• Bulletin of the Korean Chemical Society
• /
• 제35권9호
• /
• pp.2621-2624
• /
• 2014

The rapid and spontaneous adsorption of proteins on nanoparticle (NP) surfaces in biological fluids such as blood is an important phenomenon as it possibly determines "what the cells see" and, thus, the fates of NPs in living organisms. In order to quantitatively understand protein coronas at the molecular level, we investigated human serum albumin (HSA) coronas that were produced on silica NPs of 20 nm and 50 nm diameters using conventional gel electrophoresis. Analysis of the concentration dependence of protein adsorption showed that HSA coronas preferentially formed a monolayer on silica NPs and revealed the presence of hard protein coronas. HSA adsorption was clearly dependent on NP size, and this might be due to the different surface curvatures of NPs of different sizes.

• 한국환경과학회지
• /
• 제17권7호
• /
• pp.711-717
• /
• 2008

The use of support materials on the nanoparticle synthesis and applications has advantages in many aspects; resisting the aggregation and gelation of nanoparticles, providing more active sites by dispersing over the supports, and facilitating a filtering process. In order to elucidate the influence of the supports on the nitrate reduction reactivity, the supported iron nanoparticles were prepared by borohydride reduction of an aqueous iron salt in the presence of supports such as activated carbon, silica and polyethylene. The reactivity for nitrate reduction decreased in the order of unsupported Fe(0) > activated carbon(AC) supported Fe(0) > polyethylene(PE) supported Fe(0) ${\ge}$ silica supported Fe(0). Rate constants decrease with increasing initial nitrate concentration implying that the reaction is limited by the surface reaction kinetics.

• 한국막학회:학술대회논문집
• /
• 한국막학회 2003년도 The 4th Korea-Italy Workshop
• /
• pp.129-132
• /
• 2003

Silica/SUS composite membranes were prepared for CO removal from products of methanol steam reforming. A support was prepared by coating Ni powder of sub-micron and SiO$_2$ sols of particle size of 500nm and 150nm in turns on a porous stainless steel (SUS) substrate. Silica top layer was coated on the modified support using colloidal sol with nanoparticle. As a result of mixture gas permeation test of silica composite membrane using H$_2$(99%)/CO(1%), CO concentration of 10000 ppm was reduced to under 81 ppm, which is acceptable in PEMFC anode gas specification. Permeation mechanism through the membrane was mainly molecular sieving.

• Advances in concrete construction
• /
• 제7권1호
• /
• pp.51-63
• /
• 2019

The project focuses on the dynamic analysis of concrete beams reinforced with silica-nanoparticles under blast loading. The structure is located at two boundary conditions. The equivalent composite properties are determined using Mori-Tanak model. The structure is simulated with sinusoidal shear deformation theory. Employing nonlinear strains-displacements, stress-strain, the energy equations of beam were obtained and using Hamilton's principal, the governing equations were derived. Using differential quadrature methods (DQM) and Newmark method, the dynamic deflection of the structure is obtained. The influences of volume percent and agglomeration of silica nanoparticles, geometrical parameters of beam, boundary condition and blast load on the dynamic deflection were investigated. Results showed that with increasing volume percent of silica nanoparticles, the dynamic deflection decreases.

• 접착 및 계면
• /
• 제23권3호
• /
• pp.70-74
• /
• 2022

탄닌산은 식물 유래 폴리페놀 중 하나로, 대부분의 생체고분자와 분자간결합을 할 수 있어서 분자적 접착제로서 연구가 되어 왔으며, 표면 개질, 에너지 저장 및 발생 장치, 의료용 제재로서 활용이 되고 있다. 본 연구에서는 약물 전달과 바이오이미징 등 의생명공학 분야에서 다양하게 활용되는 다공성 실리카 나노입자를 합성하고, 탄닌산을 이용하여 다공성 실리카 나노입자의 표면을 개질 한 뒤, 나노입자의 표면을 분석하였다.

• Journal of Ceramic Processing Research
• /
• 제13권spc1호
• /
• pp.78-81
• /
• 2012

Colloidal titania nanoparticles were synthesized by a simple sol-gel process. The obtained nanoparticles showed high crystallinity and were of the anatase type. These crystalline colloidal titania nanoparticles were organically modified using methyl- and glycidyl-grafted silanes in order to enhance their stability and solution processability. The stabilized colloidal titania nanoparticles could be dispersed homogeneously without aggregation and converted into silica-titania hybrid films with the heterogeneous Si-O-Ti bonds by a low-temperature solution process. The fabricated silica-titania hybrid films showed high transparency (~ 90%) in the visible range, and low RMS roughness (<1 nm). Therefore, the organosilane-modified crystalline colloidal titania nanoparticles can be used in solution-processable functional coatings for electro-optical devices.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
• /
• pp.257-257
• /
• 2013

In order to selectively remove oil and organic compound from water, silica nanoparticles with hydrophobic coating was used. Since silica nanoparticles are generally hydrophilic, removal efficiency of oil and organic compound, such as toluene, in water can be decreased due to competitive adsorption with water. In order to increase the removal efficiency of oil and toluene, hydrophobic polydimethylsiloxane (PDMS) was coated on silica nanoparticles in the form of thin film. Hydrophobic property of the PDMS-coated silica nanoparticles and hydrophilic silica nanoparticles were easily confirmed by putting it in the water, hydrophilic particle sinks but hydrophobic particle floats. PDMS coated silica nanoparticles were dispersed on a slide glass with epoxy glue on and the water contact angle on the surface was determined to be over $150^{\circ}$, which is called superhydrophobic. FT-IR spectroscopy was used to check the functional group on silica nanoparticle surface before and after PDMS coating. Then, PDMS coated silica nanoparticles were used to selectively remove oil and toluene from water, respectively. It was demonstrated that PDMS coated nanoaprticles selectively aggregates with oil and toluene in the water and floats in the form of gel and this gel remained floating over 7 days. Furthermore, column filled with hydrophobic PDMS coated silica nanoparticles and hydrophilic porous silica was prepared and tested for simultaneous removal of water-soluble and organic pollutant from water. PDMS coated silica nanoparticles have strong resistibility for water and has affinity for oil and organic compound removal. Therefore PDMS-coated silica nanoparticles can be applied in separating oil or organic solvents from water.

• 공업화학
• /
• 제21권1호
• /
• pp.34-39
• /
• 2010

${\gamma}-Methacryloxypropyl$이 가진 기능성 그룹으로 silica nanoparticle의 유기변형은 silica의 표면개질로 성공적으로 준비했다. 또한 ethanol 용매에서 AAm을 사용하는 radical 침전중합을 통해서 polyacrylamide를 MPSN nanosphere에 'raft from'방법으로 microsphere가 성공적으로 graft중합되었다. FTIR과 XPS는 ultra-fine silica particle의 표면에서 실리카개질이 공유결합하는 것을 보여주며 SEM분석은 ultra-fine particle과 유기변형된 입자는 각각 25, 30, 35 nm의 크기로 응집작용을 효과적으로 막아주고 나누어줌을 증명할 수 있다는 것을 보여준다.

• Macromolecular Research
• /
• 제16권7호
• /
• pp.626-630
• /
• 2008

Poly(vinyl pyrrolidone) was used successfully to control the size and distribution of silver nanoparticles generated on inorganic silica nanofibers. The inorganic nanofibers were electro spun using sol-gel chemistry of silicates, and the diameter of the prepared nanofibers was unaffected by adding up to 7% of poly(vinyl pyrrolidone). The silver ions, in the form of silver nitrate, were introduced into the silica nanofibers and reduced to metallic silver by ultraviolet irradiation with a subsequent thermal treatment. The size of the generated silver particles was decreased dramatically by adding poly(vinyl pyrrolidone). The size of the silver nanoparticles was 73 nm when no poly(vinyl pyrrolidone) was added but 23 nm with the addition of only 1% of poly(vinyl pyrrolidone). The extent of reduction could be checked by determining the concentration of silver ions leached into water from the silica nanofibers. After thermal treatment of the silica nanofibers, more than 99% of the silver remained in the nanofibers, indicating almost complete reduction of the silver ions to silver metal.

• Korean Chemical Engineering Research
• /
• 제49권2호
• /
• pp.181-186
• /
• 2011

본 연구에서는 실리카 나노 입자의 표면 개질을 위해 실란 커플링제인 3-(trimethoxysilyl)propylmethacrylate(MPS) 를 사용하여 표면 개질 반응을 수행하였다. 용매의 pH, MPS의 가수 분해 반응시간, 표면 개질 반응시간 및 실리카 표면의 실라놀기(Si-OH)에 대한 MPS의 몰 비를 변화하여 각각의 반응조건이 실리카 표면개질 반응에 미치는 영향을 연구하였다. 개질반응 후 Fourier Transform Infrared Spectroscopy(FTIR), 원소분석(EA) 및 고체 상태 cross-polarization magic angle spinning(CP/MAS) Nuclear Magnetic Resonance Spectroscopy(NMR)법을 사용하여 표면이 개질된 실리카 입자들의 분석을 수행하였다. 연구 결과 용매의 pH가 4.5일 때 MPS가 단량체 형태로 실리카 표면의 실라놀기와 반응하고 이외의 pH에서는 MPS가 이량체, 삼량체 혹은 사량체의 올리고머 형태로 실리카의 실라놀기와 반응함이 우세함을 나타내었다. 가수분해반응 시간을 30분에서 90분으로 증가시키면 MPS가 올리고머 형태로 실리카 표면의 실라놀기와 반응하는 것이 우세하고, 투입한 MPS 몰 비의 증가도 MPS가 올리고머 형태로 실리카 표면의 실라놀기와 반응하는 것이 우세함을 나타내었다.