Nature Communications (Jul 2024)

Reversible two-way tuning of thermal conductivity in an end-linked star-shaped thermoset

  • Chase M. Hartquist,
  • Buxuan Li,
  • James H. Zhang,
  • Zhaohan Yu,
  • Guangxin Lv,
  • Jungwoo Shin,
  • Svetlana V. Boriskina,
  • Gang Chen,
  • Xuanhe Zhao,
  • Shaoting Lin

DOI
https://doi.org/10.1038/s41467-024-49354-2
Journal volume & issue
Vol. 15, no. 1
pp. 1 – 12

Abstract

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Abstract Polymeric thermal switches that can reversibly tune and significantly enhance their thermal conductivities are desirable for diverse applications in electronics, aerospace, automotives, and medicine; however, they are rarely achieved. Here, we report a polymer-based thermal switch consisting of an end-linked star-shaped thermoset with two independent thermal conductivity tuning mechanisms—strain and temperature modulation—that rapidly, reversibly, and cyclically modulate thermal conductivity. The end-linked star-shaped thermoset exhibits a strain-modulated thermal conductivity enhancement up to 11.5 at a fixed temperature of 60 °C (increasing from 0.15 to 2.1 W m−1 K−1). Additionally, it demonstrates a temperature-modulated thermal conductivity tuning ratio up to 2.3 at a fixed stretch of 2.5 (increasing from 0.17 to 0.39 W m−1 K−1). When combined, these two effects collectively enable the end-linked star-shaped thermoset to achieve a thermal conductivity tuning ratio up to 14.2. Moreover, the end-linked star-shaped thermoset demonstrates reversible tuning for over 1000 cycles. The reversible two-way tuning of thermal conductivity is attributed to the synergy of aligned amorphous chains, oriented crystalline domains, and increased crystallinity by elastically deforming the end-linked star-shaped thermoset.