• Journal of the Society of Cosmetic Scientists of Korea
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• v.37 no.3
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• pp.227-236
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• 2011

The new sunscreen agent, methoxycinnamidopropyl polysilsesquioxane, is manufactured as polymeric particles with an organic/inorganic hybrid composition. We have already reported the manufacturing method, physical properties, and sunprotection effects of methoxycinnamidopropyl polysilsesquioxane. In this study, we evaluated the photochemical properties and photostabilities of methoxycinnamidopropyl polysilsesquioxane that has the same functional group as a typical organic sunscreen agent, ethylhexyl methoxycinnamate (EHMC). Using the correlation of UV absorbance and fluorescence, we studied photostabilizers to enhance the photostability of methoxycinnamidopropyl polysilsesquioxane. Finally, we confirmed that octocrylene, ethylhexyl methoxycrylene, and bis-ethylhexyloxyphenol methoxyphenyl triazine were good photostabilizers for methoxycinnamidopropyl polysilsesquioxane.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.4
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• pp.53-58
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• 2018

Since the scaling-down of IC devices has been reached to their physical limitations, several innovative packaging technologies such as 3D packaging, embedded packaging, and fan-out wafer level packaging (FOWLP) are actively studied. In this study the fabrication of organic-inorganic dielectric material was evaluated for the use of multi-structured redistribution layers (RDL) in FOWLP. Compared to current organic dielectrics such as PI or PBO an organic-inorganic hybrid dielectric called polysilsesquioxane (PSSQ) can improve mechanical, thermal, and electrical stabilities. polysilsesquioxane has also an excellent advantage of simultaneous curing and patterning through UV exposure. The polysilsesquioxane samples were fabricated by spin-coating on 6-inch Si wafer followed by pre-baking and UV exposure. With the 10 minutes of UV exposure polysilsesquioxane was fully cured and showed $2{\mu}m$ line-pattern formation. And the dielectric constant of cured polysilsesquioxane dielectrics was ranged from 2.0 to 2.4. It has been demonstrated that polysilsesquioxane dielectric can be patterned and cured by UV exposure alone without a high temperature curing process.

• Membrane Journal
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• v.15 no.1
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• pp.1-7
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• 2005

Polymer electrolyte membranes containing polysilsesquioxane (PSQ) spheres were prepared with the blend of sulfonated poly(ether ether ketone) (SPEEK) (60%) and poly(ether sulfone) (PES) (40%). The amount of PSQ spheres was fixed at 10 wt%. The prepared polymer electrolyte membranes were characterized in terms of methanol permeability, proton conductivity, and ion exchange capacity. In all cases, both methanol permeability and proton conductivity of the polymer electrolyte membranes containing PSQ spheres were lower than the values of Nafion 117 and higher than those of SPEEK/PES (6:4) blend without PSQ spheres. The experimental results indicated that the polymer electrolyte membranes containing MS64 and VTMOS spheres were the best choice in terms of the ratio of proton conductivity to methanol permeability.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.1
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• pp.47-55
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• 2010

UV-screening agents have some adverse effects that raise consumers' concern. The organic agents often cause irritation and may penetrate into human body while the inorganic agents raise aesthetic issues because they often turn opaque. Organic agents with high molecular weights and nano-sized inorganic agents have been developed respectively to minimize transdermal intrusion into human body and suppress turning opaque. Recently, we reported preparation of powdery UV-screening agents made of polysilsesquioxane, an organic-inorganic hybrid material. Powders would not penetrate into epidermis and organic-inorganic hybrid nature would suppress the opaqueness problem. In this study, we continued our research on this powdery polysilsesquioxane UV-screening agent, SESQUV, regarding its chemical composition, its synergic UV-screening effects when mixed with other organic agents, and its applicability in practical formulation. Results showed SESQUV was promising UV-screening agents useful in sunscreen formulation.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.31 no.1 s.49
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• pp.65-71
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• 2005

A silsesquioxane precursor that contains p-methoxycinnamoyl group was synthesized to produce UV absorbing spherical polysilsesquioxane (PSQ) spheres with diameters of 10nm to a few ${\mu}m$ under different conditions. A dispersion of $10wt\%$ in Vaseline of these PSQ spheres with diameters of approximately $0.6{\mu}m$ showed SPF values of 5.7 and the identical dispersion did not turn white when applied to human hands. These UV absorbing PSQ spheres showed higher boosting effect of sun protection factor (SPF) than the well known UV blocking octyl methoxycinnamate (OMC). The results indicated that the PSQ spheres with p-methoxycinnamoyl group should be useful as the ingredients in UV screening functional cosmetics without causing allergies and whitening.

• Applied Chemistry for Engineering
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• v.32 no.4
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• pp.467-471
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• 2021

A ladder-like polysilsesquioxane (LPMA64) functionalized with a crosslinkable group was synthesized and used for the preparation of organic-inorganic hybrid gel polymer electrolytes through a thermal crosslinking process of the liquid electrolytes. A small weight percent of LPMA64 polymer crosslinker (5 wt%) was able to form a well-developed network structure, resulting in good dimensional stability with high ionic conductivity. The lithium-sulfur batteries fabricated with organic-inorganic hybrid gel polymer electrolytes exhibited stable C-rate and cycling performance with excellent Coulombic efficiency due to the alleviated lithium polysulfide shuttling effect during prolonged cycling. The result demonstrates that the organic-inorganic hybrid gel polymer electrolytes could be a promising candidate electrolyte for application in lithium-sulfur batteries.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.37 no.3
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• pp.247-256
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• 2011

Existing organic UV protection materials seem to be problematic due to their penetration and irritation to skin. Inorganic UV protection materials are also at issue for safety of their nano-type transformation. Therefore, the recent studies of UV protection materials have been focused not only on the effectiveness but also on their safety. One of the UV protection materials in study which have higher safety is the organic-inorganic conjugation type UV protection material. Previously, we have reported the manufacturing process, physical property and UV protection efficiency of methoxychinnamidoprophy poloysilsesquixan as a new cross-linked polymer type UV protection material. In this study, we have evaluated the effect of the methoxychinnamidoprophy poloysilsesquixan on embryo-fetal development in SD rats. This study is expected to show some definite information related to the effect on pregnancy or embryo-fetal abnormality in case of the clinical exposure of the methoxychinnamidoprophy poloysilsesquixan.

• Macromolecular Research
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• v.16 no.4
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• pp.353-359
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• 2008

Spheres of silicon resins with different compositions were prepared in one-step reaction from mixtures of water and water-insoluble precursors of polysiloxanes (PSO) and polysilsesquioxanes (PSQ) using different amines as catalysts. The presence of PSO and PSQ in the spheres was confirmed by their mechanical properties and FTIR spectroscopy. Spheres of pure PSO were obtained from only dimethoxymethylvinylsiloxane (DMMVS) and 3-mercaptopropylmethyldimethoxysilan (MPMDMS) when the reaction was induced with appropriate catalysts. DMMVS and MPMDMS always gave the most promising results regarding the formation of discrete solid spheres with the minimum tendency to form monolithic solids or fluid-like, premature products. The spheres were characterized by optical microscopy, scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy. The mixtures containing larger amounts of PSO precursors commonly gave lower yields and softer spheres.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.7
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• pp.3252-3260
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• 2012

2,2'-Bipyridinium chlorochromate[$C_{10}H_8N_2HCrO_3Cl$] was synthesized by the reaction of 2,2'- bipyridine with chromium(VI) trioxide in 6M HCl. The structure was characterized by IR and ICP analysis. The oxidation of benzyl alcohol using 2,2'-bipyridinium chlorochromate in various solvents showed that the reactivity increased with the increase in the order of the dielectric constant(${\varepsilon}$), in the order: cyclohexene< chloroform$p-CH_3$, H, m-Br, $m-NO_2$) in N,N'-dimethylformamide. Electron-donating substituents accelerated the reaction, whereas electron acceptor groups retarded the reaction. The Hammett reaction constant(${\rho}$) was -0.64(303K). The oxidation reactivity of alcohols can be a useful factor to study about physical properties such as thermal stability, when the polysilsesquioxane solution is ready for an applying coating agent. The observed experimental data was used to rationalized the hydride ion transfer in the rate-determining step.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.03a
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• pp.104-104
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• 2003

다양한 구조를 갖는 polysilsesquioxane은 열적, 전기적, 기계적 성질이 우수하여 차세대 고집적 반도체용 저 유전율 층간 절연막 재료로 부각되고 있으며, 유/무기 하이브리드 재료로 많은 연구 대상이 되고 있다. 그러나 PMSSQ(polymethylsilsesquioxane)는 취성으로 인한 반도체 제조의 CMP 공정에서 미세 크렉 발생의 위험이 있으므로 막의 인성 강화가 요구되고 있다. 이를 위하여 PMSSQ의 취성을 보완하기 위한 목적으로 선형 분자인 dimethylsiloxane을 10-20mo1% 도입하고자 하였다. 이때 도입된 dimethylsiloxane기가 PMSSQ에 균일하게 분포하지 않으면 실리콘 기판에 코팅 후 약 43$0^{\circ}C$의 열처리 공정 중에 열분해 되는 위험이 있다. 이에 따라 본 연구에서는 dimethylsiloxane기의 열분해에 의한 문제를 최소화하기 위하여 출발 물질인 MTMS(methyltrimethoxysilane)와 DMDMS(dimethyldimethoxysilane)과의 가수분해 속도차이를 고려한 단계(step) 반응법과 MTMS 와 DMDES(dimethyldiethoxysilane)를 사용한 리간드 교환법(ligand exchange)으로 dimethylsiloxane이 PMSSQ에 도입된 공중합체를 합성하였다. 각 합성 방법에 따라 합성된 공중합 PMSSQ의 특성을 TGA, TG-IR, $^1$H-NMR, $^{29}$ Si-NMR과 in-situ IR을 통하여 분석하였다. 또한 dimethylsiloxane 도입 양 및 상기 제조 방법에 따라 합성한 공중합체를 Si 기판위에 코팅하여 43$0^{\circ}C$에서 열처리한 후 코팅막의 강도, 두께 및 굴절율 변화를 ellipsometry 와 nanoindenter로 분석하였다.