• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.422-422
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• 2009

Photocurable inorganic-organic hybrid materials were prepared from colloidal-silica nanoparticles synthesized through the solgel process and using acryl resin. The synthesized colloidal-silica nanoparticles had uniform diameters of around 20 nm, and they were organically modified, using methyl and methacryl functional silanes, for efficient hybridization with acryl resin. The organically modified and stabilized colloidal-silica nanoparticles could be homogeneously hybridized with aeryl resin without phase separation. The successfully fabricated hybrid materials exhibit efficient photocurability and simple film formation due to the photopolymerization of the organically modified colloidal-silica nanoparticles and acryl resin upon UV exposure. The fabricated hybrid films exhibit an excellent optical transmission of above 90% in the visible region as well as an enhanced surface smoothness of around 1 nm RMS roughness. In addition, the hybrid films exhibit improved thermal and mechanical characteristics, much better than those of acryl resin. More importantly, these photocurable hybrid materials fabricated through the synergistic combination of colloidal-silica nanoparticles with acryl resin are candidates for optical and electrical applications.

• Korean Journal of Materials Research
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• v.27 no.1
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• pp.12-18
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• 2017

Transparent organic-inorganic hybrid hard coating films were prepared by the addition of $SiO_2$ or $ZrO_2$, as an inorganic filler to improve the hardness property, filler was highly dispersed in the acrylic resin. To improve the compatibility in the acrylic resin, $SiO_2$ or $ZrO_2$ is surface-modified using various silanes with variation of the modification time and silane content. Depending on the content and kind of the modified inorganic oxide, transparent modified inorganic sols were formulated in acryl resin. Then, the sols were bar coated and cured on PET films to investigate the optical and mechanical properties. The optimized film, which has a modified $ZrO_2$ content of 4 wt% markedly improved in terms of the hardness, haze, and transparency as compared to neat acrylate resin and acrylate resin containing modified $SiO_2$ content of 8 wt%. Meanwhile, the low transparency and high haze of these films slowly appeared at $SiO_2$ content above 10 wt% and $ZrO_2$ content of 5 wt%, but the hardness values were maintained at 2H and 3H, respectively, in comparison with the HB of neat acrylate resin.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.793-794
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• 2008

• Journal of Adhesion and Interface
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• v.7 no.4
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• pp.32-38
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• 2006

A series of organic-inorganic hybrids, PCL/EP/$SiO_2$, involving epoxy resin and triethoxysilane-terminated polycaprolactone elastomer (PCL-TESi) were prepared via polymerization of diglycidyl ether of bisphenol A (DGEBA) with amine curing agent KB-2 and sol-gel process of PCL-TESi. The curing reactions were started from the initially homogeneous mixture of DGEBA, KB-2 and the PCL-TESi. The organicinorganic hybrids containing up to 4.95% (wt) of $SiO_2$ were obtained and characterized by FT-IR, transmission electron microscopy (TEM), differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA). It was experimentally shown that the swelling property in toluene, morphologies and thermal properties of the resulting hybrids were quite dependent on the contents of $SiO_2$. The crosslink network density decreases with increasing of the PCL-TESi. And in TEM, the phase separated morphology of these hybrids was found, which resulted from the coagulation of Si-O-Si networks resulting from $-Si(OC_2H_5)_3$ of PCL-TESi self-curing by hydrolytic silanol condensation, with the advancement of the curing reaction in the modified epoxy resin systems. Meanwhile, the change of the $SiO_2$ content made the morphologies changed from aggregated particles of Si-O-Si in the hybrid to nanocluster of interconnected Si-O-Si particles, then to aggregated Si-O-Si dispersing in the continuous cured epoxy phase again, and last to co-continuous interpenetrating network. The glass transition behavior of the hybrid material was cooperative motion of large chain segments, which were hindered by the inorganic Si-O-Si network. And in TG analysis, the characteristic temperature at 5% of weight loss was evidently increased from $120.5^{\circ}C$ of pure cured epoxy to $277.6^{\circ}C$ of 3.84% (wt) of $SiO_2$ modified epoxy due to the existence of Si-O-Si when PCL-TESi was added in the hybrid.

• Korean Chemical Engineering Research
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• v.46 no.2
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• pp.436-442
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• 2008

Organic-inorganic hybrid mesoporous anion-exchange resins were prepared for the adsorption of anions from aqueous solutions. The prepared samples were characterized using nitrogen adsorption-desorption measurements, Fourier transform infrared (FTIR) spectroscopy, and elemental analyses. Batch and kinetic experiments were performed to examine the anion-exchange performances of the prepared samples. Among the prepared samples, the hybrid mesoporous anion-exchange resins functionalized with tributylammonium groups showed higher adsorption capacities for perrhenate ions than did the resin functionalized with trimethylammonium groups. The surfactant, hexadecylamine, which had hydrophobic alkyl chains, also showed affinity for hydrophobic perrhenate anions.

• Journal of Power System Engineering
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• v.19 no.5
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• pp.38-44
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• 2015

The cold-rolled steel sheet for automobile is liable to corrosion, and will be painting in a variety of ways for the anticorrosive. This paper was coated on cold rolled steel (SPCC and SPFC590) for automobiles using five kinds of organic/inorganic hybrid solution. This was evaluated corrosion resistance and so on by the salt spray. Corrosion area was less according to increasing of curing time in 2 types of steel plate with 5 types of the coating solution. No.1 solution was showed the best corrosion resistance regardless of the kinds of the steel sheet. It is judged that the melamin hardner had the role of bridge between $SiO_2$ polysilicate and urethan resin. Other properties were excellent in all solution.

• Corrosion Science and Technology
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• v.17 no.2
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• pp.74-80
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• 2018

The electronic industries require environmentally-friendly and highly functional materials to enhance the quality of human life. Home appliances require insect repellent steels that work to protect household microwave ovens from incurring damage by insects such as fire ants and cockroaches in tropical regions. Thus, POSCO has developed new types of functional steels, coated with an array of organic-inorganic hybrid composites on the steel surface, to cover panels in microwave ovens and refrigerators. The composite solution uses a fine dispersion of hybrid solution with polymeric resin, inorganic and a pyrethroid additive in aqueous media. The hybrid composite solution coats the steel surface, by using a roll coater and is cured using an induction curing furnace on both the continuous galvanizing line and the electro-galvanizing line. The new steels were evaluated for quality performances, salt spray test for corrosion resistance and biological performance for both insect repellent and antimicrobial activity. The new steels with organic-inorganic composite coating exhibit extraordinarily biological functionalities, for both insect repellent and antimicrobial activities for short and long term tests. The composite-coating solution and experimental results are discussed and suggest that the molecular level dispersion of insecticide on the coating layer is key to biological functional performances.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.595-605
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• 2018

In recent years, researches on organic-inorganic coating films have conducted a nanocomposite system composed of organic resin matrices having excellent flexibility and chemical stability and inorganic materials having excellent mechanical properties. The o-phenylphenoxyethyl acrylate (OPPEA) used as the acrylate monomer has a high refractive index of 1.58, and the bisphenol A ethoxylate diacrylate (BAEDA) has a low refractive index but improves the chemical stability of the organic resin. In addition, zirconia used as an inorganic material exhibits excellent durability and optical properties. In this study, the BAEDA contents in acrylate monomer were controlled to produce a film with suitable optical transparency. And optimum conditions were established by comparing the changes in surface properties of PET films detected with pencil hardness tester, Abbe's refractometer, and UV-vis spectrophotometer. The hydrophobicity and the dispersibility of zirconia in acrylate monomer were much improved after modification with ${\gamma}$-methacryloxypropyltrimethoxysilane (MPS), which is a silane coupling agent. And the existence of ester C=O bond peak at $1716cm^{-1}$ introduced by MPS through FT-IR ATR spectrophotometer confirmed the completion of surface modification of zirconia with MPS. In addition, the presence of silicon atom on the surface modified zirconia was also proved using X-ray fluorescence spectrometer. When the photocurable hybrid coating was prepared by introducing chemically modified zirconia into acrylate monomer, the refractive index of this coated PET film was improved by 1.2%, compared to the only acrylate coated PET film. The homogeneous distribution of zirconia in acrylate coating layer on PET film was also identified through SEM/EDS mapping analysis technique.

• Journal of the Semiconductor & Display Technology
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• v.16 no.2
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• pp.19-26
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• 2017

The cure properties of ethoxysilyl bisphenol A type epoxy resin (Ethoxysilyl-DGEBA) systems with different hardeners were investigated, comparing with DGEBA and Diallyl-DGEBA epoxy resin systems. The cure kinetics of these systems were analyzed by differential scanning calorimetry with an isothermal approach, and the kinetic parameters of all systems were reported in generalized kinetic equations with diffusion effects. The Ethoxysilyl-DGEBA epoxy resin system showed lower cure conversion rates than DGEBA and Diallyl-DGEBA epoxy resin systems. The conversion rates of these epoxy resin systems with DDM hardener are lower than those with HF-1M hardener. It can be considered that the optimum hardener for Ethoxysilyl-DGEBA epoxy resin system is Phenol Novolac type. These lower cure conversion rates in the Ethoxysilyl-DGEBA epoxy resin systems could be explained by the retardation of reaction molecule movements according to the formation of organic-inorganic hybrid network structure by epoxy and ethoxysilyl group in Ethoxysilyl- DGEBA epoxy resin system.

• Journal of Adhesion and Interface
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• v.15 no.2
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• pp.69-76
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• 2014

Two kinds of epoxy-functionalized alkoxysilane (EAS) compounds (EAS-MS and EAS-ES) were successfully synthesized through the reaction between epoxy resin (YD-128) and aminopropyl trimethoxysilane (APTMS) or aminopropyl triethoxysilane (APTES). By the hydrolysis-polycondensation reaction of EAS compounds with 3-Glycidyloxypropyl trimethoxysilane (GPTMS) and Tetraethyl orthosilicate (TEOS), silica/epoxy nanohybrids could be prepared at various compositions of EAS to GPTMS/TEOS. Prepared nanohybrids were yellow transparent and miscible with various organic solvents. By the reaction silica/epoxy nanohybrids with curing agents (TETA or acrylic acid), cured hybrids films could be obtained. These cured films showed higher thermal stability and mechanical property compared to cured neat epoxy resin. TEM and AFM images showed formation of nano-sized silica nanoparticles within cured hybrid films.