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Ultrasonic-aided fabrication of gold nanofluids.

Chen HJ, Wen D - Nanoscale Res Lett (2011)

Bottom Line: The ultrasonication technique is found to be a very powerful tool in engineering the size and shape of GNPs.Subsequent property measurement shows that both particle size and particle shape play significant roles in determining the effective thermal conductivity.A large increase in effective thermal conductivity can be achieved (approximately 65%) for gold nanofluids using plate-shaped particles under low particle concentrations (i.e.764 μM/L).

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Engineering and Materials Science, Queen Mary University of London, London, UK. d.wen@qmul.ac.uk.

ABSTRACT
A novel ultrasonic-aided one-step method for the fabrication of gold nanofluids is proposed in this study. Both spherical- and plate-shaped gold nanoparticles (GNPs) in the size range of 10-300 nm are synthesized. Subsequent purification produces well-controlled nanofluids with known solid and liquid contents. The morphology and properties of the nanoparticle and nanofluids are characterized by transmission electron microscopy, scanning electron microscope, energy dispersive X-ray spectroscope, X-ray diffraction spectroscopy, and dynamic light scattering, as well as effective thermal conductivities. The ultrasonication technique is found to be a very powerful tool in engineering the size and shape of GNPs. Subsequent property measurement shows that both particle size and particle shape play significant roles in determining the effective thermal conductivity. A large increase in effective thermal conductivity can be achieved (approximately 65%) for gold nanofluids using plate-shaped particles under low particle concentrations (i.e.764 μM/L).

No MeSH data available.


TEM image of the control sample (sodium citrate concentration 0.5%, inset: resulting dispersion of red-wire color).
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Figure 1: TEM image of the control sample (sodium citrate concentration 0.5%, inset: resulting dispersion of red-wire color).

Mentions: The resulting dispersion from CR method exhibits a clear wine-red color (Group A samples). TEM images of these nanoparticles are shown in Figure 1. The average size of the GNPs is approximately in the range of 15-20 nm in diameter, and the shape is spherical. The particle size distribution in the liquid phase is measured by the DLS method. A narrow size-distribution is found, typically in the range of 10-30 nm, as shown in Figure 2. It should be noted that the measured particle size in the liquid medium is generally larger than the primary particle size even under fully dispersed status (no agglomeration), as the DLS measures the hydrodynamic size of the particles, determined by the Brownian motion effect. Consequently the DLS result reveals almost a fully dispersed particle status in the liquid. Further control of the pore size of the membrane filter allows for a narrower size distribution.


Ultrasonic-aided fabrication of gold nanofluids.

Chen HJ, Wen D - Nanoscale Res Lett (2011)

TEM image of the control sample (sodium citrate concentration 0.5%, inset: resulting dispersion of red-wire color).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211254&req=5

Figure 1: TEM image of the control sample (sodium citrate concentration 0.5%, inset: resulting dispersion of red-wire color).
Mentions: The resulting dispersion from CR method exhibits a clear wine-red color (Group A samples). TEM images of these nanoparticles are shown in Figure 1. The average size of the GNPs is approximately in the range of 15-20 nm in diameter, and the shape is spherical. The particle size distribution in the liquid phase is measured by the DLS method. A narrow size-distribution is found, typically in the range of 10-30 nm, as shown in Figure 2. It should be noted that the measured particle size in the liquid medium is generally larger than the primary particle size even under fully dispersed status (no agglomeration), as the DLS measures the hydrodynamic size of the particles, determined by the Brownian motion effect. Consequently the DLS result reveals almost a fully dispersed particle status in the liquid. Further control of the pore size of the membrane filter allows for a narrower size distribution.

Bottom Line: The ultrasonication technique is found to be a very powerful tool in engineering the size and shape of GNPs.Subsequent property measurement shows that both particle size and particle shape play significant roles in determining the effective thermal conductivity.A large increase in effective thermal conductivity can be achieved (approximately 65%) for gold nanofluids using plate-shaped particles under low particle concentrations (i.e.764 μM/L).

View Article: PubMed Central - HTML - PubMed

Affiliation: School of Engineering and Materials Science, Queen Mary University of London, London, UK. d.wen@qmul.ac.uk.

ABSTRACT
A novel ultrasonic-aided one-step method for the fabrication of gold nanofluids is proposed in this study. Both spherical- and plate-shaped gold nanoparticles (GNPs) in the size range of 10-300 nm are synthesized. Subsequent purification produces well-controlled nanofluids with known solid and liquid contents. The morphology and properties of the nanoparticle and nanofluids are characterized by transmission electron microscopy, scanning electron microscope, energy dispersive X-ray spectroscope, X-ray diffraction spectroscopy, and dynamic light scattering, as well as effective thermal conductivities. The ultrasonication technique is found to be a very powerful tool in engineering the size and shape of GNPs. Subsequent property measurement shows that both particle size and particle shape play significant roles in determining the effective thermal conductivity. A large increase in effective thermal conductivity can be achieved (approximately 65%) for gold nanofluids using plate-shaped particles under low particle concentrations (i.e.764 μM/L).

No MeSH data available.