Photostability and moisture uptake properties of wood veneers coated with a combination of thin sol-gel films and light stabilizers

Holzforschung ◽  
2011 ◽  
Vol 65 (2) ◽  
Author(s):  
Mandla A. Tshabalala ◽  
Ryan Libert ◽  
Christian M. Schaller
Keyword(s):  
Thin Film ◽  
Sol Gel ◽  
Organic Thin Films ◽  
Water Soluble ◽  
Moisture Uptake ◽  
Uv Absorber ◽  
Organic Light ◽  
Gel Film ◽  
Sol Gel Films ◽  
Wood Surfaces

Abstract In recent years, there has been increased interest in the use of inorganic UV blocking nanoparticles for photostabilization of wood surfaces. Photostability and moisture uptake properties of wood veneers coated with a combination of hybrid inorganic-organic thin sol-gel films and organic light stabilizers was investigated. The light stabilizers were applied by brushing, and the thin sol-gel films were deposi-ted on the wood surface by dipping in a sol prepared from a mixture of methyltrimethoxysilane, hexadecyltrimethoxysilane, and aluminum isopropoxide precursors. Although the sol-gel film improved the moisture resistance of the wood veneers, it showed mixed results on photostability. Under light and spray conditions in a Weather-Ometer™, specimens treated with a combination of sol-gel thin film and a UV absorber, tris-resorcinol triazine and an acrylic self-crosslink-ing binder, or treated with lignin stabilizer/tris-resorcinol triazine/acrylic self-crosslinking binder showed good overall weathering performance. Under permanent light conditions in the Weather-Ometer™, specimens treated with a combination of sol-gel thin film, a lignin stabilizer, and a water soluble UV absorber – namely: (2-hydroxyphenyl)-benzotriazole – revealed a good overall weathering performance. This study has demonstrated the feasibility of using a combination of organic light stabilizers and sol-gel deposits of hybrid inorganic-organic thin films to improve weathering resistance of softwood substrates.

Moisture absorption properties of hardwood veneers modified by a sol-gel process

Holzforschung ◽  
2017 ◽  
Vol 71 (7-8) ◽  
pp. 645-648 ◽  
Author(s):  
Edgars Kirilovs ◽  
Silvija Kukle ◽  
Janis Gravitis ◽  
Hans-Jörg Gusovius
Keyword(s):  
Thin Films ◽  
Moisture Absorption ◽  
Sol Gel ◽  
Organic Thin Films ◽  
Protective Agent ◽  
Moisture Uptake ◽  
Absorption Properties ◽  
Organic Light ◽  
Sol Gel Process

Abstract A new invisible nanolevel coating has been developed based on the sol-gel process for veneer finishes. The sol synthesis and its application as a protective agent is described. It could be demonstrated that a combination of organic light stabilizers and sol-gel deposits is feasible and that the resulting hybrid inorganic-organic thin films decrease moisture uptake of hardwood veneers.

Alumina Sol-Gel Films and Alodine Films on Al 2024 Alloy

2011 ◽  
Vol 356-360 ◽  
pp. 364-367
Author(s):  
Qi Zhou ◽  
Xuan Xiao ◽  
Da Li Zhao ◽  
En Jun Song
Keyword(s):  
Corrosion Resistance ◽  
Aluminium Alloy ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Film Surface ◽  
Corrosion Current ◽  
Promising Alternative ◽  
Gel Film ◽  
Alumina Sol ◽  
Sol Gel Films

Development of the sol-gel films for painting pretreatment of aluminium alloy is to replace bichromate conversion films such as Alodine. Corrosion resistance of Alodine film and sol-gel film were evaluated through potentiodynamic polarization curves, electrochemical impedance spectroscopy, salt spraying and acidic dropping solution. Sol-gel film is almost the same as Alodine film at the film surface density, salt spraying resistance and adhesion with painting coating. Changing color times of dropping solution on sol-gel film is shorter than Alodine film. But the corrosion current of sol-gel film is lower than Alodine and the impedance value is higher than Alodine in 35g/L NaCl solution. Mechanism of corrosion resistance of alumina sol-gel film is that the cathode reaction and anodic reactions are restrained by sol-gel film in the Cl- corrosive medium. The EIS of sol-gel film consisted of only a single capacitive arc with one time constant. Sol-gel coating can prevent or delay the corrosive solution from infiltrating the substrate for its better isolation function, thus protecting 2024 aluminium alloy from corrosion. Sol-gel films can improve corrosion resistance of aluminum alloy and have the same adhesion as Alodine film. It will be a promising alternative pretreatment for aluminum alloys prior to painting.

Fabrication of heteropolyoxometalate-based photochromic inorganic–organic nanocomposites

2001 ◽  
Vol 16 (8) ◽  
pp. 2256-2263 ◽  
Author(s):  
Tie Rui Zhang ◽  
Wei Feng ◽  
Chun Yan Bao ◽  
Ran Lu ◽  
Xin Tong Zhang ◽  
...  
Keyword(s):  
Sol Gel ◽  
Organic Matrix ◽  
Transfer Model ◽  
X Ray Diffraction ◽  
Transparent Films ◽  
Spin Resonance ◽  
Gel Film ◽  
A Charge ◽  
Sol Gel Films ◽  
Charge Transfer Model

A series of photochromic sol-gel films are prepared through entrapping tungsten heteropolyoxometallates (PW12O403−, SiW12O404−) and molybdenum heteropolyoxometallate (PMo12O403−) into a kind of inorganic–organic matrix cohydrolyzed from tetraethylorthosilicate and 3-aminopropyltriethoxysilane. The films show reversible photochromicity. Irradiated with ultraviolet light, the transparent films change from colorless to blue. Then, bleaching occurs when the films are in contact with air or O2 in the dark. The Keggin-type polyanions interact with R–NH3+ cations strongly, and thus disperse uniformly in the sol-gel matrix, as proved by Fourier transform infrared spectra and x-ray diffraction. The molybdenum heteropolyoxometallate sol-gel film has higher photochromic efficiency and much slower bleaching than its counterparts of tungsten heteropolyoxometallate. A charge-transfer model which is supported by electron spin resonance and related literature [T. Yamase, Chem. Rev. 98, 307, (1998)] is put forth to explain the above experimental results.

Effect of Different Dip-Coating Techniques on TiO2 Thin Film Properties

2016 ◽  
Vol 721 ◽  
pp. 128-132 ◽  
Author(s):  
Kaspars Malnieks ◽  
Gundars Mezinskis ◽  
Ilona Pavlovska
Keyword(s):  
Thin Film ◽  
Photocatalytic Activity ◽  
Sol Gel ◽  
Soda Lime ◽  
Nanorod Array ◽  
Dip Coating ◽  
Film Structure ◽  
Glass Slides ◽  
Soda Lime Silicate Glass ◽  
Sol Gel Films

TiO2 three-layer sol-gel films have been deposited on soda-lime silicate glass slides and dried in two different ways to study the effect of drying on thin film structure. The structural properties, surface topography and photocatalytic activity of the films were studied by X-ray diffraction, atomic force microscopy, and by analysing photocatalytic degradation of methyl orange, respectively. The titanium oxide sol-gel layers on glass slides dried at 20 °C before the deposition of next layers after final calcination at 500 °C resulted in a nanorod array film with good photocatalytic activity.

Microhardness Characterization of 80/20 MOL % TiO2/SiO2 Sol-Gel Films

1991 ◽  
Vol 239 ◽  
Author(s):  
S. M. Melpolder ◽  
A. W. West ◽  
C. L. Bauer
Keyword(s):  
Thin Film ◽  
Indentation Depth ◽  
Sol Gel ◽  
Knoop Hardness ◽  
Film Properties ◽  
Knoop Microhardness ◽  
Sol Gel Films ◽  
Microscopy Techniques ◽  
Substrate Influence

ABSTRACTKnoop hardness and nanoindentation studies were performed on single and multilayered 80/20 mol % TiO2/SiO2 films spin-coated onto [100] silicon wafers. The Knoop microhardness results indicated that a total sol-gel thickness (h) to indentation depth (h*) ratio of >2 was sufficient to obtain reliable thin film properties independent of substrate influence. Electron microscopy techniques were used to determine the sample's absolute film thickness, to examine the morphology of the indentations, and to determine the phase of the sol-gel thin films.

Modification of Electroless Nickel-Plating Coatings with Sol-Gel Film

2005 ◽  
Vol 475-479 ◽  
pp. 3835-3838 ◽  
Author(s):  
Hui Cong Liu ◽  
Liqun Zhu ◽  
Yan Bin Du
Keyword(s):  
Heat Treatment ◽  
Oxidation Resistance ◽  
Sol Gel ◽  
Electroless Nickel ◽  
Dip Coating ◽  
Treatment Temperature ◽  
Gel Film ◽  
Sol Gel Films ◽  
Corrosion And Oxidation

Four Sol-Gel films were developed by dip-coating electroless nickel-plated samples in different Sols, followed by heat treatment. The effects of the coating times and heat treatment temperature on the corrosion, oxidation resistance and wearing quality of the modified coating were examined. Results show that, after six coating, Sol-Gel films obtained can provide good corrosion and oxidation resistance, and their anti-corrosion quality remains high even after being oxidized at 500 °C for 60 hours. Addition of inorganic molybdenum salt or chromate into the Ti Sol also makes the wearing quality of the Sol-Gel film better.

A third-generation hydrogen peroxide biosensor based on horseradish peroxidase immobilized by sol–gel thin film on a multi-wall carbon nanotube modified electrode

2014 ◽  
Vol 6 (16) ◽  
pp. 6310-6315 ◽  
Author(s):  
Shu-Xia Xu ◽  
Jia-Ling Li ◽  
Zhi-Ling Zhou ◽  
Cheng-Xiao Zhang
Keyword(s):  
Thin Film ◽  
Horseradish Peroxidase ◽  
Sol Gel ◽  
Carbon Electrode ◽  
Third Generation ◽  
Glass Carbon Electrode ◽  
Gel Film ◽  
Glass Carbon ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

A third-generation H2O2 biosensor was developed by using tetraethoxy-silicone sol–gel film to immobilize horseradish peroxidase (HRP) on a multi-walled carbon nanotubes (MWNTs) modified glass carbon electrode.

Chemical Control of Stress in Sol-Gel Derived Titania Films and Their Pressure Dependent Optical Properties

1988 ◽  
Vol 121 ◽  
Author(s):  
Wendy S. Frydrych ◽  
Gregory J. Exarhos ◽  
Kim F. Ferris ◽  
Nancy J. Hess
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Bulk Material ◽  
Sol Gel ◽  
Applied Pressure ◽  
Transmission Electron ◽  
Gel Film ◽  
Diamond Anvil ◽  
Sputter Deposited ◽  
Sol Gel Films

ABSTRACTOptical properties and durability of thin films are influenced by strain which can be evaluated from frequency shifts of the lattice phonon lines in measured Raman spectra. The response of titania samples to applied pressure is reported in this work. Anatase and rutile samples of thin films (sol-gel and sputter deposited) and bulk materials have been subjected to hydrostatic pressures approaching 100 kbar in a diamond anvil cell. Results indicate that the rutile samples exhibit similar responses to applied pressure. Anatase sol-gel films exhibit a pressure-dependent response that suggests that the sol-gel film is more compressible than the bulk material, and a pressure-induced phase transformation observed for the bulk material is inhibited in the anatase sol-gel film. The anomalous pressure response of the anatase sol-gel film may result from the film microstructure which has been shown by transmission electron microscopy to consist of spheres of crystalline TiO2 surrounded by microscopic voids.

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