• Polymer(Korea)
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• v.36 no.3
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• pp.372-379
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• 2012

In this study, we treated silica nanoparticles with bis[3-(trimethoxysilyl)propyl]amine (BTMA) silane coupling agent to modify their surfaces. We investigated the effects of BTMA hydrolysis time, BTMA concentration and BTMA treatment time on the degree of silanization reaction of silica nanoparticles. We used Fourier transform infrared spectroscopy (FTIR), elemental analysis (EA) and solid state cross-polarization magic angle spinning (CP/MAS) nuclear magnetic resonance spectroscopy (NMR) to obtain quantitative data. We found the decrease of isolated Si-OH peak intensity at 3747 $cm^{-1}$ and the increase of $-CH_2 $stretching and bending peaks with increasing hydrolysis time, concentration and treatment time of BTMA. EA analysis results also supported this trend. We found a strong effect of BTMA concentration on the degree of silanization of the silica particles, but weak effects of the hydrolysis time and the treatment time.

• Applied Chemistry for Engineering
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• v.17 no.6
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• pp.580-585
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• 2006

UV-thermal dually curable coating materials were prepared by the sol-gel method. Nano-sized colloidal boehmite was treated with various organo silane coupling agents. These materials could be well dispersed in various alcohols and relatively polar organic solvents such as tetrahydrofuran and acetonitrile. The coating films were prepared by a spin coating method on various substrates, which were characterized by FT-IR, Si/Al CP MAS NMR spectra, UV-Vis spectrophotometer, FE-SEM, Taber abraser, haze meter, and pencil hardness tester. The effects of molar ratio and types of silane coupling agents, curing method and ion-shower treatment were investigated. Dually curable coating method offered an optimally good quality film in both hardness and transmittance. The transparency and the hardness of the prepared films were increased with amounts of 3-(trimethoxysilyl)propylmethacrylate, and (3-glycidyloxypropyl)trimethoxysilane, respectively. The adhesion between coated layer and substrate could be enhanced by ion-shower treatment.

• Polymer(Korea)
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• v.37 no.6
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• pp.777-783
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• 2013

We used dipodal type bis[3-(trimethoxysilyl)propyl]amine (BTMA) silane coupling agent to modify silica nanoparticles to introduce secondary amino groups on the silica surface. These grafted N-H groups were reacted with glycidyl methacrylate (GMA) to introduce polymerizable methacrylate groups on the silica surface. After modification reaction, we used several analytical techniques such as Fourier transform infrared spectroscopy (FTIR), elemental analysis (EA) and solid state $^{13}C$ cross-polarization magic angle spinning (CP/MAS) nuclear magnetic resonance spectroscopy (NMR) to analyze the effects of reaction time, reaction temperature and used GMA concentration on the modification degree between N-H groups on the silica surface and epoxide groups of GMA. We found increased introduction of methacrylate groups on the silica surface by ring opening reaction of epoxide groups of GMA with N-H groups on BTMA treated silica with increased reaction time, reaction temperature and used GMA concentration within our experimental conditions.

• Bulletin of the Korean Chemical Society
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• v.25 no.7
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• pp.965-968
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• 2004

H-montmorillonite was modified by interlayer surface silylation using 3-aminopropyltriethoxysilane and dodecylamine in ethanol without a pre-swelling step. Dodecylamine acts as a gallery expander and silylation catalyst. The evaporation of ethanol from the dispersion yields well-ordered silylated montmorillonites with large basal spacing between 1.50 and 4.20 nm. Solid-state $^29Si$ CP MAS NMR of the silylated samples showed $Q^2\;and\;Q^3$ signals as well as $T^2\;and\;T^3$ signals. The increase in the relative intensity of $Q^3\;for\;Q^2$ and the appearance of $T^2\;and\;T^3$ signals was attributed to the grafting of 3-aminopropyltriethoxysilane to the interlayer surface silanol groups.

• Journal of the Korean Magnetic Resonance Society
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• v.6 no.1
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• pp.1-11
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• 2002

Physical properties of PVB [Poly(vinyl butyral)] polymer are strongly correlated with water contents in the polymer. Thus dynamics of PVB containing 10~50(w/w) ％ of water were studied by $^{13}$ C CP/MAS/DD over the temperature range 293K -348K. From the Peak area, line width, chemical shift, and relaxation times ( $T_{1}$ $T_{1p}$) measured at 9.4 T, it was deduced that water facilitates molecular dynamics of the PVB molecules overall including conformational exchange of the racemic and meso butyaldehyde rings in the PVB. However, the influence of water was not linear to the amount of water in the PVB samples. It is suggested that water up to 30 w/w ％ of the sample is closely bound to the PVB polymer and water relatively free from the PVB polymer starts to appear when water is added more than 30 w/w ％.％.

• Bulletin of the Korean Chemical Society
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• v.35 no.7
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• pp.2009-2012
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• 2014

An anionic surfactant, sodium dodecylbenzene sulfonate (SDBS), was introduced during the ultrasonication process for exfoliation of graphene. The surfactant plays the roles of exfoliator and stabilizer by binding to the graphene surface. The obtained modified graphene was characterized by Fourier-transform infrared spectroscopy (FT-IR) and solid state $^{13}C$ CP/MAS NMR to analyze the binding between molecules, and by X-ray diffraction (XRD) to characterize the bulk structure. The resulting graphene exhibited good dispersion stability in both water and organic solvents.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.24 no.1
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• pp.7-24
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• 1998

게 껍질로부터 얻은 키틴을 탈아세틸화하여 키토산을 얻었으며, 얻어진 키토산의 유기용매에 대한 용해성을 향상시키기 위해 알칼리 조건에서 고압반응ㅇ기를 사용하여 프로필렌옥사이드와 반응시켜 치환율 3.5의 히드록시프로필 키토산을 합성하였다. 합성된 히드록시프로필 키토산은 고체상 CP/MAS 13C-NMR, 1H-NMR, FT-IR을 통해 반응이 키토산의 6번 탄소의 수산기와 2번 탄소의 아민기에 주로 일어났음을 알 수 있었다. 또한 X-선 회절분석을 통해 키토산의 결정성이 프로필렌옥사이드와의 반응에 의해 크게 감소하였음을 알 수 있었고, 그 결과 유기 용매에 대한 용해성이 현저히 증가되는 현상을 나타내었다. 한편, 히드록시프로필 키토산을 수상에 녹인 후 W/O 에멀젼상에 서 알칼리 촉매를 사용항 에피클로로히드린과 가교반응을 실시한 결과 내부가 비어있는 중공 마이크로비드를 얻을 수 있었다. 전자현미경을 통한 분석결과 중공 마이크로비드의 껍질의 내부에는 스킨층이 형성되어 있었으며, 외부 표면은 다공성이 높은 비대칭 막으로 되어 있음을 확인할 수 있었다.

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1077-1079
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• 2009

To minimize the variance in the quantification of solid-state phases in powder samples, gently placing polycrystalline samples one next to another directly in a sample holder is better than trying to mix them homogeneously prior to transferring to a sample holder. However, the solid-state cross polarization-magic angle spinning (CP-MAS) nuclear magnetic resonance (NMR) spectroscopy results demonstrated that it is essential in this sampling method to place all the samples in the location of consistent signal sensitivity. The same sampling method may be employed in other spectroscopic quantification techniques of solid-state phases if the method to limit the sample to the location with uniform signal sensitivity in the sample holder is adapted to each technique.

• Journal of the Korean Magnetic Resonance Society
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• v.16 no.2
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• pp.103-110
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• 2012

Membrane proteins play a essential role in the biological systems and it is not easy to handle a membrane protein for its structural study. Solid-state NMR (ssNMR) can be a good tool to investigate the structures and dynamics of membrane proteins. In ssNMR, Magic Angle Spinning (MAS) and Cross Polarization (CP) can be utilized to reduce the line-broadening, leading to high resolution and sensitivity in the spectrum. ssNMR, if combined with other spectroscopic methods, can provide us a enough knowledge on structures and dynamics of membrane proteins in biological condition.

• Polymer(Korea)
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• v.36 no.6
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• pp.822-830
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• 2012

We used dipodal type bis[3-(trimethoxysilyl)propyl]amine (BTMA) silane coupling agent to modify silica nanoparticles to introduce secondary amino groups on the silica surface. These N-H groups were reacted with three different molecular weights (M.W. = 258, 575, and 700) of poly(ethylene glycol) diacrylates to introduce different attached layer thicknesses on the silica surface by Michael addition reaction. After Michael addition reaction, we used several analytical techniques such as fourier transform infrared spectroscopy (FTIR), elemental analysis (EA) and solid state $^{13}C$ cross-polarization magic angle spinning (CP/MAS) nuclear magnetic resonance spectroscopy to characterize introduced structures. We found almost complete Michael addition reaction of both two acrylate groups of PDGDA with N-H groups of BTMA modified silica to form ${\beta}$-amino acid esters. Between equimolar ratio of pure BTMA and pure PEGDA reaction, only one acrylate group of two acrylate groups of PEGDA reacted with N-H groups of pure BTMA to form ${\beta}$-amino acid ester and the other remaining acrylate group can be used to form a polymer later.