Synthesis of Gold Nanoparticles Stabilized by 3-(Aminopropyl)Triethoxysilane through (N, N-Dimethylformamide) Reduction

2012 ◽  
Vol 184-185 ◽  
pp. 1298-1301
Author(s):  
Yan Ming Chen ◽  
Jing Wang

gold nanoparticles were synthesized in DMF (N, N-dimethylformamide) solution by using 3-(aminopropyl)triethoxysilane as stabilizer through wet chemical route. A characteristic surface plasmon band can be observed for the obtained gold nanoparticles from UV-vis absorption spectra, which indicate that KH-550 can serve as stabilizing agent for the formation of gold nanoparticles. The influence of reaction temperature, reaction time and precursor concentrations on the formation of gold nanoparticles is investigated through UV-vis absorption spectra. The results show that surface plasmon absorption peak could be red-shifted when reaction temperature, reaction time and precursor concentrations increase. Transmission electron microscopy (TEM) results show that the obtained gold nanoparticles with spherical morphology have a narrow size distribution.

2008 ◽  
Vol 8 (9) ◽  
pp. 4415-4423 ◽  
Author(s):  
Lanlan Sun ◽  
Yonghai Song ◽  
Li Wang ◽  
Yujing Sun ◽  
Cunlan Guo ◽  
...  

The interaction between HAuCl4 and DNA has enabled creation of DNA-templated gold nanoparticles without formation of large nanoparticles. It was found that spheral DNA-HAuCl4 hybrid of 8.7nm in diameter, flower-like DNA-HAuCl4 hybrid, nanoparticles chains and nanoparticles network of DNA-HAuCl4 hybrid could be obtained by varying the reaction conditions, including DNA concentration and reaction temperature. The intermediate product was investigated by shortening the reaction time of DNA and HAuCl4, and the obtained nanoparticles preserved a small DNA segment, which indicated that the reaction between DNA and HAuCl4 had a process. The addition of reduction reagent resulted in DNA-templated gold nanoparticles and nanoflowers, respectively. UV-vis absorption spectra were used to characterize the DNA-HAuCl4 hybrid and the gold nanostructures templated on DNA, and XPS spectra were used to compare the composition of DNA-Au(III) complex and gold nanoparticles. AFM and TEM results revealed that the spheral gold nanoparticles of about 11 nm in size and flower-like gold nanoparticles were formed after the addition of NaBH4.


2007 ◽  
Vol 7 (12) ◽  
pp. 4333-4338
Author(s):  
Gulay Ertas ◽  
Sefik Suzer

Optical properties of plasmon coupled silver and gold nanoparticles were studied as a function of the refractive index of the surrounding medium. Our studies confirmed that the effect of changes in the refractive index of the surrounding medium was more difficult to demonstrate from an experimental point of view, because of the very high susceptibility of nanoparticles to aggregate in aqueous and organic solvents. Whereas the position of the absorption bands of triiodide in these solvents shows a clear dependence on medium's refractive index, the surface plasmon band position of silver and gold nanoparticles do not exhibit the same dependence. This is attributed to a non-negligible interaction of these solvents with nanoparticle surfaces.


2011 ◽  
Vol 239-242 ◽  
pp. 1118-1122 ◽  
Author(s):  
Ping Ke Yan ◽  
Bin Wang ◽  
Yu Juan Gao

In this paper, nesquehonite whiskers were synthesized by low-temperature aqueous solution method, and the impacts of reaction temperature, reaction time and surfactant dosage and other factors on the maximum whisker length and high aspect ratios of nesquehonite whiskers were also investigated. Results showed that under the conditions that the reaction temperature was 40 – 50 °C the reaction time was 50 – 60min and the amount of surfactant dosage was 1% (by mass), high aspect ratios nesquehonite whisker products can be synthesized. On this basis, growth mechanism of the nesquehonite whiskers was discussed.


1998 ◽  
Vol 536 ◽  
Author(s):  
A. L. Rogach ◽  
A Eychmüller ◽  
J. Rockenberger ◽  
A. Kornowski ◽  
H. Weller ◽  
...  

AbstractCdSe and CdTe nanoclusters were formed in aqueous solutions at moderate temperatures by a wet chemical route in the presence of thiols as effective stabilizing agents. The nature of the stabilizing agent (thioalcohols or thioacids) had an important influence on the particle size and largely determined the photoluminescence properties. The nanoclusters were characterized by means of UV-vis absorption and photoluminescence spectroscopy, powder X-ray diffraction, high resolution transmission electron microscopy, and extended X-ray absorption fine structure measurements. CdSe and CdTe nanoclusters were crystalline, in the cubic zincblende phase, with mean sizes in the range of 2 to 5 nm depending on the preparative conditions and the postpreparative size-selective fractionation, and showed pronounced electronic transitions in the absorption spectra. Thioglycerol-stabilized CdTe nanoclusters possessed sharp band-egde photoluminescence being tunable with particle size.


Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1087
Author(s):  
Caroline R. Basso ◽  
Taís F. Cruz ◽  
Bruna L. Silva ◽  
Valber A. Pedrosa ◽  
João P. Araújo Junior

The aim of the current study is to introduce a methodology aimed at producing a biosensor that uses gold nanoparticles (AuNPs) to detect porcine circovirus 2 (PCV-2). This biosensor was based on AuNPs, which were modified with self-assembled monolayers (SAMs) and antibodies. The AuNPs’ surface and virus modification process applied to enable antibody binding was accompanied by localized surface plasmon resonance (LSPR), surface plasmon resonance (SPR), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). Virus quantification was possible by the light absorption difference in the spectrum at concentrations of 105, 106, 107, 108, and 109 DNA copies/mL PCV-2 in relation to quantitative PCR (qPCR), with an R2 value >0.98. The visualization of colorimetric changes in the different PCV-2 concentrations was possible without the use of equipment. The biosensor production methodology presented reproducibility and specificity, as well as easy synthesis and low cost. An enhanced version of it may be used in the future to replace traditional tests such as PCR.


2013 ◽  
Vol 22 ◽  
pp. 654-659 ◽  
Author(s):  
LUTFUL KABIR ◽  
SWAPAN K. MANDAL

We report here the structural and optical properties of Bi nanoparticles in polymer (polypyrrole) matrix. The nanoparticles are synthesized following a wet chemical route. The X-ray diffraction data clearly shows the growth of single crystalline Bi nanoparticles within the host polymer. The microstructure of the Bi nanoparticles obtained by transmission electron microscopy (TEM) reveals clearly the formation of spherical shaped nanoparticles of average size∼27 nm with a narrow size distribution. The optical absorption spectrum exhibits a distinct peak at 278 nm which is attributed to the surface plasmon band of Bi nanoparticles. The absorption spectrum is found to be described well following Mie theory.


2017 ◽  
Vol 45 ◽  
pp. 34-41 ◽  
Author(s):  
Qin Shi ◽  
Jing Xu ◽  
Li Feng Dang ◽  
Jun Chen ◽  
Guo Gang Tang ◽  
...  

TiSe2 nanobelts/nanoplates have been successfully fabricated through a facile and environment-friendly pressureless sintered process using micro-sized Ti and Se elements as raw materials. The morphology and structure of the as-prepared TiSe2 products were investigated by X-ray diffractometer, scanning electron microscopy, transmission electron microscopy and high resolution transmission electron microscopy. The experimental results indicated that the morphology of TiSe2 products were strongly dependent on the reaction temperature and reaction time. As the reaction temperature was set at 600°C and 800°C, long belts-like and plates-like structures of as-prepared TiSe2 products could be observed, respectively. However, a mixture of nanobelts and nanoplates could be obtained at a reaction temperature of 700°C. It was also found that the reaction time played a crucial role in obtaining the homogeneous distribution nanoparticles, therefore, reasonable reaction process and formation mechanisms of as-prepared TiSe2 nanoparticles were proposed. Moreover, the tribological properties of the TiSe2 nanobelts/nanoplates were investigated. The test results showed that the addition of TiSe2 nanoparticles could improve the tribological properties of base oil. Furthermore, the friction coefficient of base oil containing TiSe2 nanoplates was lower and more stable than those of TiSe2 nanobelts and pure base oil.


2014 ◽  
Vol 672-674 ◽  
pp. 172-176
Author(s):  
Min Zhang ◽  
Jin Yang Li ◽  
Hai Bin Fu

To study the saccharification conditions of cellulase on lignocellulose material, this paper used corn straw as the material to do research on the effect of cellulase. The hydrolysis factors, including reaction temperature, reaction time and cellulase concentration, were measured in order to determine the optimal saccharification conditions for fuel ethanol production. The results showed that, when the reaction temperature was 45°C, reaction time was 72 h and cellulase concentration was 60 IU/g, the hydrolysis rate can respectively reach 6.25 %, 14.7 % and 14.4 %. By the analysis of orthogonal test, the main factors effects the saccharification was reaction time. And the optimal combination of saccharification conditions was the reaction time of 54 h, the reaction temperature of 45 °C, and the cellulase concentration of 55 IU/g.


Micromachines ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 274 ◽  
Author(s):  
Tingting Hong ◽  
Aijuan Lu ◽  
Wenfang Liu ◽  
Chuanpin Chen

A method was developed to synthesize silver nanoparticles with controlled size and Localized Surface Plasmon Resonance (LSPR) wavelength. In a microchip, droplets with high monodispersity and stability were produced. Using droplets as microreactors, seed-mediated growth approach was successfully applied for silver nanoparticles preparation. It was observed that nanoparticles size and LSPR wavelength could be optimized via adjusting synthesis conditions, such as droplets heating temperature, reaction time, and concentration of silver seeds and silver nitrate in aqueous phase. These results indicated that the proposed microdevices could provide a convenient and inexpensive approach for preparing nanoparticles with optimum properties.


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