tetraethylorthosilicate with ethyltriethoxysilane
with an acid catalysis process. Oxygen sensor coatings were fabricated by doping the hybrid sol with platinum meso-tetra(pentfluorophenyl)
porphyrin. Photophysical properties and oxygen sensitivity of the sensor coatings were studied. The microstructure of the
coatings was examined using optical microscopy and scanning electron microscopy. The effect of sol–gel process conditions
like precursor silane molar ratio, acid concentration and stirring time of the sol on the oxygen sensitivity and surface microstructure
of the sensor coating was studied. Oxygen sensitivity and surface morphology of the coatings were dependent on the sol–gel
process parameters. 相似文献
3.
M. Laleh Farzad Kargar A. Sabour Rouhaghdam 《Journal of Sol-Gel Science and Technology》2011,59(2):297-303
Although magnesium is used in many industries, it is reactive and requires protection against aggressive environments. In
this study, oxide coating was formed on AZ91D magnesium alloy using micro-arc oxidation (MAO) process in an alkaline electrolyte.
Then, in order to seal the pores in the oxide film, a sol–gel layer was applied to the surface of the MAO coating by dipping.
For investigation of heat treatment temperature of the sol–gel layer on the properties of the coatings, two different temperatures
(150 and 350 °C) were chosen. Surface morphologies and compositions of the coatings were analyzed by Scanning Electron Microscope
and X-ray Diffraction (XRD). Surface roughness of the coatings was also measured. The corrosion behavior of the coatings was
evaluated with Electrochemical Impedance Spectroscopy and potentiodynamic polarization tests in 3.5 wt%NaCl solution. The
porosity percent of the coatings was measured by potentiodynamic polarization tests results. It is found that the sol–gel
layers successfully cover the pores of the MAO coatings. The results of the corrosion tests show that the sol–gel layers significantly
increase the corrosion resistance of the substrate by reducing the percent of the porosity. The grain size measurements by
XRD analysis shows that the grain size of the sol–gel layer heated in 350 °C is about 50 nm. 相似文献
4.
Xinxiang Zhang Congrui Cao Bo Xiao Lianghong Yan Qinghua Zhang Bo Jiang 《Journal of Sol-Gel Science and Technology》2010,53(1):79-84
A new modified antireflective coating was prepared by base catalyzed sol–gel process using tetraethylorthosilicate as precursor
and polyvinyl butyral as modifier. The properties of the silica sols and AR coatings were characterized with Fourier-transfer
infrared absorption spectroscopy, particle size analyzer, transmission electron microscope, programmable rheometer, UV–Vis
spectrophotometry, ellipsometry, atomic force microscope and contact angle measurement. It was found that addition of 4% PVB
greatly enhanced moisture-resistance of the AR coating. Optical transmittance of 4% PVB modified AR coating on BK7 substrate
was found to be nearly 100%. The water contact angles of normal and 4% PVB modified AR coating were 51 and 53°, respectively,
which indicates no significant increase of hydrophobicity of the modified coating. The peak transmittance of 4% PVB modified
AR coating was almost unaffected after being exposed to the moist surroundings while that of normal silica coating decreased
sharply from 99.8 to 96.5% within 2 weeks. The excellent moisture-resistance of PVB modified AR coating may be attributed
to the adsorption of PVB on the surface of AR coating. 相似文献
5.
Producing bioactive hydroxyapatite coatings on metallic implant materials combines the mechanical advantages of implant materials
and biological affinity of the hydroxyapatite surface to the natural tissue. In this work, hydroxyapatite was synthesized
on 316L stainless steel substrates via sol–gel method by using Ca(NO3)2·4H2O and C6H15O3P. In order to improve adherence of the coatings produced, the surface of the substrate was initially modified by electrodepositing
nucleus of calcium phosphate compounds. Effect of aging time for preparation of the sol solution and coating characteristics
were investigated. The phase compositions and structures of the coatings were characterized by X-ray diffractometry, and scanning
electron microscopy was used to determine morphological characteristics of the coatings. Adhesion between the hydroxyapatite
coating and the substrate was investigated by using scanning scratch tester. The coating produced on the modified surface
by the sol solution aged for 24 h was found to prove better morphological and adhesion properties. 相似文献
6.
O. Culha M. F. Ebeoglugil I. Birlik E. Celik M. Toparli 《Journal of Sol-Gel Science and Technology》2009,51(1):32-41
In this study, synthesis and characterization of semiconductor tin oxide (SnO2) thin films on glass substrate were systematically investigated by using sol–gel technique for gas sensing applications.
Turbidity, pH values, wettability and rheological properties of solution were measured by turbidimeter, pH meter, contact
angle goniometer and rheometer machines before coating process. The thermal, structural, microstructural and optical properties
of the coatings and powders made from the sols were extensively characterized by using DTA-TG, FT-IR, XRD, SEM-EDS, refractometer
and spectrophotometer. Four different solutions, including 6, 8, 10 and 14 mL methanol content, were prepared by sol–gel technique
to determine solvent influence on microstructure and semiconducting properties of the thin films. Refractive indiceses, band
gaps, absorbance and transmittance values of SnO2 thin films, containing different methanol quantity, were determined and their variations depending on solvent content were
obtained. It is concluded that solvent content influences microstructural and semiconducting properties of Sn based oxide
thin films notably. 相似文献
7.
Yong Wan Baojian Sun Weimin Liu Caixia Qi 《Journal of Sol-Gel Science and Technology》2012,61(3):558-564
In this paper, the coatings with friction-reducing properties were investigated using both sol–gel and self-assembling techniques.
The thin film of TiO2 was firstly prepared on glass substrates via a sol–gel method, followed by calcinating at 480 °C. The films of fatty acid
were then deposited on the TiO2 surface to obtain a dual-layer film. The contact angle measurement and FT IR spectroscopy were used to determine the wetting
behavior and chemical structure of films, respectively. The friction-reducing behavior of films sliding against a steel ball
was examined on a macro friction and wear tester. It is found that fatty acid is strongly adsorbed on sol–gel derived TiO2 surface. Good friction-reducing behavior is observed for the glass substrate after duplex surface-modification with TiO2 surface obtained by sol–gel method and top layer of fatty acid. 相似文献
8.
Wan Aini Wan Ibrahim Wan Norfazilah Wan Ismail Aemi Syazwani Abdul Keyon Mohd Marsin Sanagi 《Journal of Sol-Gel Science and Technology》2011,58(3):602-611
A new tetraethoxysilane-polydimethylsiloxane (TEOS-PDMS) for use as sorbent of stir bar sorptive extraction (SBSE) towards
two selected organophosphorus pesticides (OPPs) namely chlorpyrifos and malathion was successfully synthesized through sol–gel
technology. Four different molar ratios of TEOS:PDMS (1:1, 2:1, 3:1 and 4:1) sol solutions were prepared and dipped coated
onto the surface of a glass-encased stir bar. Extraction efficiency of the prepared coatings towards the two selected OPPs
were compared. A number of factors have been found to greatly affect the characteristics and properties of a particular sol–gel
coating. Hence, in this study, several sol–gel coating conditions have been optimized using the optimized molar ratio 3:1
TEOS:PDMS to obtain the best coating as the stationary phase for SBSE. The raw OH-TPDMS and TEOS were characterized using
Fourier Transform Infrared Spectroscopy (FT-IR) and compared with spectra of the four different molar ratios of TEOS:PDMS.
The FT-IR spectrum of TEOS:PDMS showed the co-polymerization between PDMS and hydrolyzed TEOS molecules demonstrating the
formation of the hybrid network in the sol–gel hybrid material. Surface morphology of hybrid sol–gel TEOS-PDMS with optimized
molar ratio of 3:1 TEOS:PDMS were examined using FE-SEM. The surface of the sol–gel coating seems to be rough and homogeneous.
The more rough structure formed by the 3:1 molar ratio TEOS:PDMS provides enhanced surface area which in turn improved sample
capacity or adsorption process. 相似文献
9.
Yong Wan Wenliu Chao Yifang Liu Junyan Zhang 《Journal of Sol-Gel Science and Technology》2011,57(2):193-197
This paper explores the possibility of making coatings with super friction-reducing and wear protection properties by using
both sol–gel and self-assembling techniques. The thin film of TiO2 was firstly prepared on glass substrates via a sol–gel method, followed by sintering at 480°C. The self-assembled monolayer
of Fluoroalkylsilane (FAS) were then prepared on TiO2 thin film to obtain TiO2–FAS dual-layer film. The contact angle measurement and X-ray photoelectron spectroscopy were used to determine the wetting
behavior and chemical structure of films, respectively. The friction behavior of films sliding against a steel ball was examined
on a macro friction and wear tester. It is shown that FAS is strongly adsorbed on sol–gel derived TiO2 thin film, making it strongly hydrophobic. Good friction-reducing and wear protection behavior is observed for the glass
substrate after duplex surface-modification with sol–gel TiO2 and top layer of FAS. 相似文献
10.
Preparation and characterization of TiO<Subscript>2</Subscript> sol–gel modified nanocomposite films
In this study, the role of TiO2 MT-150A loading in the polymeric sol was investigated for the synthesis of immobilized TiO2 nanocomposite films on glass substrate using the MT-150A nanoparticles-modified sol–gel method. The nanocomposite film properties
were examined using different material characterization techniques including X-ray diffraction, X-ray photoelectron spectroscopy,
field emission scanning electron microscopy, UV–Vis spectrophotometer, Scotch tape test and pencil hardness test. The hydrophilicity
of films during UV/Vis irradiation and storage in a dark place were evaluated by a contact angle analyzer. The MT-150A loading
had a significant effect on the amount of crystallite phases in the films. However, increasing the MT-150A loading in the
sol resulted in an increase in rutile phase content. In addition, increasing MT-150A loading in the sol yielded films with
higher hydrophilicity but a concentration of 10–30 g/L MT-150A in the sol was found as the maximum for obtaining films with
good adherence on the glass substrate. 相似文献
11.
Quan Chen Jason Gim Hong Tan Shou Cang Shen Yu Chan Liu Wai Kiong Ng Xian Ting Zeng 《Journal of Sol-Gel Science and Technology》2007,44(2):125-131
AlOOH boehmite nanorods, synthesized by a solid-based process, were incorporated into a sol–gel coating in which GPTS was
used as a precursor. Transparent composite coatings with nanorod content up to 40 wt% were obtained by spin coating the sol–gel
mixture on glass substrates. Nanorods in the coating were found be aligned parallel to the substrate surface. Mechanical properties,
such as modulus and hardness of the nanorod filled coating, were slightly lower than coatings of the same composition but
filled with commercially available nanosized boehmite particles. However, crack toughness was greatly improved, as supported
by nanoindentation test results. The improvement in crack toughness was attributed to the high aspect ratio of the rigid nanorods,
in addition to the fact that the nanorods were aligned within the composite parallel to the surface. 相似文献
12.
Alumina coatings are a promising candidate for the protection of metals prone to high temperature corrosion. If applied via
sol–gel process, especially by using so called aqueous modified Yoldas-sols, the deposition is hardened by differences in
surface free energy of substrate and sol. In this paper the apparent surface properties of samples to be coated and sols were
examined by contact angle measurements, IR-spectroscopy and tensiometry. The results imply, after consideration of possible
uncertainties, the use of surface tension reducing 2-butanol already present during hydrolysis of the sols to obtain an easy
and successful coating process. 相似文献
13.
Using zinc acetate and cobalt acetate as raw materials, isopropanol as solvent, and monoethanolamine as stabilizer, photosensitive
Co-doped ZnO sol was prepared by chemical modification with benzoylacetone. Chelate rings of benzoylacetone with zinc ions
are formed in the Co-doped ZnO sol and corresponding gel films. Irradiation of the gel film by a UV lamp in air leads to decomposition
of the chelate ring. Selective irradiation followed by leaching and annealing gave rise to the formation of Co-doped ZnO fine
patterns. The Co-doped ZnO film prepared using the photosensitive sol–gel method had a wurtzite structure and showed room-temperature
ferromagnetic property. 相似文献
14.
Porous titania film is prepared by alkali treatment of NiTi alloy followed by soaking treatment in HCl solution. The benefit
of this porous titania film as an interlayer to improve adhesion and integrity of the sol–gel titania coating on NiTi alloy
substrate is evidenced by surface morphological observations. X-ray diffraction analyses indicate the formation of Ni4Ti3 phase in the matrix during heat treatment of the NiTi samples. X-ray photoelectron spectroscopy results indicate that the
titania coating with two dip-coating layers has completely covered the NaOH–HCl treated NiTi substrate, and potentiodynamic
polarization tests show that this titania coating provides good protection for the treated NiTi substrate in 0.9% NaCl solution.
Ultraviolet illumination can increase surface hydrophilicity of the NiTi samples by reducing contact angles from 60–80° to
20–10°. 相似文献
15.
Osaki Toshihiko Yamada Kiho Watari Koji Tajiri Koji Shima Saori Miki Takeshi Tai Yutaka 《Journal of Sol-Gel Science and Technology》2012,61(1):268-274
Alumina cryogels were synthesized from a colloidal boehmite sol through a sol–gel processing and subsequent freeze drying,
and thermal stability was examined by comparison to that of the corresponding xerogel, precipitate and commercial alumina.
N2 adsorption, X-ray powder diffraction and transmittance electron micrography observations revealed that the stability was
higher for the cryogel than for others in particular at temperatures above 1,000 °C. The higher stability was ascribed to
the fine and uniform primary particles with fibrous shapes formed by the sol–gel technique and furthermore to the suppression
of aggregation of the primary particles owing to the subsequent freeze drying. It was also found that aluminum sec-butoxide
employed as a precursor for the preparation of boehmite sol was preferable compared to aluminum iso-propoxide. 相似文献
16.
Nilhan Kayaman Apohan Sevim Karataş Buket Bilen Atilla Güngör 《Journal of Sol-Gel Science and Technology》2008,46(1):87-97
A series of UV-curable nanocomposite coating materials were prepared by sol–gel technique from tetraethoxysilane (TEOS), methacryloxypropyltrimethoxysilane
(MAPTMS) in the presence of urethane acrylate resin based on polyethylene glycol 400 (PEG400). The sol–gel precursor content
in the hybrid coatings was varied from 0 to 30 wt.%. In addition, acrylated phenylphosphine oxide oligomer (APPO) is replaced
with urethane acrylate resin in order to investigate its effect on the nanocomposite property. The physical and mechanical
properties such as; gel content, hardness, adhesion, gloss, impact strength as well as tensile strength were examined. Results
from these measurements showed that all the properties of the hybrid coatings improved effectively by gradual increase in
sol–gel precursor and APPO resin content. The real time infrared technique was used to follow the degree of acrylic double
bond conversion. The thermal stabilities of the UV-cured nanocomposites were investigated by thermogravimetric analysis. The
results revealed that the addition of sol–gel precursor and APPO oligomer into the organic network leads to an improvement
in the thermal and flame resistance properties of the hybrid materials. It was also determined that the APPO containing hybrid
coating with 20 wt.% silica content gave higher char yield than the coating without APPO. It is a desirable achievement to
improve simultaneously both the flame retardancy and mechanical properties of a protective coating. SEM studies indicated
that inorganic particles were dispersed homogenously through the organic matrix. The hybrids were nanocomposite. It was also
found that, incorporation of APPO resin might govern the silica organization and this leading to formation of nanofibrillar
structure. 相似文献
17.
Anti-corrosion silica coating was prepared via the sol–gel method for AZ91D magnesium alloy using tetraethoxysilane and methyltriethoxysilane
as precursors. Silica coating was deposited on fluorinated magnesium alloy substrates by dip coating. The surface morphology
of the silica coating was characterized by scanning electron microscope (SEM). The corrosion properties were studied by electrochemical
impedance measurements and polarisation technique in 3.5 wt% Sodium chloride solution. The results showed an improvement in
the corrosion performance from these coatings. A three-factor, three-level design of experiment (DOE) with response surface
methodology including a Box–Behnken design was run to evaluate the main and interaction effects of several independent formulation
variables, which included precursor ratios MTES/TEOS (X1), sintering temperature (X3) and sol dilution (X2) which measured the volume of the diluted sol divided by the initial volume of sol. The dependent variables included the
corrosion current derived from the polarisation curve (icor = Y1) and the coating resistance derived from the Nyquist curve (Rcoat = Y2). Optimizations were predicted to yield Y1 and Y2 values of 1.57018E–7A cm−2 and 14279 Ω cm2, when X1, X2, and X3 were 3.36, 1.52 and 222, respectively. 相似文献
18.
Xinxiang Zhang Yulu Zhang Haiping Ye Bo Xiao Lianghong Yan Haibing Lv Bo Jiang 《Journal of Sol-Gel Science and Technology》2011,58(1):340-344
Antireflective (AR) coatings at 351 nm with different thickness were designed and prepared by sol–gel process using tetraethylorthosilicate
as precursor and ammonia as catalyst. The parameters of these coatings, including film thickness and refractive index, were
calculated by optical formula and the coatings were prepared accordingly. Sol dilution method was used to adjust the film
thickness. The wavelengths of maximum transmission measured by UV–Vis spectrophotometer, were used to monitor the film thickness.
It was found that AR coatings with higher thickness possess better abrasion-resistance. Hydroxyl terminated polydimethylsiloxane
(PDMS) was added into pure silica sol to improve both the abrasion-resistance and moisture-resistance of AR coating. 相似文献
19.
Sol–gel derived silica antireflective (AR) coatings have been widely used as the optical components for high peak power laser
systems because of their excellent optical properties and high laser-induced damage thresholds. However, the sol–gel derived
coatings have a high surface area that is more susceptible to be contaminated by absorption of trace amounts of water vapor
and other volatile organic compounds from the environment. In this paper, the major approaches to fabricate contamination
resistant sol–gel derived silica AR coatings have been extensively reviewed. Different approaches, including solution-phase
and vapor-phase silanization, ammonia–water vapor treatment and fluorine modification have been discussed. The optical properties
and laser-induced damage thresholds of modified coatings have also been evaluated. The improved sol–gel AR coatings have been
shown to possess superior contamination resistance to work in vacuum systems compare to the traditional sol–gel AR coatings. 相似文献
20.
The InVO4 sol was obtained by a mild hydrothermal treatment (the precursor precipitation solution at 423 K, for 4 h). Novel visible-light
activated photocatalytic InVO4–TiO2 thin films were synthesized through a sol–gel dipping method from the composite sol, which was obtained by mixing the low
temperature InVO4 sol and TiO2 sol. The photocatalytic activities of the new InVO4–TiO2 thin films under visible light irradiation were investigated by the photocatalytic discoloration of methyl orange aqueous
solution. The thin films were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM)
and UV–Vis absorption spectroscopy (UV–Vis). The results revealed that the InVO4 doped thin films enhanced the methyl orange degradation rate under visible light irradiation, 3.0 wt% InVO4–TiO2 thin films reaching 80.1% after irradiated for 15 h. 相似文献