Nanodiamond Nanofluids for Enhanced Thermal Conductivity

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• 作者：Blake T. Branson ; Paul S. Beauchamp ; Jeremiah C. Beam ; Charles M. Lukehart ; Jim L. Davidson
• 刊名：ACS Nano
• 出版年：2013
• 出版时间：April 23, 2013
• 年：2013
• 卷：7
• 期：4
• 页码：3183-3189
• 全文大小：391K
• 年卷期：v.7,no.4(April 23, 2013)
• ISSN：1936-086X

文摘

Deaggregation of oxidized ultradispersed diamond (UDD) in dimethylsulfoxide followed by reaction with glycidol monomer, purification via aqueous dialysis, and dispersion in ethylene glycol (EG) base fluid affords nanodiamond (ND)鈥損oly(glycidol) polymer brush:EG nanofluids exhibiting 12% thermal conductivity enhancement at a ND loading of 0.9 vol %. Deaggregation of UDD in the presence of oleic acid/octane followed by dispersion in light mineral oil and evaporative removal of octane gives ND路oleic acid:mineral oil dispersions exhibiting 11% thermal conductivity enhancement at a ND loading of 1.9 vol %. Average particle sizes of ND additives, determined by dynamic light scattering, are, respectively, ca. 11 nm (in H₂O) and 18 nm (in toluene). Observed thermal conductivity enhancements outperform enhancement effects calculated using Maxwell鈥檚 effective medium approximation by 2- to 4-fold. Covalent ND surface modification gives 2-fold greater thermal conductivity enhancement than ND surface modification via hydrogen-bonding interactions at similar concentrations. Stable, static ND:mineral oil dispersions are reported for the first time.

Keywords:

nanodiamond; nanofluid; thermal conductivity; surface functionalization; surfactant