Role of Nanoparticle Clustering on the Effective Thermal Conductivity of Concentrated Silica Colloids

Published

January 13, 2010

Author(s)

Tae Joon Cho, Michael R. Zachariah, Chunwei Wu, Jiajun Xu, Donggeun Lee, Bao Yang

Abstract

Recent research on nanofluids has offered particle clustering as a possible mechanism for the enhancement of the effective thermal conductivity (k) when nanoparticles are dispersed in liquids. This article is focused on an experimental and theoretical assessment of this effect, by altering the cluster structure, size distribution, and thermal conductivity of solid particles in water. Starting with well-dispersed SiO2 sols in water as a reference system, we control the aggregation kinetics by adjusting pH. Contrary to previous model predictions, the present experiment showed that clustering did not show any discernable enhancement in the thermal conductivity even at high volume loading. A series of fractal model calculations suggests that the conductive benefit due to clustering might be completely compensated by the reduced convective contribution due to particle growth.

Citation

Physical Review E (Statistical, Nonlinear, and Soft Matter Physics)

Volume

81

Issue

1

Pub Type

Journals

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DOI Link

Citation

Cho, T. , Zachariah, M. , Wu, C. , Xu, J. , Lee, D. and Yang, B. (2010), Role of Nanoparticle Clustering on the Effective Thermal Conductivity of Concentrated Silica Colloids, Physical Review E (Statistical, Nonlinear, and Soft Matter Physics), [online], https://doi.org/10.1103/PhysRevE.81.011406 (Accessed January 2, 2025)