Open Access Nano Express

Thermal diffusivity measurement of spherical gold nanofluids of different sizes/concentrations

Gerardo A López-Muñoz12*, José A Pescador-Rojas3, Jaime Ortega-Lopez4, Jaime Santoyo Salazar3 and J Abraham Balderas-López2

Author Affiliations

1 Química Aromática SA, Río Grande S/N, Col. Santa Catarina Acolman, México State, CP, 55875, Mexico

2 UPIBI-IPN, Av. Acueducto S/N, Col. Barrio la Laguna Ticomán, México City, CP, 07340, Mexico

3 Physics Department, CINVESTAV, Av. IPN 2508, Col. San Pedro Zacatenco, México City, CP, 07360, Mexico

4 Biotechnology Department, CINVESTAV, Av. IPN 2508, Col. San Pedro Zacatenco, México City, CP, 07360, Mexico

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Nanoscale Research Letters 2012, 7:423  doi:10.1186/1556-276X-7-423

Published: 30 July 2012

Abstract

In recent times, nanofluids have been studied by their thermal properties due to their variety of applications that range from photothermal therapy and radiofrequency hyperthermia (which have proven their potential use as coadjutants in these medical treatments for cancer diseases) to next-generation thermo-fluids. In this work, photoacoustic spectroscopy for a specific study of thermal diffusivity, as a function of particle size and concentration, on colloidal water-based gold nanofluids is reported. Gold nanoparticles were synthetized in the presence of hydroquinone through a seed-mediated growth with homogenous sizes and shapes in a range of 16 to 125 nm. The optical response, size and morphology of these nanoparticles were characterized using ultraviolet–visible spectroscopy and transmission electron microscopy, respectively. Thermal characterizations show a decrease in the thermal diffusivity ratio as the nanoparticle size is increased and an enhancement in thermal diffusivity ratio as nanoparticle concentration is added into the nanofluids. Compared with other techniques in the literature such as thermal lens and hot wire method, this photoacoustic technique shows an advantage in terms of precision, and with a small amount of sample required (500 μl), this technique might be suitable for the thermal diffusivity measurement of nanofluids. It is also a promising alternative to classical techniques.

Keywords:
Gold nanoparticles; Nanofluids; Photoacoustic; Thermal diffusivity