title: Enhancing the Thermal Conductance of Polymer and Sapphire Interface via Self-Assembled Monolayer.
abstract: Interfacial thermal conductance (ITC) receives enormous consideration because of its significance in determining thermal performance of hybrid materials, such as polymer based nanocomposites. In this study, the ITC between sapphire and polystyrene (PS) was systematically investigated by time domain thermoreflectance (TDTR) method. Silane based self-assembled monolayers (SAMs) with varying end groups, -NH2, -Cl, -SH and -H, were introduced into sapphire/PS interface, and their effects on ITC were investigated. The ITC was found to be enhanced up by a factor of 7 through functionalizing the sapphire surface with SAM, which ends with a chloride group (-Cl). The results show that the enhancement of the thermal transport across the SAM-functionalized interface comes from both strong covalent bonding between sapphire and silane-based SAM, and the high compatibility between the SAM and PS. Among the SAMs studied in this work, we found that the ITC almost linearly depends on solubility parameters, which could be the dominant factor influencing on the ITC compared with wettability and adhesion. The SAMs serve as an intermediate layer that bridges the sapphire and PS. Such a feature can be applied to ceramic-polymer immiscible interfaces by functionalizing the ceramic surface with molecules that are miscible with the polymer materials. This research provides guidance on the design of critical-heat transfer materials such as composites and nanofluids for thermal management.
authors: Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, PR China.
authors: Kun
authors: K
authors: Zheng
authors: Institute of Engineering Thermophysics, Chinese Academy of Sciences , Beijing 100190, PR China.
authors: Fangyuan
authors: F
authors: Sun
authors: Institute of Engineering Thermophysics, Chinese Academy of Sciences , Beijing 100190, PR China.|Department of Mechanical Engineering, University of Minnesota , Minneapolis, Minnesota 55455, United States.
authors: Jie
authors: J
authors: Zhu
authors: Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, PR China.
authors: Yongmei
authors: Y
authors: Ma
authors: School of Energy and Power Engineering, Huazhong University of Science and Technology , Wuhan 430074, PR China.
authors: Xiaobo
authors: X
authors: Li
authors: Institute of Engineering Thermophysics, Chinese Academy of Sciences , Beijing 100190, PR China.
authors: Dawei
authors: D
authors: Tang
authors: Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, PR China.
authors: Fosong
authors: F
authors: Wang
authors: Department of Mechanical Engineering, University of Minnesota , Minneapolis, Minnesota 55455, United States.
authors: Xiaojia
authors: X
authors: Wang
keywords: interfacial thermal conductance; miscibility; organic−inorganic interface; solubility parameter; time domain thermoreflectance