Accelerated weathering of wood surfaces coated with multifunctional alkoxysilanes by sol-gel deposition

2003 ◽  
Vol 75 (8) ◽  
pp. 37-43 ◽  
Author(s):  
Mandla A. Tshabalala ◽  
John E. Gangstad
Keyword(s):  
Sol Gel ◽  
Accelerated Weathering ◽  
Wood Surfaces

scholarly journals Plasma Pre-treatments to Improve the Weather Resistance of Polyurethane Coatings on Black Spruce Wood

Coatings ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 8 ◽  
Author(s):  
Jonathan Haase ◽  
Lukie Leung ◽  
Philip Evans
Keyword(s):  
Plasma Treatment ◽  
Black Spruce ◽  
Accelerated Weathering ◽  
Polyurethane Coatings ◽  
Plasma Treatments ◽  
Spruce Wood ◽  
Coating Type ◽  
Weather Resistance ◽  
Wood Surfaces ◽  
Modified Wood

We hypothesize that plasma treatments that increase the adhesion and penetration of transparent water, and solvent-borne polyurethane coatings into black spruce wood will improve the performance of coated wood exposed to accelerated weathering. We tested this hypothesis by modifying wood samples with plasma for 30, 180, 600, and 1200 s, and measuring coating penetration and adhesion using light microscopy and a mechanical pull-off test, respectively. Plasma treatment did not improve coating adhesion, but the solvent-borne coating showed deeper penetration into plasma-modified wood, and its resistance to accelerated weathering was better on plasma-modified wood than on untreated controls. Plasma treatments enhanced the penetration of water-borne polyurethane into wood, but the treatments did not improve weather-resistance of the coating. Plasma treatment increased the wettability of wood surfaces, and prolonged plasma treatment etched cell walls, increasing their porosity. These effects may explain the positive effect of plasma treatment on coating penetration, and the increased weather-resistance of the solvent-borne polyurethane on plasma-modified wood. In conclusion, our results indicate that the ability of plasma treatment to improve coating performance on black spruce depends on the coating type, and the effects of the treatment on the surface microstructure of wood.

scholarly journals Efficacy of Hydrophobic Coatings in Protecting Oak Wood Surfaces during Accelerated Weathering

Coatings ◽  
2017 ◽  
Vol 7 (10) ◽  
pp. 172 ◽  
Author(s):  
Miloš Pánek ◽  
Eliška Oberhofnerová ◽  
Aleš Zeidler ◽  
Přemysl Šedivka
Keyword(s):  
Accelerated Weathering ◽  
Hydrophobic Coatings ◽  
Oak Wood ◽  
Wood Surfaces

Accelerated Weathering of Wood Surfaces Modified by Chromium Trioxide

Holzforschung ◽  
1998 ◽  
Vol 52 (5) ◽  
pp. 467-471 ◽  
Author(s):  
Krishna K. Pandey ◽  
Dwarika P. Khali
Keyword(s):  
Chromium Trioxide ◽  
Accelerated Weathering ◽  
Wood Surfaces

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.

scholarly journals Optimization of the effect of accelerated weathering conditions on wood surfaces via the Taguchi method

BioResources ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 1642-1653
Author(s):  
Rifat Kurt ◽  
Ahmet Can
Keyword(s):  
Taguchi Method ◽  
Scots Pine ◽  
Color Change ◽  
Accelerated Weathering ◽  
Color Changes ◽  
Uv Irradiance ◽  
Total Color Change ◽  
Uv Lamps ◽  
Wood Surfaces ◽  
Cutting Direction

This study investigated the effect of accelerated weathering conditions on total color changes on Scots pine (Pinus sylvestris L.) and poplar (Populus x euroamericana) wood surfaces using the Taguchi method. The experiments, based on the L18 orthogonal array, were conducted separately for both tree species. The radial and tangential surfaces of wood specimens were subjected to an accelerated weathering process using 340 nm ultraviolet (UV) lamps and temperature conditions of 50 °C. The factors for the minimum color change were determined via the signal-to-noise (S/N) ratios of the four parameters thought to be effective on color change. These parameters were cutting direction (two levels), UV-irradiance, conditioning, and water (three levels each). The most important factor affecting the color change was then determined by analysis of variance (ANOVA) testing. The results showed that the maximum UV-irradiance (W/m2) had the largest effect on the total color change, while the cutting direction (radial and tangential) had the smallest effect. The factors that affected the total color change of the poplar and Scots pine wood specimens were the same. However, the analysis revealed that different application times had varying effects on the color change.

Effect of Additives on the Durability and Properties of Antireflective Films for Solar Glass Covers

2007 ◽  
Vol 130 (1) ◽  
Author(s):  
Gema San Vicente ◽  
Rocío Bayón ◽  
Angel Morales
Keyword(s):  
Sol Gel ◽  
Single Layer ◽  
Precursor Solution ◽  
Accelerated Weathering ◽  
Silica Films ◽  
A Value ◽  
Effect Of Additives ◽  
Antireflective Films ◽  
Low Refractive Index

Generally, single layer antireflective (AR) coatings are based on SiO2 for which the low refractive index is achieved by increasing the porosity of the films. On the other hand, the increase of porosity on any material results in a decrease of its mechanical properties. In addition to increasing the solar transmittance, it is equally important that the AR film is long-term stable for its application in solar collectors. In this sense, the objective of our work has been to develop a film that exhibits good AR properties and physical durability as well. In the present study, sol-gel silica films have been deposited on borosilicate glass. The effect of adding some organic compounds to the precursor solution in the properties of the films has been studied. Moreover, accelerated weathering tests have been performed in order to investigate the outdoor durability. A value of solar transmittance as high as 0.974 has been obtained by using a porosity promoter additive. However, the durability tests have shown the necessity of incorporating a hydrophobic additive to the precursor solutions in order to avoid the degradation of the optical properties of the films. 1.5% decrease in solar transmittance is observed after 1900h in the weathering chamber for films prepared with methyltriethoxysilane.

TEM visualization of surface replicated acid and base catalyzed sol-gel glasses

1986 ◽  
Vol 44 ◽  
pp. 448-449
Author(s):  
George C. Ruben ◽  
Merrill W. Shafer
Keyword(s):  
Elevated Temperatures ◽  
Sol Gel ◽  
Basic Medium ◽  
Glass Transition Point ◽  
Structural Space ◽  
Acid And Base ◽  
Organometallic Precursors ◽  
New Processing ◽  
Gel Glasses ◽  
Physical Phenomena

Traditionally ceramics have been shaped from powders and densified at temperatures close to their liquid point. New processing methods using various types of sols, gels, and organometallic precursors at low temperature which enable densificatlon at elevated temperatures well below their liquidus, hold the promise of producing ceramics and glasses of controlled and reproducible properties that are highly reliable for electronic, structural, space or medical applications. Ultrastructure processing of silicon alkoxides in acid medium and mixtures of Ludox HS-40 (120Å spheres from DuPont) and Kasil (38% K2O &62% SiO2) in basic medium have been aimed at producing materials with a range of well defined pore sizes (∼20-400Å) to study physical phenomena and materials behavior in well characterized confined geometries. We have studied Pt/C surface replicas of some of these porous sol-gels prepared at temperatures below their glass transition point.

Electron microscopy studies of PZT ferroelectric film capacitor structures

1992 ◽  
Vol 50 (2) ◽  
pp. 1364-1365
Author(s):  
V. Kaushik ◽  
P. Maniar ◽  
J. Olowolafe ◽  
R. Jones ◽  
A. Campbell ◽  
...  
Keyword(s):  
Electric Fields ◽  
Sol Gel ◽  
Ferroelectric Material ◽  
Dielectric Constants ◽  
Dielectric Films ◽  
Lead Zirconium Titanate ◽  
Si Substrate ◽  
Film Capacitor ◽  
Pzt Films ◽  
High Dielectric

Lead zirconium titanate films (Pb (Zr,Ti) O3 or PZT) are being considered for potential application as dielectric films in memory technology due to their high dielectric constants. PZT is a ferroelectric material which shows spontaneous polarizability, reversible under applied electric fields. We report herein some results of TEM studies on thin film capacitor structures containing PZT films with platinum-titanium electrodes.The wafers had a stacked structure consisting of PZT/Pt/Ti/SiO2/Si substrate as shown in Figure 1. Platinum acts as electrode material and titanium is used to overcome the problem of platinum adhesion to the oxide layer. The PZT (0/20/80) films were deposited using a sol-gel method and the structure was annealed at 650°C and 800°C for 30 min in an oxygen ambient. XTEM imaging was done at 200KV with the electron beam parallel to <110> zone axis of silicon.Figure 2 shows the PZT and Pt layers only, since the structure had a tendency to peel off at the Ti-Pt interface during TEM sample preparation.

Sign in / Sign up

Export Citation Format

Share Document