• Environmental Engineering Research
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• 제21권1호
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• pp.99-107
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• 2016

The adsorption of inorganic mercury, Hg (II), in aqueous solution has been investigated to evaluate the effectiveness of synthesized gold (Au) nanoparticle-coated silica as sorbent in comparison with activated carbon and Au-coated sand. The synthesis of the Au-coated silica was confirmed by x-ray diffraction (Bragg reflections at $38.2^{\circ}$, $44.4^{\circ}$, $64.6^{\circ}$, and $77.5^{\circ}$) and the Au loading on silica surface was $6.91{\pm}1.14mg/g$. The synthesized Au-coated silica performed an average Hg adsorption efficiency of ~96 (${\pm}2.61$) % with KD value of 9.96 (${\pm}0.32$) L/g. The adsorption kinetics of Hg(II) on to Au-coated silica closely follows a pseudo-second order reaction where it is found out to have an initial adsorption rate of $4.73g/{\mu}g/min/$ and overall rate constant of $4.73{\times}10^{-4}g/{\mu}g/min/$. Au-coated silica particles are effective in removing Hg (II) in aqueous solutions due to their relatively high KD values, rapid adsorption rate, and high overall efficiency that can even decrease mercury levels below the recommended concentrations in drinking water.

• Advances in nano research
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• 제14권2호
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• pp.117-126
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• 2023

This experimental study investigated friction stir welding (FSW) of the acrylonitrile-butadiene-styrene (ABS) T-joint in the presence of various nano-silica levels. This study aim to handle the drawbacks of the friction stir welding (FSW) of an ABS T-joint with various quantity of nanoparticles and assess the performance of nanoparticles in the welded joint. Moreover, the relationship between the nanoparticle quantity and FSW was analyzed using response surface methodology (RSM) Box-Behnken design. The input parameters were the tool rotation speed (400, 600, 800 rpm), the transverse speed (20, 30, 40 mm/min), and the nano-silica level (0.8, 1.6, 2.4 g). The tensile strength of the prepared specimens was determined by the universal testing machine. Silica nanoparticles were used to improve the mechanical properties (the tensile strength) of ABS and investigate the effect of various FSW parameters on the ABS T-joint. The results of Box-Behnken RSM revealed that sound joints with desired characteristics and efficiency are fabricated at tool rotation speed 755 rpm, transverse speed 20 mm/min, and nano-silica level 2.4 g. The scanning electron microscope (SEM) images revealed the crucial role of silica nanoparticles in reinforcing the ABS T-joint. The SEM images also indicated a decrease in the nanoparticle size by the tool rotation, leading to the filling and improvement of seams formed during FSW of the ABS T-joint.

• Bulletin of the Korean Chemical Society
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• 제26권12호
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• pp.1927-1928
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• 2005

• 한국세라믹학회지
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• 제45권10호
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• pp.605-609
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• 2008

This work describes the preparation of functionalized magnetic nanoparticles(MNPs) and their bioapplication to human DNA separation. Silica coated MNPs were prepared by changing the volume ratio of tetraethyl orthosilicate(TEOS) for controlled coating thickness on the original nanoparticle of MNPs. The sol-gel process in silica coating on MNPs surface was adapted for relatively mild reaction condition, low-cost, and surfactant-free. And then amino functionalized magnetic nanoparticles were synthesized using amine groups as surface modifiers. The result of adsorption efficiency for human DNA with amino-functionalized silica coated MNPs was calculated as a function of the number of amine groups.

• Bulletin of the Korean Chemical Society
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• 제34권2호
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• pp.539-544
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• 2013

$Ag@SiO_2@SiO_2$(FITC) nanocomposites were prepared by the simple polyol process and St$\ddot{o}$ber method. Fluorescence enhancement of fluorescein moiety (fluorescein isothiocyanate, FITC) was investigated in the presence of silver nanoparticles in $Ag@SiO_2@SiO_2$(FITC) system with varying thickness (X nm) of first silica shell. Maximum enhancement factor of 4.3 fold was achieved in $Ag@SiO_2@SiO_2$(FITC) structure with the first silica shell thickness of 8 nm and the average separation distance of 11 nm between the surface of silver nanoparticle and fluorescein moiety. The enhancement is believed to be originated from increased excitation rate of fluorescein moiety due to concentrated local electromagnetic field which was improved by interaction of light with silver nanoparticles.

• 분석과학
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• 제23권6호
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• pp.579-586
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• 2010

현재 상업적으로 널리 사용 되여 지고 있는 항암제인 hydroxy urea, 6-mercaptopurine monohydrate, cytosine arabinoside, cyclophosphamide monohydrate 그리고 uracil를 3-(triethoxysilyl) propyl isocyanate 와 반응시켜 항암제가 붙어있는 3-(triethoxysilyl)propyl amide (compound I)을 합성한후 물과 가수분해 반응시켜 항암제가 결합된 silica 나노입자(10 nm~micronparticles)를 만들 수있었다. Silyl isocyanate 유도체들은 물과 반응하여 유기물질-silica 나노입자가 포함된 $-CH_2-CH_2-CH_2-NH-COOH$ 그룹이나 혹은 온도와 용매등 반응조건에 따라서 decarboxylated 된 propylamine 그룹이 생성되었다. 생체외 시험에서 항암제가 결합된 silica 나노입자는 종양 세포 제거에 효과적이고 정상세포에 거의 영향을 미치지 않는 것으로 나타났다. 그리고 악성 종양인 폐, 난소, 악성 흑색종, 중추신경계(CNS)와 결장 종양 세포가 이 연구에 사용되었다. 현재의 연구에서 전달매체 로서 silica는 silation 반응으로 손쉽게 나노입자를 얻을 수 있으므로 본 연구에 쉽게 이용 할 수 있다. 결과로부터 이 기술은 보다 부작용이 적은 생체 의약품에 적합한 carrier nanoparticles에 적용 될 수 있을 것으로 판단된다.

• Bulletin of the Korean Chemical Society
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• 제33권3호
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• pp.1067-1070
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• 2012

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2003년도 춘계총회 및 연구발표회 초록집
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• pp.159.1-159
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• 2003

• 분석과학
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• 제20권5호
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• pp.413-418
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• 2007

방사선 방법에 의해 실리카 나노입자에 CdS 나노입자를 코팅하였다. TEM분석결과, $SiO_2$ 나노입자 표면에 CdS의 입자의 크기는 대략 20 nm임을 확인 하였다. 또한, XRD 분석결과 결정체 화합물임을 확인하였다. PL 분석결과 PVP-CdS 나노입자와 $SiO_2$@CdS 복합체의 경우, 방출특성이 상당히 다르다는 것이 확인되었다. PVP-CdS의 경우, 방출스펙트럼이 550 nm-600 nm 에서 나타나고, $SiO_2$@CdS의 방출스펙트럼의 경우 단파장 이동함을 확인하였다. 또한 새로운 피이크 (450 nm) 나타남을 확인하였는데, 이는 CdS 의 유발양자 제한 효과에 의한 것으로 사료된다.

• 한국분말재료학회지
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• 제25권5호
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• pp.420-425
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• 2018

Core-shell structured nanoparticles are garnering attention because these nanoparticles are expected to have a wide range of applications. The objective of the present study is to improve the coating efficiency of gold shell formed on the surface of silica nanoparticles for $SiO_2@Au$ core-shell structure. For the efficient coating of gold shell, we attempt an in-situ synthesis method such that the nuclei of the gold nanoparticles are generated and grown on the surface of silica nanoparticles. This method can effectively form a gold shell as compared to the conventional method of attaching gold nanoparticles to silica particles. It is considered possible to form a dense gold shell because the problems caused by electrostatic repulsion between the gold nanoparticles in the conventional method are eliminated.