In Situ Alloying of Thermally Conductive Polymer Composites by Combining Liquid and Solid Metal Microadditives
In Situ Alloying of Thermally Conductive Polymer Composites by Combining Liquid and Solid Metal Microadditives
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DOI：
10.1021/acsami.7b15814
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发表时间：
2018-01-17
影响因子：
9.5
通讯作者：
Rykaczewski, Konrad
中科院分区：
文献类型：
--
作者：
Ralphs, Matthew I.;Kemme, Nicholas;Rykaczewski, Konrad
室温液态金属（LM）是热界面材料（TIM）的有吸引力的候选者，因为它们具有适度高的导热性和液体性质，这使得它们能够以很小的热阻很好地贴合配合表面。然而，由于许多金属微电子元件的镓驱动退化，镓基LM可能会引起关注。我们提出了一种三组分复合材料与LM，铜（Cu）微粒，和聚合物基体，作为一种更便宜，无腐蚀性的解决方案。固体铜颗粒与LM中的镓原位且在室温下形成合金，从而固定LM并消除附近部件的任何腐蚀问题。三组分复合材料的结构-性能-工艺关系的研究表明，添加剂共混的方法和程度显著地改变了所得的热传递性能。特别地，LM和Cu添加剂的任何组合的微分散导致大量界面和低于2 W m（-1）K-1的热导率。相比之下，预混LM和Cu颗粒胶体到聚合物基质中的较短共混程序产生具有多分散填料和高达17 W m（-1）K-1的有效固有热导率（高达10 W m（-1）K-1的有效热导率）的复合物。LM-Cu胶体合金化到CuGa 2中提供了有限但实用的时间框架，以在复合材料硬化并固化成具有永久特性之前将未固化的复合材料铸造成期望的形状、空间或空隙。
Room-temperature liquid metals (LMs) are attractive candidates for thermal interface materials (TIMs) because of their moderately high thermal conductivity and liquid nature, which allow them to conform well to mating surfaces with little thermal resistance. However, gallium-based LMs may be of concern due to the gallium-driven degradation of many metal microelectronic components. We present a three-component composite with LM, copper (Cu) micro particles, and a polymer matrix, as a cheaper, noncorrosive solution. The solid copper particles alloy with the gallium in the LM, in situ and at room temperature, immobilizing the LM and eliminating any corrosion issues of nearby components. Investigation of the structure-property-process relationship of the three-component composites reveals that the method and degree of additive blending dramatically alter the resulting thermal transport; roperties. In particular, micro dispersion of any combination of the LM and Cu additives results in a large number of interfaces and a thermal conductivity below 2 W m(-1) K-1. In contrast, a shorter blending procedure of premixed LM and Cu particle colloid into the polymer matrix yields a composite with polydispersed filler and effective intrinsic thermal conductivities of up to 17 W m(-1) K-1 (effective thermal conductivity of up to 10 W m(-1) K-1). The LM-Cu colloid alloying into CuGa2 provides a limited, but practical, time frame to cast the uncured composite into the desired shape, space, or void before the composite stiffens and cures with permanent characteristics.