Sol-Gel Films With Tailored Microstructures

1992 ◽  
Vol 271 ◽  
Author(s):  
Deborah L. Logan ◽  
Carol S. Ashley ◽  
C. Jeffrey Brinker
Keyword(s):  
Sol Gel ◽  
Dip Coating ◽  
Film Deposition ◽  
Organic Species ◽  
Fractal Clusters ◽  
Acid And Base ◽  
Before And After ◽  
Sol Gel Films ◽  
Film Porosity ◽  
Dip Coated Films

ABSTRACTThe refractive index and porosity of silicate films formed by dip-coating were tailored by varying the aging time of a two-step acid- and base-catalyzed sol to control the size and structure of the polymeric species prior to coating. 29Si NMR showed that there was a 2% increase in the total number of bridging oxygens with sol age, consistent with a cluster-cluster growth mechanism. However, several percent monomer remained regardless of aging. Dip-coated films were characterized by ellipsometry before and after heating to moderate temperatures at three rates. Sol aging prior to film deposition leads to greater film porosity, consistent with the concept of aggregation of fractal clusters, but only after a heat treatment to remove the organic species associated with incompletely hydrolyzed monomers from the pores.

Ellipsometric Imaging of Drying Sol-Gel Films

1988 ◽  
Vol 121 ◽  
Author(s):  
Alan J. Hurd ◽  
C. Jeffrey Brinker
Keyword(s):  
Refractive Index ◽  
Sol Gel ◽  
Dip Coating ◽  
Drying Process ◽  
Imaging Ellipsometry ◽  
Withdrawal Velocity ◽  
Coated Film ◽  
Sol Gel Films ◽  
Physical And Chemical ◽  
Dip Coated Films

ABSTRACTAlthough controlled dip-coating is an established way to apply high quality uniform coatings, the details of the coating and drying process have not been deeply studied. Depending on the physical and chemical state of the sol and the parameters of dipping (dipping angle and speed), a variety of thicknesses and porosities can be achieved [1]. For optical coatings, the refractive index and optical thickness can thereby be controlled.We have developed a method to view the drying front of a dip-coated film using broad beam ellipsometry [2], or “ellipsometric imaging.” In dip-coated films we take full advantage of the fact that a steady state is quickly reached where the drying line velocity matches the withdrawal velocity; however, the technique might also be used in unsteady situations such as spin coating. Imaging ellipsometry makes it possible to measure the refractive index and thickness profiles of both wet and dry films point-by-point in an entire image at once. These profiles provide important clues as to the relative importance of gravity, evaporation and other phenomena.

Numerical simulation of the liquid phase in SnO2 thin film deposition by sol-gel-dip-coating

2010 ◽  
Vol 55 (3) ◽  
pp. 385-393 ◽  
Author(s):  
Dayene M. Carvalho ◽  
Jorge L. B. Maciel ◽  
Leandro P. Ravaro ◽  
Rogério E. Garcia ◽  
Valdemir G. Ferreira ◽  
...  
Keyword(s):  
Thin Film ◽  
Numerical Simulation ◽  
Liquid Phase ◽  
Sol Gel ◽  
Thin Film Deposition ◽  
Dip Coating ◽  
Film Deposition ◽  
Sno2 Thin Film

Nano-crystal V[sub 2]O[sub 5]nH[sub 2]O sol-gel films made by dip coating

2012 ◽  
Author(s):  
Orhan Özdemir ◽  
F. Pınar Gökdemir ◽  
U. Deneb Menda ◽  
Pelin Kavak ◽  
A. Evrim Saatci ◽  
...  
Keyword(s):  
Sol Gel ◽  
Dip Coating ◽  
Nano Crystal ◽  
Sol Gel Films

Improving of Tribological Properties of Nanocomposites Sol-Gel Thin Films by Fluorocyclophosphazene Derivatives

2005 ◽  
Author(s):  
G. Celichowski ◽  
K. Chrobak
Keyword(s):  
Thin Films ◽  
Tribological Properties ◽  
Sol Gel ◽  
Dip Coating ◽  
Rf Plasma ◽  
Good Thermal Stability ◽  
Force Microscopy ◽  
Coating Method ◽  
Dip Coating Method ◽  
Sol Gel Films

Fluorocyclophospazenes’ derivatives were used as modifiers for improving tribological properties of thin films prepared by sol-gel technique. Thin films were made on the base of aminopropyltriethoxysilane (APTS). All films were deposited by dip-coating method and post-treated by heat, UV radiation and low pressure of RF plasma. Chemical changes in sol-gel films during all steps of post-treatments and modifications were monitored by FT-IR spectroscopy and SIMS spectrometry. Topographies of modified surfaces were imaged by Atomic Force Microscopy (AFM). After final modification significant improvements of frictional properties were observed as well as their very good thermal stability.

Preparation of Sol−Gel Films by Dip-Coating in Extreme Conditions

2010 ◽  
Vol 114 (17) ◽  
pp. 7637-7645 ◽  
Author(s):  
Marco Faustini ◽  
Benjamin Louis ◽  
Pierre A. Albouy ◽  
Monika Kuemmel ◽  
David Grosso
Keyword(s):  
Sol Gel ◽  
Dip Coating ◽  
Extreme Conditions ◽  
Sol Gel Films

Investigation of The Elastic Modulus of Sol-Gel Derived Titania Using Three-Point Bending Tests

1996 ◽  
Vol 436 ◽  
Author(s):  
Å. K. Jämting ◽  
J. M. Bell ◽  
M. V. Swain
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Sol Gel ◽  
Bending Tests ◽  
Three Point Bending ◽  
Compositional Uniformity ◽  
Titania Films ◽  
Sol Gel Films ◽  
Film Porosity ◽  
Thickness Measurements

AbstractThere is increasing interest in the use of sol-gel derived films in tribological applications, and this necessitates an understanding of the mechanical properties of these films. Few investigations into the mechanical properties of sol-gel films have been undertaken, and in this study we have concentrated on measurement of the elastic modulus of sol-gel derived titania films as a preliminary stage in a full investigation of stress in sol-gel deposited thin films. Sol-gel films are often very thin and in order to understand the influence of the substrate on the measured elastic modulus, we have used a multiple coating technique to deposit titania films of increasing thickness on various substrates. A three point bending apparatus is used to measure the elastic modulus. The three-point bending apparatus has very low load and displacement measuring capabilities as is required for the very thin sol-gel films. Measurements of the compositional uniformity of the films have been performed using RBS, and this has been combined with film thickness measurements to determine the film porosity. This information ensures that the measured properties relate to intrinsic film properties. The results of all these measurements will be presented.

scholarly journals Optimization of Ormosil Glasses for Luminescence Based Dissolved Oxygen Sensors

2010 ◽  
Vol 161 ◽  
pp. 1-11 ◽  
Author(s):  
J. Palmeira ◽  
L. Lopes ◽  
A.J. Silva ◽  
P.A.S. Jorge ◽  
A. Oliva
Keyword(s):  
Dissolved Oxygen ◽  
Optical Sensors ◽  
Ruthenium Complex ◽  
Oxygen Sensing ◽  
Sol Gel ◽  
Dip Coating ◽  
Oxygen Sensors ◽  
Quenching Efficiency ◽  
Sol Gel Films ◽  
The Impact

In the recent years, sol-gel films have been intensively used in optical sensors configurations. Due to its hydrophobic nature, ormosil films have been reported to be a promising supporting matrix for oxygen sensing dyes for measurements in aqueous media. In this work, the impact of the sol-gel host fabrication parameters in the characteristics of the resulting oxygen sensing membranes is thoroughly evaluated. Different combinations of organic-inorganic precursors, with different aging times, were tested as oxygen sensors. All the solution were doped with ruthenium complex Ru(II)-tris(4,7-diphenyl-1,10-phenanthroline) to introduce oxygen sensitivity. Thin films were produced by dip coating of glass slides. The oxygen sensitive films were tested in aqueous phase in equilibrium with different oxygen gas compositions, using a phase-modulation technique. Sensor performance parameters such as Stern-Volmer constant, quenching efficiency and lifetime response are reported. The data obtained clearly indicates that increased aging times and longer organic groups produce sensors with the highest sensitivity to dissolved oxygen. From all sol-gel films produced, the BTEOS:TEOS (1:1) mixture is the most promising for sensor construction.

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.

scholarly journals Sol-gel derived coatings for the conservation of steel

2015 ◽  
Vol 9 (2) ◽  
pp. 81-89 ◽  
Author(s):  
Erika Kiele ◽  
Jurate Senvaitiene ◽  
Asta Grigucevicienė ◽  
Rimantas Ramanauskas ◽  
Rimantas Raudonis ◽  
...  
Keyword(s):  
Sol Gel ◽  
Dip Coating ◽  
Processing Route ◽  
Force Microscopy ◽  
Angle Measurements ◽  
Before And After ◽  
Silica Sols ◽  
Commercial Polymers ◽  
Dip Coating Technique ◽  
Steel Substrates

In this paper, sol-gel processing route has been applied and investigated for the conservation of steel. Nanosilica coatings on steel surface have been prepared using tetraethylorthosilicate (TEOS) as a starting material. The methyl-modified silica sols were obtained by mixing of 3mas.% SiO2 sol solution with hexamethyldisilozane (HMDS). The surface of steel was coated by dip-coating technique. In order to compare the characteristics of coatings, the steel substrates were also coated with commercial polymers Paraloid B67, Cosmolloid H80 and Antik Patina. The surface morphology changes of the uncoated and coated specimens before and after photochemical ageing were investigated by scanning electron microscopy and atomic force microscopy. The structure of the prepared coatings was also investigated by FTIR spectroscopy. The hydrophobicity of surfaces was evaluated by contact angle measurements. Potentiodynamic measurements were obtained in order to compare corrosion parameters of the coatings.

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