• Applied Chemistry for Engineering
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• v.20 no.4
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• pp.370-374
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• 2009

A double-layer optical sensing membrane has been fabricated to measure the concentration of dissolved oxygen (DO) and pH value simultaneously. (tris(4,7-diphenyl-1,10-phenanthroline (Rudpp) ruthenium(II)) as a DO sensitive dye has been mixed in the methyl trimethoxy silane (MTMS) sol-gel solution and coated onto one well in a 24-well microtiter plate. On the DO-sensing layer the GA (3-glycidoxypropyl trimethoxy silane (GPTMS), 3-aminopropyl trimethoxy silane (APTMS)) sol-gel solution mixed with 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS) has been coated and used to measure pH values. The double-layer sensing membrane was affected by ionic strength and temperature. The double-layer sensing membrane for DO and pH has been applied to online monitor in microorganism cultivation processes and showed a good performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.3
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• pp.1479-1487
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• 2011

In the field of the entire electronic component industry including mobile IT products, the importance of a versatile package with the multifunctional or high capacity memories is gradually increased. Multi Chip Package which has several chips in a single package is frequently used for that purpose. In MCP, epoxy adhesive films play a major role in adhesion between the chips or between chip and substrate. A series of silane coupling agents with a functional group such as epoxy, amine, mercaptan, and isocyanate were applied to the epoxy adhesives and material properties such as wettability and reliability of the adhesives were investigated. From the results, the silane coupling agent with an epoxy functional group showed highest wettability and peel strength in epoxy adhesive. For those reasons, it lead to a superior reliability in the epoxy adhesive against interfacial fracture behaviors through moisture resistance test.

• Applied Chemistry for Engineering
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• v.29 no.1
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• pp.37-42
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• 2018

In order to increase the compatibility of polypropylene (PP) and kenaf fiber (KF) felt, PP/KF and PP/KF/polyurethane (PU) felt composites were prepared by treating KF with three kinds of silane coupling agents. The concentration of silane coupling agents was fixed at 1 wt%. The chemical reaction between KF and silane coupling agents was confirmed by the existence of Si-O-Si and Si-O-C functional group bands appeared on FT-IR and X-ray photoelectron spectra (XPS). Thermal properties of PP/KF composites were investigated by DSC and TGA, and the thermal stability of PP/KF composites with treated KF increased. Based on tensile, flexural and impact properties of PP/KF and PP/KF/PU composites, 1-2 wt% of (3-aminopropyl)triethoxysilane (APS) contents were the optimum formulation as a compatibilizer. The tensile and flexural strength of the felt composites treated with the silane coupling agents were improved. This is mainly due to the improvement in the compatibility between PP and KF, which was confirmed by SEM images of the fractured surfaces after tension tests.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.6
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• pp.291-298
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• 2012

Carbamoylphosphate (CMPO) [CMPO analogue; 2-(diphenylphosphoryl)-N-(3-(triethoxysilyl)propyl)acetamide]silane, as a functional self-assembled molecules, grafted mesoporous silicates were prepared by simple hydrolysis and condensation reaction. Pore sized tailored mesoporous silicates such as MCM-41, SBA-15, or amorphous silica nanoparticles were adopted as host materials. The surface area of ordered mesoporous silicates was ranged from 680 $m^2/g$ to 1310 $m^2/g$ with different pore diameters that estimated to be ca. 2.3~9.1 nm by BJH method. Among the OMMs host materials, SBA-15(II) has higher loading ratio (~35 wt%) of CMPO derivative than other OMMs. Accessibility to CMPO silane functional groups in the surface of mesoporous silicas was studied by lanthanide ions sorption experiments. All of the CMPO modified OMMs favors the smaller Eu(III) and Nd(III) cations than La(III) for relative larger ionic radius.

• Applied Chemistry for Engineering
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• v.31 no.2
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• pp.230-236
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• 2020

In this study, an adhesive tape with water and impact resistance for mobile devices was developed using a UV-curable urethane acrylate based polymer as a substrate. The substrate fabricated by UV-curable materials shows hydrophobicity and poor wettability, which significantly deteriorates the interface-adhesions between the substrate and acrylic adhesive. In order to improve the interface adhesion, 3-glycidoxy-propyl trimethoxysilane (GPTMS), a silane coupling agent having epoxy functional groups, was selected and incorporated into UV-curable urethane acrylate based polymer resins in various contents. The changes of the chemical composition according to the contents of GPTMS was studied with Fourier-transform infrared spectroscopy (FT-IR), energy-dispersive X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS) to know the surface bonding properties. Also mechanical properties of the substrate were characterized by tensile strength, gel fraction and water contact angle measurements. The peel strengths at 180° and 90° were measured to compare the adhesion between the substrate and adhesive according to the silane coupling agent contents. The mechanical strength of the urethane acrylate adhesive tape decreased as the silane coupling agent increased, but the adhesion between the substrate and adhesives increased remarkably at an appropriate content of 0.5~1 wt%.

• Polymer(Korea)
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• v.36 no.6
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• pp.816-821
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• 2012

In this study, silane-crosslinked proton exchange membranes were prepared by step-wise radiation grafting of styrene and 3-(trimethoxysilyl)propyl methacrylate (TMSPM) onto an poly(ethylene-co-tetrafluoroethylene) (ETFE) film and followed by sol-gel processing and sulfonation. The sequentially grafted films with styrene to provide the proton conductivity and TMSPM to form the crosslinked structure were prepared by different grafting order. The structural changes and thermal properties of the prepared films were investigated by FTIR and TGA, respectively. After the introduction of sulfonic acid functional groups, the distributions of sulfonic acid group and silicon atoms at the inside of the sulfonated membranes were analyzed by SEM-EDX.

• Macromolecular Research
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• v.15 no.2
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• pp.147-153
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• 2007

Hyperbranched polysiloxysilanes (HBPSs), with a variety of terminal functional groups (vinyl, epoxy, carboxyl and hydroxyl), were synthesized by the self-polymerization of an $AB_3$ type monomer of tris(dimethylvinylsiloxy) silane, with subsequent end-functionalizations, such as epoxidation and radical addition reaction, respectively. The ratio of the $\alpha-and$ $\beta-addition$ linkages in the HBPS polymerized by hydrosilylation of the $AB_3$ monomer was found to be approximately 1 to 3. The thermal stability and solubility were affected by the terminal functional groups.

• Food Science and Biotechnology
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• v.18 no.3
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• pp.766-770
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• 2009

Hot water extracts of Camellia japonica flower buds were found to have the higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity than the other solvent extracts. Five phenolic compounds were isolated and purified from the ethyl acetate soluble-neutral fraction of hot water extracts by Sephadex LH-20 column chromatography and octadecyl silane-high performance liquid chromatography using the guided assay of DPPH radical scavenging. Based on mass spectrometer and nuclear magnetic resonance, the isolated compounds were identified as p-hydroxybenzaldehyde (1), vanillin (2), dehydroxysynapyl alcohol (3), 7S,7'S,8R,8'R-icariol $A_2$ (4), and (-)-epicatechin (5). Four compounds (1-4) except for 5 were newly identified in this plant. Their DPPH radical scavenging activities as 50% scavenging concentration decreased in order to 5 $(20\;{\mu}M)>{\alpha}-tocopherol$ $(29\;{\mu}M)>4$ $(67\;{\mu}M)>3$ $(72\;{\mu}M)>1=2$ ($>250\;{\mu}M$). These results indicate that the antioxidant effect of the hot water extract of C. japonica flower buds may partially due to 5 isolated phenolic compounds.

• Clean Technology
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• v.27 no.2
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• pp.124-131
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• 2021

As declarations of carbon neutrality are spreading throughout the world, much research is being conducted on biodegradable polymers. In this study, nanocellulose, which comprises the largest amount of natural polymer currently available in the world, was proposed as a substitute for non-biodegradable polymers. We chose to modify the surface functional group of crystalline nanocellulose using glycidoxypropyl trimethoxysilane (GPTMS), which is a silane coupling agent, and the product was then used to form a film with low density polyethylene (LDPE). We then conducted measurements using a Fourier transform infrared spectrophotometer (FT-IR) in addition to measuring hydrophilic/lipophilicity of the surface functional group modification of crystalline nitrocellulose as well as that of a polymer composite using the hybrid nanocellulose (H-NC). For compatibility with petroleum-based polymers, the best tensile strength and transparency was found when the H-NC was reacted at pH 14 and 1 wt% compared with LDPE. From the test results, we found that it is possible to modify the surface functional groups of nanocellulose using a silane coupling agent. In addition, the high compatibility of nanocellulose with petroleum-based polymers is expected to help in reaching carbon neutrality by reducing the use of fossil fuels.

• Korean Journal of Materials Research
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• v.33 no.1
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• pp.1-7
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• 2023

The physical and antibacterial properties of ophthalmic lenses fabricated by copolymerization with hydrogel monomers using two types of graphene were measured, and their usability as contact lens materials was analyzed. For polymerization, silicone monomers, including SID-OH, 3-(methacryloxy)propyl tris(trimethylsiloxy)silane, and decamethylcyclopentasiloxane, were used, and N,N-dimethylacetamide, ethylene glycol dimethacrylate as a crosslinking agent, and azobisisobutyronitrile as an initiator were added. Also, graphene oxide nanoparticle (GON) and graphene nanoplate (GNP) were used as an additive, and the physical properties of the lenses fabricated after copolymerization were evaluated. The fabricated lenses satisfied the basic physical properties of general hydrogel contact lenses and showed the characteristics of lenses with high water content, and the disadvantage of very weak durability, due to low tensile strength. However, it was confirmed that the tensile strength and antibacterial properties were greatly improved by adding GON and GNP. With GON, the oxygen permeability and refractive index of the fabricated lenses were slightly improved. Therefore, it was determined that the graphene materials used in this study can be used in various ways as a contact lens material.