Silica/Silicone Nanocomposite Films: A New Concept in Corrosion Protection

1992 ◽  
Vol 274 ◽  
Author(s):  
Theresa E. Gentle ◽  
Ronald H. Baney
Keyword(s):  
Thin Films ◽  
Optical Microscopy ◽  
Composite Films ◽  
Dip Coating ◽  
Nanocomposite Films ◽  
Nanoporous Silica ◽  
Silica Films ◽  
Aluminum Panels ◽  
Organic Solutions ◽  
Salt Fog

ABSTRACTThin films of silsesquioxane, (HSiO3/2)n, were applied to aluminum panels and to CMOS microelectronic circuit surfaces by spin or dip coating organic solutions of the silsesquioxane. Nanoporous silica was obtained by oxidation of the silsesquioxane. These nanoporous silica films were then vacuum infiltrated with various viscosities of polydimethylsiloxanes (PDMS) to form hydrophobic nanocomposites. The nanocomposite films were shown to provide superior hermetic protection against salt fog exposure when compared to PDMS and silica films alone.The composite films were characterized by FTIR and optical microscopy. FTIR spectra showed that the silica served as a skeletal framework holding the hydrophobic PDMS in place and preventing loss of adhesion. This is in contrast to PDMS films alone in which blistering of the film from the substrate can occur, thus, allowing ions and moisture to reach the surface and corrosion to take place.

Sol-gel synthesis and characterization of Ag nanoparticles in ZrO2 thin films

2009 ◽  
Vol 24 (8) ◽  
pp. 2541-2546 ◽  
Author(s):  
Eisuke Yokoyama ◽  
Hironobu Sakata ◽  
Moriaki Wakaki
Keyword(s):  
Thin Films ◽  
Sol Gel ◽  
Composite Films ◽  
Dip Coating ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Silver Surface ◽  
Molar Ratios ◽  
Sol Gel Synthesis

ZrO2 thin films containing silver nanoparticles were prepared using the sol-gel method with Ag to Zr molar ratios [Ag]/[Zr] = 0.11, 0.25, 0.43, 0.67, 1.00, 1.50, and 2.33. After dip coating on glass substrate, coated films were annealed at 200 and 300 °C in air. X-ray diffraction peaks corresponding to crystalline Ag were observed, but a specific peak corresponding to ZrO2 was not observed. At the molar ratio [Ag]/[Zr] = 0.25, the particle size of Ag distributed broadly centered at 17 nm for an annealing temperature of 200 °C and at 25 nm for 300 °C. The films annealed in air at 200 °C showed an absorption band centered at 450 nm because of the silver surface plasmon resonance, whereas films heated at 300 °C in air caused a red shift of the absorption to 500 nm. The absorption peak was analyzed using the effective dielectric function of Ag-ZrO2 composite films modeled with the Maxwell-Garnett expression.

Photocatalytic Degradation of Humic Acid Using Fe3+ and N-Doped 3SnO2/TiO2 Thin Films Coated on Glass Fibers

2014 ◽  
Vol 608 ◽  
pp. 164-169
Author(s):  
Peerawas Kongsong ◽  
Lek Sikong ◽  
Sutham Niyomwas ◽  
Vishnu Rachpech
Keyword(s):  
Thin Films ◽  
Photocatalytic Activity ◽  
Humic Acid ◽  
Glass Fibers ◽  
Sol Gel ◽  
Composite Films ◽  
Dip Coating ◽  
High Photocatalytic Activity ◽  
Coating Methods ◽  
Uv Lamp

The Fe3+ and N–doped 3SnO2/TiO2 composite thin films and undoped films coated on glass fibers were prepared by sol–gel and dip–coating methods. The films were calcined at 600°C for 2 hour and characterized by XRD, SEM, EDS and XPS. The photocatalytic activity of the coated glass fibers was determined by means of degradation of a methylene blue (MB) solution and humic acid (HA). It was found that the optimized 20N/3SnO2/TiO2composite films exhibit a high photocatalytic activity and HA could be rapidly removed from water. The main factor affecting the HA degradation of 20N/3SnO2/TiO2 films is quantity of glass fibers loading, irradiation power of UV lamp and flow rate of water.

scholarly journals Graphene Oxide Reinforced Polycarbonate Nanocomposite Films with Antibacterial Properties

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
R. Mahendran ◽  
D. Sridharan ◽  
K. Santhakumar ◽  
T. A. Selvakumar ◽  
P. Rajasekar ◽  
...  
Keyword(s):  
Thin Films ◽  
Graphene Oxide ◽  
Low Cost ◽  
Thermal Studies ◽  
Composite Films ◽  
Antibacterial Properties ◽  
Antibacterial Activities ◽  
Nanocomposite Films ◽  
Matrix Microstructure ◽  
Phase Inversion Technique

The incorporation of carbonaceous nanofillers into polymers can result in significant materials with improved physicochemical properties and novel composite functionalities. In this study, we have fabricated antibacterial, lightweight, transparent, and flexible graphene oxide (GO) reinforced polycarbonate thin films by a facile and low-cost methodology. Solution blending is employed to get a homogeneous mixture of PC-GO composites at various loading of GO, and the thin films are prepared by dry-wet phase inversion technique. Thermal studies and micrographs of the films revealed the incorporation of GO in PC matrix. Microstructure of the thin films showed the homogeneous dispersion of GO at micro- and nanoscales; however, at higher loading of GO (0.7%), significant agglomeration is observed. More importantly, PC-GO composite films exhibited excellent antibacterial activities against E. coli and S. aureus, owing to the antibacterial nature of GO nanoparticles.

scholarly journals Optical, Structural, and Crystal Defects Characterizations of Dip Synthesized (Fe-Ni) Co-Doped ZnO Thin Films

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1737 ◽  
Author(s):  
Ahmad M. Alsaad ◽  
Ahmad A. Ahmad ◽  
Qais M. Al-Bataineh ◽  
Areen A. Bani-Salameh ◽  
Hadeel S. Abdullah ◽  
...  
Keyword(s):  
Thin Films ◽  
Structural Properties ◽  
Sol Gel ◽  
Dip Coating ◽  
Crystal Defects ◽  
Nanocomposite Films ◽  
Zno Thin Films ◽  
Line Profile Analysis ◽  
Doped Zno ◽  
Co Doped

Sol-gel technique is used to synthesize as-grown zinc oxide (ZnO) and iron-nickel (Fe-Ni) co-doped ZnO thin films deposited on glass substrates using dip coating technique. The structural properties and crystal imperfections of as-prepared thin films are investigated. We performed the structural analysis of films using X-ray diffraction (XRD). The XRD analysis reveal that the as-prepared films exhibit wurtzite structure. Furthermore, XRD-line profile analysis is performed to study the correlation between structural properties and imperfections of the nanocomposite thin films. The crystallite size and microstrains parameters are predicted using the Williamson–Hall method. We found that the crystallites size increases as the co-doped (Fe-Ni) concentration is increased. However, microstrains of the nanocomposite films decreases as (Fe-Ni) concentration is increased. The optical properties of the (Fe-Ni) co-doped nanocomposite films are investigated by performing UV-Vis (250 nm–700 nm) spectrophotometer measurements. We found that as the (Fe-Ni) concentration level is steadily increased, transmittance of the undoped ZnO thin films is decreased. Remarkably, refractive index of undoped ZnO thin films is found to exhibit values extending from 1.55 to1.88 that would increase as (Fe-Ni) concentration is increased.

Nano Composite PVA-TiO2 Thin Films for OTFTs

2013 ◽  
Vol 678 ◽  
pp. 335-342 ◽  
Author(s):  
S. Sathish ◽  
Bellan Chandar Shekar ◽  
B.T. Bhavyasree
Keyword(s):  
Thin Films ◽  
Surface Morphology ◽  
Composite Films ◽  
Gravimetric Method ◽  
Dip Coating ◽  
Polymer Matrices ◽  
Poly Vinyl Alcohol ◽  
Organic Thin Film ◽  
Composite Polymer ◽  
Amorphous Nature

Pure PVA and composite thin films of poly vinyl alcohol (PVA)/Titanium dioxide (TiO2) were prepared on pre-cleaned glass substrates by Dip Coating Technique (DCT) and Metal Organic Deposition Technique (MODT). EDS and FTIR spectrum were used to identify the composition of the prepared films. The vibrational peaks observed at 1260 cm-1 and 851 cm-1 are assigned to C–C stretching and CH rocking of PVA. The characteristic band appearing at 1432 cm-1 is assigned to C–H bend of CH2 of PVA. The bands observed around 847 cm-1 and 601cm-1 belong to the asymmetric stretching of Ti–O–Ti groups. The last band at 460 cm-1 is due to the bending mode of Ti–O–Ti. The bands covered by Ti-O were located at 540, 700 and 950 cm-1. From the FTIR spectra, it is observed that some of the peaks of composite films were shifted and some of them were disappeared with respect to the pure compounds. This results manifested the conclusion about the specific interactions in composite polymer matrices and hence the complexation. Thus, complex formation in the composite polymer matrices has been confirmed from this analysis. The thickness of the coated films were measured by using an electronic thickness measuring instrument (Tesatronic-TTD-20), gravimetric method and cross checked by optical spectrophotometer. XRD spectra indicated the amorphous nature of the films. Surface morphology of the coated films was studied by scanning electron microscope (SEM). The surface revealed no pits and pin holes on the surface. Both as grown and annealed films showed predominantly amorphous nature. The observed surface morphology and thermal stability indicated that these films could be used as dielectric layer in organic thin film transistors.

Synthesis and Characterization of BaTiO3/CoFe2O4 thin films

2011 ◽  
Vol 1368 ◽  
Author(s):  
Helen R. C. S. Andrade ◽  
Luciana M. Seara ◽  
Nelcy D. S. Mohallem
Keyword(s):  
Thin Films ◽  
Barium Titanate ◽  
Cobalt Ferrite ◽  
Sol Gel ◽  
Dip Coating ◽  
Ferroelectric Materials ◽  
Nanocomposite Films ◽  
Ferrite Film ◽  
Vis Spectroscopy ◽  
Quartz Substrates

ABSTRACTNanocomposites formed by ferrimagnetic and ferroelectric materials are multiferroic material in which magnetoelectric coupling occurs via piezoelectricity and magnetostriction phenomena. These nanocomposites have a variety of applications in tunable microwave devices using electric control of spin wave propagation or new magnetic memories in which the magnetic response is controlled by electric field.In this work, transparent and homogeneous thin films of barium titanate interleaved with cobalt ferrite were prepared by sol–gel method using dip-coating process. Films of pure barium titanate and cobalt ferrite were also prepared for comparison. The nanocomposite films were deposited onto clean quartz substrates, where a coating of each material was deposited interleaved, where the cobalt ferrite film formed the last layer. The films were dried in air after each dipping and heated at 900 oC for 1 hour to convert the amorphous films into crystalline ones. The samples were characterized by low angle X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) and UV-Vis spectroscopy.

RETRACTED: Correlation of the Transition Metal Compound Ternary Nitride Thin Films

2014 ◽  
Vol 875-877 ◽  
pp. 605-608
Author(s):  
Yong Jun Jiang
Keyword(s):  
Thin Films ◽  
Transition Metal ◽  
Protective Coatings ◽  
Chemical Reactivity ◽  
Composite Films ◽  
Ternary Systems ◽  
Nanocomposite Films ◽  
Early Transition Metal ◽  
N2 Atmosphere ◽  
Nanocrystalline Composite

Thin films of MXN (M stands for early transition metal and X = Si, Ge, Sn) are studied as protective coatings. To extend the knowledge about the formation of nanocomposite films, various MXN systems have been compared. TiSiN, TiGeN, TiSnN, NbSiN, ZrSiN and CrSiN thin films were deposited by reactive magnetron sputtering, from confocal targets in a mixed Ar/N2 atmosphere. The chemical reactivity of germanium and tin with nitrogen is significantly lower than that of Si and Ti. Therefore, the TiGeN and TiSnN systems are different from TiSiN. Important changes in the morphology and structure of MXNfilms are induced by X addition. Nanocrystalline composite films are formed in all these investigated ternary systems.

Standardization and control of a dip-coating procedure for optical thin films prepared from solution

1988 ◽  
Vol 66 (10) ◽  
pp. 861-867 ◽  
Author(s):  
Daniel W. Hewak ◽  
John W. Y. Lit.
Keyword(s):  
Thin Films ◽  
Refractive Index ◽  
Optical Waveguides ◽  
Volume Fraction ◽  
Composite Films ◽  
Solution Concentration ◽  
Dip Coating ◽  
Optical Quality ◽  
Withdrawal Rate ◽  
And Control

The properties of dip-coated thin films prepared from colloidal silica and titania solutions have been examined. The effects of withdrawal rate, heat treatment, and solution concentration on film thickness, refractive index, and other properties have been studied. Results show that extremely uniform and reproducible thin films with refractive indices between 1.46 and 2.08 and thicknesses up to 0.25 μm can be produced with a single dip. The refractive index of the SiO2:TiO2 composite films varies linearly with the volume fraction of TiO2, and the thickness varies linearly with withdrawal rate. The effects of drying on the final thin film properties are minimal; however, baking conditions have a significant effect, with films shrinking up to 50% and the refractive index increasing 40% during baking. The resulting films are hard, durable, and of good optical quality. We have studied these films for use as planar optical waveguides; however, the results are also applicable to films made for various uses such as optical coatings, filters, or protective layers.

Meso-Ordered Silica Films Formed by Sugar-Based Surfactants

2002 ◽  
Vol 726 ◽  
Author(s):  
Uraka Lavrenèiè-Štangar ◽  
Michael Puchberger ◽  
Nicola Hüsing
Keyword(s):  
Self Assembly ◽  
Hexagonal Phase ◽  
Sol Gel ◽  
Composite Films ◽  
Dip Coating ◽  
Silica Films ◽  
Alkyl Glycosides ◽  
Packing Parameter ◽  
Evaporation Induced Self Assembly ◽  
Nmr Techniques

AbstractSugar-based amphiphilic molecules are used as templates in the sol-gel processing of thin silica films. The films are prepared relying on solvent evaporation-induced self-assembly during dip-coating in a humidity controlled chamber. Different surfactants, such as the commercially available alkyl glycosides (e.g. n-octyl β-D-glucopyranoside and n-dodecyl β-D-maltopyranoside), are compared with respect to their ability to cooperatively self-assemble in alcoholic silicate solutions. The larger polar headgroup (maltose) decreases the critical packing parameter and thus beneficially influences the formation of a favorable hexagonal phase over the lamellar phase, which is formed with the glucose-based surfactant. The inorganic-organic composite films show a strong influence on the humidity during their synthesis. For nonstructured films, ordering could be achieved by exposing the as-deposited films to a high humidity for several hours. The final material is characterized by X-ray diffraction, nitrogen sorption and solid state NMR techniques.

PREPARATION AND CHARACTERIZATION OF POLYVINYL ALCOHOL THIN FILMS FOR ORGANIC THIN FILM TRANSISTORS AND BIOMEDICAL APPLICATIONS

2018 ◽  
Vol 5 (2) ◽  
pp. 16-18
Author(s):  
Chandar Shekar B ◽  
Ranjit Kumar R ◽  
Dinesh K.P.B ◽  
Sulana Sundar C ◽  
Sunnitha S ◽  
...  
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Thin Film Transistors ◽  
Gravimetric Method ◽  
Dip Coating ◽  
Organic Thin Film Transistors ◽  
Poly Vinyl Alcohol ◽  
Organic Thin Film ◽  
Glass Substrates ◽  
Coating Method

Thin films of poly vinyl alcohol (PVA) were prepared on pre-cleaned glass substrates by Dip Coating Method. FTIR spectrum was used to identify the functional groups present in the prepared films. The vibrational peaks observed at 1260 cm-1 and 851 cm-1 are assigned to C–C stretching and CH rocking of PVA.The characteristic band appearing at 1432 cm-1 is assigned to C–H bend of CH2 of PVA. The thickness of the prepared thin films were measured by using an electronic thickness measuring instrument (Tesatronic-TTD20) and cross checked by gravimetric method. XRD spectra indicated the amorphous nature of the films.Surface morphology of the coated films was studied by scanning electron microscope (SEM). The surface revealed no pits and pin holes on the surface. The observed surface morphology indicated that these films could be used as dielectric layer in organic thin film transistors and as drug delivery system for wound healing.

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