• 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.

• Macromolecular Research
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• v.15 no.3
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• pp.221-224
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• 2007

A silica-magnesium bisupport (SMB) was prepared by a sol-gel method for use as a support for a metal-locene/Ziegler-Natta hybrid catalyst. The prepared $rac-Et(Ind)_2ZrCl_2/TiCl_4$/MAO(methylaluminoxane)/SMB catalyst was applied to the copolymerization of ethylene with l-hexene using a variable triethylaluminum (TEA)/transition-metal (Ti) ratio and fixed MAO/transition-metal (Zr) ratio. The effect of the Al(TEA)/Ti ratio on the physical properties and chemical composition distributions (CCDs) of the ethylene-hexene copolymers produced by the hybrid catalyst was investigated. In the ethylene-hexene copolymers, two melting temperatures attributed to the metal-locene and Ziegler-Natta catalysts were clearly observed. The number of CCD peaks was increased from six to seven and the temperature region in which the peaks for the short chain branches of the ethylene-hexene copolymer were distributed became lower as the Al(TEA)/Ti ratio was increased from 300 to 400. Furthermore, the temperature regions corresponding to the lamellas in the copolymer became lower and those corresponding to the small lamellas in the copolymer became higher as the Al(TEA)/Ti ratio was increased from 300 to 400. In the copolymer produced with Al(TEA)/Ti = 500, however, only four CCD peaks were observed and the short chain branches were poorly distributed.

• Journal of Adhesion and Interface
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• v.17 no.4
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• pp.141-148
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• 2016

In this work, mesoporous silica (SBA-15) was synthesized via self-assembly process using triblock copolymer ($PEO_{20}PPO_{70}PEO_{20}$, P123) as template and tetraethyl orthosilicate (TEOS) as silica source under acidic condition. SBA-15 have high surface area ($704m^2g^{-1}$) and uniform pore size (8.4 nm) with well-ordered hexagonal mesostructure. Spiropyran-functionalized SBA-15 (Spiropyran-SBA-15) was synthesized via post-synthesis process using 3-(triethoxysilyl)propyl isocyanate (TESPI) and 1-(2-Hydroxyethyl)-3,3-dimethy-lindolino-6'-nitrobenzopyrylo-spiran (HDINS). Spiropyran-SBA-15 was produced with hexagonal array of mesopores without damage of mesostructre. Surface area and pore size of Spiropyran-SBA-15 were $651m^2g^{-1}$ and 8.0 nm, respectively. Optochemical properties of Spiropyran-SBA-15 was studied with chemical vapors such as EtOH, THF, $CHCl_3$, Acetone and HCl. Main peaks of photofluorescence of Spiropyran-SBA-15 exhibited blue shift in the range of 603.4~592.1 nm after exposure under EtOH, THF, $CHCl_3$, and Acetone vapors. Normalized peak intensities decreased in the range of 0.8~0.3. The main peak of photofluorescence of Spiropyran-SBA-15 showed significant blue shift of 592.1 nm after exposure under HCl vapor, while normalized peak intensity decreased to 0.1.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.106-106
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• 2003

최근 집적형 광소자, 레이저 재료, 자료 저장 또는 통신 기술부문에서 제어된 광학적 성질을 갖는 유기-무기 나노 복합체를 만드는 연구가 많은 관심과 주목을 받고 있다. 유기물인 PEG는 대다수의 금속염을 고정시키는 용매 역할을 하는 polymer로써 액체와 같은 특징을 나타내며 무기물인 silica의 network는 순수한 PEG 시스템보다 좋은 기계적 물성을 나타내며, 투명한 물질을 얻을 수 있게 해 준다. 이에 본 연구에서는 SiO2-PEG의 matrix에 우수한 광학적 성질을 지닌 europium을 doping하여 유기-무기 나노 복합막을 합성하여 europium의 농도와 PEG 분자량에 따른 구조적 및 광학적 성질을 알아보고자 한다.

• Proceedings of the Membrane Society of Korea Conference
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• 2008.05a
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• pp.164-164
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• 2008

• Macromolecular Research
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• v.17 no.9
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• pp.697-702
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• 2009

Mesoporous ethanesilica thin film was prepared using PEO-PLGA-PEO triblock copolymers as structure-directing agents and (1,2-bis(triethoxysilyl) ethane BTESE; bridged organosilicates) as inorganic precursors via one-step sol-gel condensation of ethanesilica precursors. The mesostructure of ethanesilica films is critically dependent on the processing experimental parameters after the hydrolyzed silica sol mixture was spin-cast. This study examined the effects of the block copolymer template/organosilica precursor ratio in the casting solution and aging period before calcination of the mesostructure. It was further demonstrated that mesoscopic ordering of organosilicate thin films is induced by the rearrangement of block copolymer template/organosilica hybrid during thermal decomposition of the PEO-PLGA-PEO triblock copolymer. The mesoporous structure and morphology were characterized by SAXS, TEM and solid-state NMR measurement.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05b
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• pp.176-179
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• 2004

Volatile organic compounds (VOCs) are emitted as gases from certain solids or liquids. VOCs include a variety of chemicals, some of which may have short- and long-term adverse health effects. Current technologies for the treatment of VOC contaminated off-gasses are expensive to operate and more cost effective technologies are needed.(omitted)

• Proceedings of the Membrane Society of Korea Conference
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• 2005.05a
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• pp.131-135
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• 2005

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.71-72
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• 2011

최근 스마트 휴대폰으로 대표되는 이동통신기기 산업의 빠른 성장으로 인하여 이들 기기를 보호하기 위한 표면 처리기술이 함께 발전하고 있다. 그중 대표적인 것이 나노기술을 융합한 보호막 도장 기술이다. 본 연구에서는 마그네슘 기판과 플라스틱 케이스 소재 위에 유무기 하이브리드 도장막을 형성시키고, 도장막의 실리카 조성에 따른 물리화학적 변화 거동을 관찰하였다. 특히, 실리카 나노입자가 첨가된 실리카 졸 용액과 UV 경화수지를 다른 비율로 혼합한 나노형 하이브리드 코팅용액을 사용하였으며, 딥 코팅과 스프레이 코팅법을 개별적으로 이용하여 형성한 유무기 하이브리드 코팅층의 경도와 내지문 특성을 중점적으로 조사하였다. 이러한 연구를 통하여 유무기 하이브리드 코팅층 형성에서 실리카 졸의 역할과 최적 물성확보를 위한 근거를 마련하였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.10a
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• pp.109-110
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• 2009

실리카와 폴리아닐린의 core-shell 복합체 나노입자를 실리카 나노입자 분산용액을 이용하여 제조하였다. 제조된 복합체 나노입자를 전기변색박막의 소재로 이용하기 위하여 알코올 용액에 분산하였고, 분산된 용액에 Tetraethoxysilane (TEOS)를 소량의 HCl 용액과 함께 첨가하여 코팅 용액을 제조하였다. 코팅 용액을 인듐주석산화물(ITO) 박막이 도포된 유리 기판위에 도포하고 열처리 하여 매우 높은 부착력을 갖는 전기변색박막을 얻을 수 있었다.