Yongqiang Guo, Shuangshuang Wang, Haitian Zhang, Hua Guo, Mukun He, Kunpeng Ruan, Ze Yu, Guang-sheng Wang*, Hua Qiu and Junwei Gu*. Consistent Thermal Conductivities of Spring-like Structured Polydimethylsiloxane Composites under Large Deformation. Advanced Materials, 2024, 36: 2404648. 2023IF=27.4
https://doi.org/10.1002/adma.202404648
Abstract
Flexible and highly thermally conductive materials with consistent thermal conductivity (λ) during large deformation are urgently required to address the heat accumulation in flexible electronics. In this study, spring-like thermal conduction pathways of silver nanowire (S-AgNW) fabricated by 3D printing are compounded with polydimethylsiloxane (PDMS) to prepare S-AgNW/PDMS composites with excellent and consistent λ during deformation. The S-AgNW/PDMS composites exhibit a λ of 7.63 W m?1 K?1 at an AgNW amount of 20 vol%, which is ≈42 times that of PDMS (0.18 W m?1 K?1) and higher than that of AgNW/PDMS composites with the same amount and random dispersion of AgNW (R-AgNW/PDMS) (5.37 W m?1 K?1). Variations in the λ of 20 vol% S-AgNW/PDMS composites are less than 2% under a deformation of 200% elongation, 50% compression, or 180° bending, which benefits from the large deformation characteristics of S-AgNW. The heat-transfer coefficient (0.29 W cm?2 K?1) of 20 vol% S-AgNW/PDMS composites is ≈1.3 times that of the 20 vol% R-AgNW/PDMS composites, which reduces the temperature of a full-stressed central processing unit by 6.8 °C compared to that using the 20 vol% R-AgNW/PDMS composites as a thermally conductive material in the central processing unit.柔性電子領域的熱量積聚問題使其對大形變下導熱穩定的柔性高導熱材料需求迫切。本文采用3D打印技術制備具有大形變能力的銀納米線螺旋導熱通路（S-AgNW），將其與聚二甲基硅氧烷（PDMS）復合制備大形變下具有優異和穩定導熱性能的S-AgNW/PDMS復合材料。AgNW體積分數為20 vol%的S-AgNW/PDMS復合材料的導熱系數（λ）達7.63 W m-1 K-1，約為純PDMS的λ（0.18 W m-1K-1）的42倍，也遠高于相同體積分數AgNW在PDMS基體中隨機分散的R-AgNW/PDMS復合材料的λ（5.37 W m-1 K-1）。得益于AgNW螺旋導熱通路的大形變特性，20 vol% S-AgNW/PDMS導熱復合材料在200%伸長率、50%壓縮率和180°彎曲角度等形變下的λ變化率均小于2%。此外，20 vol% S-AgNW/PDMS導熱復合材料的傳熱系數（0.29 W cm-2 K-1）約為20 vol% R-AgNW/PDMS導熱復合材料傳熱系數（0.22 W cm-2 K-1）的1.3倍，用于CPU散熱時可使其滿功率工作溫度較20 vol% R-AgNW/PDMS復合材料作為散熱材料時的CPU溫度降低6.8oC。
論文亮點
1. 采用3D打印技術制備具有大形變能力的銀納米線（AgNW）螺旋導熱通路，將其與PDMS復合制備大形變下具有優異和穩定導熱性能的S-AgNW/PDMS復合材料。
2. AgNW體積分數為20 vol%的S-AgNW/PDMS復合材料的λ達7.63 W m-1 K-1，約為純PDMS的λ（0.18 W m-1 K-1）的42倍，其在200%伸長率、50%壓縮率和180°彎曲角度等形變下的λ變化率均小于2%。
3. 掃描電子顯微鏡和微納尺度熱傳導模擬表明，AgNW螺旋導熱通路的大形變特性使AgNW在S-AgNW/PDMS導熱復合材料形變時發生的位移變化很小，不影響整體的熱傳導過程。
作者：郭永強郵件地址：gyqnpu@nwpu.edu.cn
點擊查看更多詳情