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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.


The colors of gold nanoplate suspensions fabricated by CR with sonication time of 0, 10, 20, 30, 45, and 60 min (left to right).
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Figure 5: The colors of gold nanoplate suspensions fabricated by CR with sonication time of 0, 10, 20, 30, 45, and 60 min (left to right).

Mentions: The particle size and shape change significantly with the aid of ultrasonication (Group D samples), as shown by SEM images in Figure 4. In general, the particle becomes smaller, more regular, with more products exhibiting hexagonal shapes with the increase of ultrasonication time. Depending on the ultrasonication duration, the resultant dispersions display different colors, Figure 5. The average particle size measured by DLS method is shown in Figure 6. The particle-size reduction levels off at an approximate ultrasonication time of 45 min. Such a result demonstrates that ultrasonic irradiation is a very useful tool to engineer different particle morphologies. It can be strong enough to prompt reaction even just within 10 min, resulting in over 50% reduction in the average particle size, Figure 6. Compared with spherical particles, the application of ultrasonication to homogenize the synthesis process is more effective for gold nanoplates.


Ultrasonic-aided fabrication of gold nanofluids.

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

The colors of gold nanoplate suspensions fabricated by CR with sonication time of 0, 10, 20, 30, 45, and 60 min (left to right).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 5: The colors of gold nanoplate suspensions fabricated by CR with sonication time of 0, 10, 20, 30, 45, and 60 min (left to right).
Mentions: The particle size and shape change significantly with the aid of ultrasonication (Group D samples), as shown by SEM images in Figure 4. In general, the particle becomes smaller, more regular, with more products exhibiting hexagonal shapes with the increase of ultrasonication time. Depending on the ultrasonication duration, the resultant dispersions display different colors, Figure 5. The average particle size measured by DLS method is shown in Figure 6. The particle-size reduction levels off at an approximate ultrasonication time of 45 min. Such a result demonstrates that ultrasonic irradiation is a very useful tool to engineer different particle morphologies. It can be strong enough to prompt reaction even just within 10 min, resulting in over 50% reduction in the average particle size, Figure 6. Compared with spherical particles, the application of ultrasonication to homogenize the synthesis process is more effective for gold nanoplates.

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.