Molecular Structure Effect of a Self-Assembled Monolayer on Thermal Resistance across an Interface

Autor: Lijian Song, Youchen Zhang, Weimin Yang, Jing Tan, Lisheng Cheng
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Polymers, Vol 13, Iss 21, p 3732 (2021)
Druh dokumentu: article
ISSN: 2073-4360
DOI: 10.3390/polym13213732
Popis: Understanding heat transfer across an interface is essential to a variety of applications, including thermal energy storage systems. Recent studies have shown that introducing a self-assembled monolayer (SAM) can decrease thermal resistance between solid and fluid. However, the effects of the molecular structure of SAM on interfacial thermal resistance (ITR) are still unclear. Using the gold–SAM/PEG system as a model, we performed nonequilibrium molecular dynamics simulations to calculate the ITR between the PEG and gold. We found that increasing the SAM angle value from 100° to 150° could decrease ITR from 140.85 × 10−9 to 113.79 × 10−9 m2 K/W owing to penetration of PEG into SAM chains, which promoted thermal transport across the interface. Moreover, a strong dependence of ITR on bond strength was also observed. When the SAM bond strength increased from 2 to 640 kcal⋅mol−1Å−2, ITR first decreased from 106.88 × 10−9 to 102.69 × 10−9 m2 K/W and then increased to 123.02 × 10−9 m2 K/W until reaching a steady state. The minimum ITR was obtained when the bond strength of SAM was close to that of PEG melt. The matching vibrational spectra facilitated the thermal transport between SAM chains and PEG. This work provides helpful information regarding the optimized design of SAM to enhance interfacial thermal transport.
Databáze: Directory of Open Access Journals
Nepřihlášeným uživatelům se plný text nezobrazuje