Factors towards Pencil Scratch Resistance of Protective Sol-Gel Coatings on Polycarbonate Substrate

2006 ◽  
Vol 312 ◽  
pp. 339-344 ◽  
Author(s):  
Edmund Chwa ◽  
Linda Wu ◽  
Z. Chen
Keyword(s):  
Fracture Toughness ◽  
Colloidal Silica ◽  
Elasticity Modulus ◽  
Sol Gel ◽  
Hardness Test ◽  
Scratch Resistance ◽  
Indentation Hardness ◽  
Pencil Hardness ◽  
Film Cracking ◽  
Polycarbonate Substrate

Sol-gel coatings with different amount of colloidal silica were prepared on polycarbonate substrate. The scratch resistance was measured by the pencil hardness test based on ASTM Standard D3363-00. The indentation hardness, elasticity modulus and fracture toughness of the coatings were also characterized and correlated to the observed pencil hardness. The scratch failure was found to be due to film cracking at the trailing end. Based on such an observation, the current analysis points out that the main factors towards scratch resistance are elasticity modulus, thickness and fracture toughness of the film.

Fabrication of Anti-Reflective Coatings on Solar Collector Tubes

2011 ◽  
Vol 306-307 ◽  
pp. 125-129 ◽  
Author(s):  
Yu Chao Niu ◽  
Guo Wei Huang ◽  
Ying Chen ◽  
Wen Wen Dou ◽  
De Ming Sun ◽  
...  
Keyword(s):  
Solar Collector ◽  
Sol Gel ◽  
Scratch Resistance ◽  
Scanning Microscope ◽  
Acid Base ◽  
Pencil Hardness ◽  
Reflective Coating ◽  
Atomic Force ◽  
Relative Standard ◽  
Reflective Coatings

In order to reduce the reflection of solar collector cover tube and improve its transmissivity, a kind of SiO2anti-reflective coating on the cover tube was prepared using acid-base two-step sol-gel method. The surface morphology of the anti-reflective coating was observed using atomic force microscope and electronic scanning microscope. The scratch resistance of the coating was tested using pencil hardness apparatus. The transmissivity and anti-impact properties of the cover tube coated with the coating were measured respectively by means of the spectrophotometer and the relative standard method. The results showed that the anti-reflective coating possesses a higher scratch resistance and the coated cover tube has good transmissivity and anti-impact.

Development of the scratch resistance on acrylic sheet with basic colloidal silica (SiO2)-methyltrimethoxysilane (MTMS) nanocomposite films by sol-gel technique

2011 ◽  
Vol 90 (4) ◽  
pp. 888-896 ◽  
Author(s):  
Rojcharin Chantarachindawong ◽  
Wasutap Luangtip ◽  
Pongpan Chindaudom ◽  
Tanakorn Osotchan ◽  
Toemsak Srikhirin
Keyword(s):  
Colloidal Silica ◽  
Sol Gel ◽  
Scratch Resistance ◽  
Nanocomposite Films ◽  
Acrylic Sheet ◽  
Gel Technique

Study the Effect of Coating Thickness from Silica Nanocomposite Deposited on Poly(Methyl Methacrylate) Sheets via Spray Coating Technique

2017 ◽  
Vol 895 ◽  
pp. 79-82 ◽  
Author(s):  
Taksorn Jirathampradhab ◽  
Siraprapa Lhosupasirirat ◽  
Pisist Kumnorkaew ◽  
Thananan Akhadejdamrong ◽  
Pichet Rojanapitayakorn ◽  
...  
Keyword(s):  
Coating Thickness ◽  
Colloidal Silica ◽  
Spray Deposition ◽  
Sol Gel ◽  
Spray Coating ◽  
Hard Coating ◽  
Pencil Hardness ◽  
Coating Solution ◽  
Pmma Surface ◽  
Surface Modified

The development of hard coating based on colloidal silica nanoparticles on polymethyl methacrylate (PMMA) sheet was reported. The colloidal silica was surface-modified with methyltrimethoxysilane (MTMS) and formulated to hard coating solution via sol-gel process. The hard coating solution was applied to PMMA surface by spray deposition technique. Spraying process was carried out from spray nozzle outlet diameter of 0.35 mm and air compress pressure at 0.2 MPa with nozzle to substrate distance at 10 cm. The different coating thicknesses were obtained by adjusting the amount of coating applied. The optimal coating thickness that gives the highest pencil-hardness at 7H and 100% adhesion for adhesion tape test is 10 μm.

Effect of Aging Temperature on Fracture Toughness of Cast Austenitic Stainless Steel

2015 ◽  
Author(s):  
Yasufumi Miura ◽  
Masato Yamamoto
Keyword(s):  
Fracture Toughness ◽  
Stainless Steel ◽  
Austenitic Stainless Steel ◽  
Aging Temperature ◽  
Charpy Impact ◽  
Hardness Test ◽  
Charpy Impact Test ◽  
Test Material ◽  
Indentation Hardness ◽  
Fracture Toughness Test

In this study, fracture toughness of cast austenitic stainless steel aged at 300–450°C for up to 15000 h were investigated using fracture toughness test, Charpy impact test and indentation hardness test. Test material was statically casted grade CF-3M stainless steel. As a result of the tests, it was found that the fracture toughness and the Charpy absorbed energy tended to decrease with the increase of aging time. However, the behavior of thermal embrittlement varied at each aging temperature. In particular, the fracture toughness of the specimens aged at 300°C was almost the same as that of the unaged specimens. At elevated temperature, the differences of the fracture toughness between unaged specimens and aged specimens were smaller than that of tested at room temperature.

Phase separation in sol gel-derived ceramic films of silica-zirconia, alumina-zirconia, and titania-zirconia system

1994 ◽  
Vol 52 ◽  
pp. 646-647
Author(s):  
J. Tong ◽  
L. Eyring
Keyword(s):  
Fracture Toughness ◽  
Phase Separation ◽  
Sol Gel ◽  
Great Influence ◽  
High Strength ◽  
Chemical Durability ◽  
Separation Method ◽  
Toughening Mechanism ◽  
Ceramic Films ◽  
Zirconia Toughened Alumina

There is increasing interest in composites containing zirconia because of their high strength, fracture toughness, and its great influence on the chemical durability in glass. For the zirconia-silica system, monolithic glasses, fibers and coatings have been obtained. There is currently a great interest in designing zirconia-toughened alumina including exploration of the processing methods and the toughening mechanism.The possibility of forming nanocrystal composites by a phase separation method has been investigated in three systems: zirconia-alumina, zirconia-silica and zirconia-titania using HREM. The morphological observations initially suggest that the formation of nanocrystal composites by a phase separation method is possible in the zirconia-alumina and zirconia-silica systems, but impossible in the zirconia-titania system. The separation-produced grain size in silica-zirconia system is around 5 nm and is more uniform than that in the alumina-zirconia system in which the sizes of the small polyhedron grains are around 10 nm. In the titania-zirconia system, there is no obvious separation as was observed in die alumina-zirconia and silica-zirconia system.

UV Curable Organic-Inorganic Hybrid Materials

2000 ◽  
Vol 628 ◽  
Author(s):  
Guang-Way Jang ◽  
Ren-Jye Wu ◽  
Yuung-Ching Sheen ◽  
Ya-Hui Lin ◽  
Chi-Jung Chang
Keyword(s):  
Hybrid Materials ◽  
Colloidal Silica ◽  
Sol Gel ◽  
Solution Ph ◽  
Uv Curable ◽  
Inorganic Hybrid ◽  
Degradation Temperature ◽  
Sol Gel Process ◽  
The Stability ◽  
Thermal Degradation Temperature

This work successfully prepared an UV curable organic-inorganic hybrid material consisting of organic modified colloidal silica. Applications of UV curable organic-inorganic hybrid materials include abrasion resistant coatings, photo-patternable thin films and waveguides. Colloidal silica containing reactive functional groups were also prepared by reacting organic silane and tetraethyl orthosilicate (TEOS) using sol-gel process. In addition, the efficiency of grafting organic moiety onto silica nanoparticles was investigated by applying TGA and FTIR techniques. Experimental results indicated a strong interdependence between surface modification efficiency and solution pH. Acrylate-SiO2 hybrid formation could result in a shifting of thermal degradation temperature of organic component from about 200°C to near 400°C. In addition, the stability of organic modified colloidal silica in UV curable formula and the physical properties of resulting coatings were discussed. Furthermore, the morphology of organic modified colloidal silica was investigated by performing TEM and SEM studies‥

Characterization of New Ionically Conducting Peo-Based Networks by Diffusion, Elasticity Modulus and Ionic Conductivity Measurements

1992 ◽  
Vol 293 ◽  
Author(s):  
Herve Cheradame ◽  
F. Desbat ◽  
P. Mercier-Niddam ◽  
S. Boileau
Keyword(s):  
Diffusion Coefficient ◽  
Ionic Conductivity ◽  
Elasticity Modulus ◽  
Sol Gel ◽  
Cation Transport ◽  
Lithium Cation ◽  
Conductivity Measurements ◽  
Conducting Materials ◽  
Diffusion Studies

AbstractIonically conducting materials containing PEO were prepared from telechelic di(methyl-diethoxy-silane) PEO, synthesized by the hydrosilylation of telechelic diallyl-PEO with methyldiethoxysilane. The network is obtained by the usual sol-gel chemistry. Then, it is filled with LiClO4 by diffusion of the salt and further drying. A comparison is made with the same kind of materials crosslinked using urethane chemistry. Diffusion studies show that the diffusion coefficient of solvent is similar for both types of materials, whilst the ionic conductivity is higher for the networks crosslinked with siloxane bonds. An experiment of diffusion of LiClO4 without solvent showed that this salt has a diffusion coefficient of the order of 2.10-8 cm2.sec-1 at 34°C. The conductivity calculated from this determination is compatible with the mechanism of lithium cation transport by the diffusion of salt molecules. Elasticity modulus measurements show that the salt aggregates are essentially located within the crosslinks at low concentration, but also in the PEO chains for salt concentrations higher than 1 mol/l.

scholarly journals Hard Coating Materials Based on Photo-Reactive Silsesquioxane for Flexible Application: Improvement of Flexible and Hardness Properties by High Molecular Weight

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1564
Author(s):  
Jong Tae Leem ◽  
Woong Cheol Seok ◽  
Ji Beom Yoo ◽  
Sangkug Lee ◽  
Ho Jun Song
Keyword(s):  
Molecular Weight ◽  
Surface Morphology ◽  
High Molecular Weight ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Coating Materials ◽  
Pencil Hardness ◽  
Coated Film ◽  
Flexible Application

EPOSS of polyhedral oligomeric silsesquioxanes (POSS) mixture structure and LPSQ of ladder-like polysilsesquioxane (LPSQ) structure were synthesized via sol–gel reaction. EPSQ had a high molecular weight due to polycondensation by potassium carbonate. The EPSQ film showed uniform surface morphology due to regular double-stranded structure. In contrast, the EPOSS-coated film showed nonuniform surface morphology due to strong aggregation. Due to the aggregation, the EPOSS film had shorter d-spacing (d1) than the EPSQ film in XRD analysis. In pencil hardness and nanoindentation analysis, EPSQ film showed higher hardness than the EPOSS film due to regular double-stranded structure. In addition, in the in-folding (r = 0.5 mm) and out-folding (r = 5 mm) tests, the EPSQ film did not crack unlike the EPOSS coated film.

scholarly journals Tough metal-ceramic composites with multifunctional nacre-like architecture

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Erik Poloni ◽  
Florian Bouville ◽  
Christopher H. Dreimol ◽  
Tobias P. Niebel ◽  
Thomas Weber ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Sol Gel ◽  
Ceramic Composites ◽  
High Fracture Toughness ◽  
Processing Route ◽  
High Fracture ◽  
Metal Ceramic ◽  
Attractive Option ◽  
Brick And Mortar ◽  
Robotic Applications

AbstractThe brick-and-mortar architecture of biological nacre has inspired the development of synthetic composites with enhanced fracture toughness and multiple functionalities. While the use of metals as the “mortar” phase is an attractive option to maximize fracture toughness of bulk composites, non-mechanical functionalities potentially enabled by the presence of a metal in the structure remain relatively limited and unexplored. Using iron as the mortar phase, we develop and investigate nacre-like composites with high fracture toughness and stiffness combined with unique magnetic, electrical and thermal functionalities. Such metal-ceramic composites are prepared through the sol–gel deposition of iron-based coatings on alumina platelets and the magnetically-driven assembly of the pre-coated platelets into nacre-like architectures, followed by pressure-assisted densification at 1450 °C. With the help of state-of-the-art characterization techniques, we show that this processing route leads to lightweight inorganic structures that display outstanding fracture resistance, show noticeable magnetization and are amenable to fast induction heating. Materials with this set of properties might find use in transport, aerospace and robotic applications that require weight minimization combined with magnetic, electrical or thermal functionalities.

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