Nanodiamond Nanofluids for Enhanced Thermal Conductivity
Nanodiamond Nanofluids for Enhanced Thermal Conductivity
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DOI：
10.1021/nn305664x
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发表时间：
2013-04-01
期刊：
影响因子：
17.1
通讯作者：
Davidson, Jim L.
中科院分区：
文献类型：
--
作者：
Branson, Blake T.;Beauchamp, Paul S.;Davidson, Jim L.
氧化的超分散金刚石（UDD）在二甲基亚砜中解聚，然后与缩水甘油单体反应，通过水透析纯化，并分散在乙二醇（EG）基液中，得到纳米金刚石（ND）-聚（缩水甘油）聚合物刷：EG纳米流体在ND负载为0.9体积%时表现出12%的热导率增强。UDD在油酸/辛烷存在下解聚，然后分散在轻质矿物油中并蒸发除去辛烷，得到ND。油酸：矿物油分散体在1.9体积%的ND负载下表现出11%的热导率增强。通过动态光散射测定的ND添加剂的平均粒度分别为约100 nm和约100 nm。11 nm（在H2O中）和18 nm（在甲苯中）。所观察到的热导率增强优于使用麦克斯韦的有效介质近似计算的增强效果2至4倍。共价ND表面改性比ND表面改性在相似浓度下通过氢键相互作用提供2倍更大的热导率增强。首次报道了稳定的静态ND：矿物油分散体。
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)-poly(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. 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's 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.