Organic/Inorganic Hybrid Sol-Gel Derived Hard Coatings on Plastics

1999 ◽  
Vol 576 ◽  
Author(s):  
C. M. Chan ◽  
G. Z. Cao ◽  
H. Fong ◽  
M. Sarikaya ◽  
T. Robinson ◽  
...  
Keyword(s):  
Low Temperature ◽  
Transition Metal Oxides ◽  
Sol Gel ◽  
Surface Hardness ◽  
Hard Coatings ◽  
Silica Network ◽  
Plastic Surface ◽  
Order Of Magnitude ◽  
Oxygen Plasma Etching ◽  
Optical And Mechanical Properties

ABSTRACTWe investigated sol-gel derived silica based hard coatings on modified polyester substrates. The silica network was modified by incorporating an organic component and adding transition metal oxides. These modifications resulted in tailored thermal, optical and mechanical properties of the coatings. Various low temperature densification techniques were studied including appropriate sol-preparation procedure, enhanced solvent evaporation, ultraviolet (UV) irradiation, and low-temperature (below 150°C) heating. Oxygen plasma etching was applied to improve the adhesion of the sol-gel coatings on the plastic surface. Nanoindentation analysis revealed that the sol-gel coatings have a surface hardness up to 2.5±0.27 GPa, approximately an order of magnitude higher than that of the plastic surface.

Nanoindentation and adhesion of sol-gel-derived hard coatings on polyester

2000 ◽  
Vol 15 (1) ◽  
pp. 148-154 ◽  
Author(s):  
C. M. Chan ◽  
G. Z. Cao ◽  
H. Fong ◽  
M. Sarikaya ◽  
T. Robinson ◽  
...  
Keyword(s):  
Low Temperature ◽  
Transition Metal Oxides ◽  
Sol Gel ◽  
Surface Hardness ◽  
Hard Coatings ◽  
Silica Network ◽  
Plastic Surface ◽  
Order Of Magnitude ◽  
Oxygen Plasma Etching ◽  
Optical And Mechanical Properties

We investigated sol-gel-derived silica-based hard coatings on modified polyester substrates. The silica network was modified by incorporating an organic component and adding transition metal oxides. These modifications resulted in tailored thermal, optical, and mechanical properties of the coatings. Various low-temperature densification techniques were studied including sol-preparation procedure, enhanced solvent evaporation, ultraviolet irradiation, and low-temperature heating (below 150 °C). Oxygen plasma etching was applied to improve the adhesion of the sol-gel coatings on the plastic surface. Nanoindentation analysis revealed that the coatings have a surface hardness up to 2.5 ± 0.27 GPa and an elastic modulus up to 13.6 ± 0.4 GPa, approximately an order of magnitude higher than that of the plastic surface.

Room Temperature Processed Hard Easy Clean Coating Using Ammonia Treatment

2010 ◽  
Vol 447-448 ◽  
pp. 740-744 ◽  
Author(s):  
Xiao Zhang ◽  
Min Qian ◽  
Yu Chan Liu ◽  
Hong Xie
Keyword(s):  
Room Temperature ◽  
Water Drop ◽  
Sol Gel ◽  
High Hardness ◽  
Hard Coatings ◽  
Sliding Angle ◽  
Water Contact ◽  
Pencil Hardness ◽  
Glass Substrates ◽  
Plastic Surface

In this paper we report the fabrication of hydrophobic hard coatings using sol-gel processing and cured at room temperature by an ammonia-assisted process. The coating thickness can be tuned from several hundreds of nanometer to several microns. These coatings show both high transparency (better than PMMA or glass substrates) and high hardness (pencil hardness 2H-4H on PMMA). The coatings are very smooth with surface roughness Ra less than 2 nm for coatings with different thicknesses from 200 nm to 2 m. The water contact angle (WCA) of the coating is about 115 to 120o and the sliding angle for a 20 l water drop is less than 10o. The advantage of this process is the ease for larger area application and especially suitable for plastic surface treatment due to the low temperature curing process.

Microstructural characterization of sol-gel coating on PET films

1994 ◽  
Vol 52 ◽  
pp. 886-887
Author(s):  
R. T. Chen ◽  
R.A. Norwood
Keyword(s):  
Ion Beam ◽  
Sol Gel ◽  
Industrial Applications ◽  
Hard Coatings ◽  
Nanometer Scale ◽  
Ion Beam Sputtering ◽  
Process Technology ◽  
Refractive Index Measurement ◽  
Organically Modified ◽  
Pet Films

Sol-gel processing has been used to control the structure of a material on a nanometer scale in preparing advanced ceramics and glasses. Film coating using the sol-gel process was also found to be a viable process technology in applications such as optical, porous, antireflection and hard coatings. In this study, organically modified silicate (Ormosil) coatings are applied to PET films for various industrial applications. Sol-gel materials are known to exhibit nanometer scale structures which havepreviously been characterized by small-angle X-ray scattering (SAXS), neutron scattering and light scattering. Imaging of the ultrafine sol-gel structures has also been performed using an ultrahigh resolution replica/TEM technique. The objective of this study was to evaluate the ultrafine structures inthe sol gel coatings using a direct imaging technique: atomic force microscopy (AFM). In addition, correlation of microstructures with processing parameters, coating density and other physical properties will be discussed.The materials evaluated are organically modified silicate coatings on PET film substrates. Refractive index measurement by the prism coupling method was used to assess density of the sol-gel coating.AFM imaging was performed on a Nanoscope III AFM (by Digital Instruments) using constant force mode. Solgel coating samples coated with a thin layer of Ft (by ion beam sputtering) were also examined by STM in order to confirm the structures observed in the contact type AFM. In addition, to compare the previous results, sol-gel powder samples were also prepared by ultrasonication followed by Pt/Au shadowing and examined using a JEOL 100CX TEM.

Development of High Permeability Core Materials for Embeddable Inductors in Flexible Organic Substrates

2003 ◽  
Vol 769 ◽  
Author(s):  
C. K. Liu ◽  
P. L. Cheng ◽  
S. Y. Y. Leung ◽  
T. W. Law ◽  
D. C. C. Lam
Keyword(s):  
Low Temperature ◽  
Sol Gel ◽  
Circuit Board ◽  
Organic Substrates ◽  
Circuit Boards ◽  
High Permeability ◽  
Electrical Measurements ◽  
Different Temperatures ◽  
Spiral Inductors ◽  
Ceramic Tape

AbstractCapacitors, resistors and inductors are surface mounted components on circuit boards, which occupy up to 70% of the circuit board area. For selected applications, these passives are packaged inside green ceramic tape substrates and sintered at temperatures over 700°C in a co-fired process. These high temperature processes are incompatible with organic substrates, and low temperature processes are needed if passives are to be embedded into organic substrates. A new high permeability dual-phase Nickel Zinc Ferrite (DP NZF) core fabricated using a low temperature sol-gel route was developed for use in embedded inductors in organic substrates. Crystalline NZF powder was added to the sol-gel precursor of NZF. The solution was deposited onto the substrates as thin films and heat-treated at different temperatures. The changes in the microstructures were characterized using XRD and SEM. Results showed that addition of NZF powder induced low temperature transformation of the sol-gel NZF phase to high permeability phase at 250°C, which is approximately 350°C lower than transformation temperature for pure NZF sol gel films. Electrical measurements of DP NZF cored two-layered spiral inductors indicated that the inductance increased by three times compared to inductors without the DP NZF cores. From microstructural observations, the increase is correlated with the changes in microstructural connectivity of the powder phase.

scholarly journals Elucidation of the Crystal Growth Characteristics of SnO2 Nanoaggregates Formed by Sequential Low-Temperature Sol-Gel Reaction and Freeze Drying

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1738
Author(s):  
Saeid Vafaei ◽  
Alexander Wolosz ◽  
Catlin Ethridge ◽  
Udo Schnupf ◽  
Nagisa Hattori ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Low Temperature ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Freeze Drying ◽  
Sno2 Nanoparticles ◽  
Sol Gel ◽  
Functional Materials ◽  
Cost Effective ◽  
High Concentration

SnO2 nanoparticles are regarded as attractive, functional materials because of their versatile applications. SnO2 nanoaggregates with single-nanometer-scale lumpy surfaces provide opportunities to enhance hetero-material interfacial areas, leading to the performance improvement of materials and devices. For the first time, we demonstrate that SnO2 nanoaggregates with oxygen vacancies can be produced by a simple, low-temperature sol-gel approach combined with freeze-drying. We characterize the initiation of the low-temperature crystal growth of the obtained SnO2 nanoaggregates using high-resolution transmission electron microscopy (HRTEM). The results indicate that Sn (II) hydroxide precursors are converted into submicrometer-scale nanoaggregates consisting of uniform SnO2 spherical nanocrystals (2~5 nm in size). As the sol-gel reaction time increases, further crystallization is observed through the neighboring particles in a confined part of the aggregates, while the specific surface areas of the SnO2 samples increase concomitantly. In addition, X-ray photoelectron spectroscopy (XPS) measurements suggest that Sn (II) ions exist in the SnO2 samples when the reactions are stopped after a short time or when a relatively high concentration of Sn (II) is involved in the corresponding sol-gel reactions. Understanding this low-temperature growth of 3D SnO2 will provide new avenues for developing and producing high-performance, photofunctional nanomaterials via a cost-effective and scalable method.

Low temperature mullitization of oxime-modified aluminosiloxane by sol-gel process

2021 ◽  
pp. 1-9
Author(s):  
Ajay Saini ◽  
Dalip Singh ◽  
Banwari Lal Choudhary ◽  
Veena Dhayal
Keyword(s):  
Low Temperature ◽  
Sol Gel ◽  
Sol Gel Process

scholarly journals Low-temperature combustion of methane over graphene templated Co3O4 defective-nanoplates

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dian Gong ◽  
Gaofeng Zeng
Keyword(s):  
Low Temperature ◽  
Transition Metal Oxides ◽  
Active Oxygen Species ◽  
Low Cost ◽  
Thermal Reduction ◽  
Low Temperature Combustion ◽  
Solid Catalysts ◽  
Intermittent Feeding ◽  
Co Precipitation ◽  
Catalytic Combustion Of Methane

AbstractTransition metal oxides are the potential catalysts to replace noble-metal based catalyst for the catalytic combustion of methane due to the tolerable reactivity and low cost. However, these catalysts are challenged by the low temperature reactivity. Herein, the surface defective Co3O4 nanoplates are realized through a facile co-precipitation and thermal reduction method with the association of GO. The resultant catalysts (CoGO50) demonstrate a superior low-temperature reactivity for the methane oxidation to CO2 and H2O in comparison with the common Co3O4 catalyst. The reliable stability of CoGO50 catalyst was proved by 80 h testing with intermittent feeding of water vapor. The experimental analysis demonstrates that the presence of a small amount of GO significantly affects the catalysts in surface valence state, active oxygen species and surface oxygen vacancies through reacting with the cobalt oxide as a reductant. Moreover, GO plays as 2D confine template to form smaller and thinner nanoplates. This work provides a facile method to control the surface properties of catalyst not only for Co3O4 based catalysts but also for wider solid catalysts.

Increasing hydrophobicity of sol–gel hard coatings by chemical and morphological modifications

2005 ◽  
Vol 198 (1-3) ◽  
pp. 420-424 ◽  
Author(s):  
Linda Y.L. Wu ◽  
A.M. Soutar ◽  
X.T. Zeng
Keyword(s):  
Sol Gel ◽  
Hard Coatings
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