Thermal conduction in polymeric nanofluids under mean field approximation: role of interfacial adsorption layers

Autor:	M R Nisha, J Philip
Rok vydání:	2013
Předmět:	Hydrodynamic radius Materials science Nanoparticle chemistry.chemical_element Condensed Matter Physics Thermal conduction Copper Atomic and Molecular Physics and Optics Adsorption Thermal conductivity Nanofluid chemistry Particle Composite material Mathematical Physics
Zdroj:	Physica Scripta. 88:015602
ISSN:	1402-4896 0031-8949
DOI:	10.1088/0031-8949/88/01/015602
Popis:	Polymeric nanofluids of TiO2/PVA (polyvinyl alcohol) and Cu/PVA have been prepared by dispersing nanoparticles of TiO2 or metallic copper in PVA. The thermal diffusivities and thermal conductivities of these nanofluids have been measured as a function of particle loading following a thermal wave interference technique in a thermal wave resonant cavity. It is found that in both cases thermal conductivity increases with particle concentration, with Cu/PVA nanofluids showing a much larger increase. The results have been compared with the corresponding values calculated following different theoretical models. Comparison of the results with model-based calculations shows that the thermal conductivity variations in these nanofluids are within the framework of the classical mean field theory including the formation of thin interfacial adsorption layers around nanoparticles. Although the molecular weight of PVA is very high, it is found that the adsorption layer thickness is limited by the hydrodynamic radius of the nanoparticles. It is found that particle clustering followed by interfacial layering accounts for the larger increase in thermal conductivity found for Cu/PVA compared to TiO2/PVA.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::b2f7e6284edc5d58ae7295a2431dfd8a https://doi.org/10.1088/0031-8949/88/01/015602 Zobrazit plný text záznamu