碳纳米管/聚己内酯复合材料，用于可持续能量收集

摘要：采用高性能可生物降解热电复合材料发电是一种可持续且极具前景的方法，可解决传统热电设备带来的环境问题。本文，新加坡国立大学Chaobin He等研究人员在《Small》期刊发表名为“High Thermoelectric Performance Carbon N

1成果简介

采用高性能可生物降解热电复合材料发电是一种可持续且极具前景的方法，可解决传统热电设备带来的环境问题。本文，新加坡国立大学Chaobin He等研究人员在《Small》期刊发表名为“High Thermoelectric Performance Carbon Nanotube/Polycaprolactone Composites for Sustainable Energy Harvesting”的论文，研究报道了一种基于单壁碳纳米管（SWCNT）的热电复合材料，采用可生物降解的聚己内酯（PCL）作为基体，显著提升了热电性能：当SWCNT质量分数达90%时，功率因子提升至439 µW m−1 K−2 。

PCL与SWCNT之间良好的表面相容性与界面相互作用，促进了大量PCL-SWCNT结的形成，从而实现高效能量滤波效应，使塞贝克系数在90%（质量分数）SWCNT含量时显著提升至40.8µV K−1。同时，薄PCL层对电荷隧穿的阻碍极小，从而保持了2635 S cm−1的高电导率。最终，由SWCNT/PCL复合薄膜组装的柔性热电装置在30.8K温差下展现出1.50W m−2 的功率密度，展现出在高性能、可持续热电能量收集领域巨大的应用潜力。

2图文导读

图1、a) Schematic illustration of the preparation process of the SWCNT/PCL composite film; b) Melt contact angle θ of PCL/SWCNT interface; c–h) SEM images of SWCNT/PCL composite films with different SWCNT loadings (10–90 wt.%) and neat SWCNT film; i) Molecular dynamics (MD) simulations of the interfacial behavior between PCL and SWCNT.

图2、a) ATR-FTIR spectra of SWCNT, PCL and SWCNT/PCL composite films, the absorption peaks ≈3000 to 2800 and 1850 to 1500 cm−1 were enlarged as b); c) Raman spectra of SWCNT, PCL and SWCNT/PCL composite films, the G-band ≈1592 cm−1 were enlarged in d); e) XRD spectra, and f) DSC curves of SWCNT, PCL and SWCNT/PCL composite films.

图3、Thermoelectric performance of SWCNT/PCL composite films as a function of SWCNT concentration. a) Electrical conductivity; b) Seebeck coefficient and c) power factors; d) Electrical conductivity, Seebeck coefficient, and e) power factor of SWCNT 90 wt.%/PCL composite films with different PCL molecular weight; f) Comparison of power factor and electrical conductivity between this work and biodegradable composites reported in literature.

图4、a) Temperature dependence of the normalized resistance of the SWCNT/PCL composite films; b) Analysis of R-T−1/2 relationship of the SWCNT/PCL composite films with the VRH model; c) Calculated energy barrier between localized states T0 of the SWCNT/PCL composite films; d) UV–vis spectra, e) UPS spectra and f) calculated work functions of pristine SWCNT, SWCNT 10 wt.%/PCL and SWCNT 90 wt.%/PCL composite films; g) Carrier properties (carrier mobility and concentration) of SWCNT/PCL composite films; h) Schematic illustration of the energy filtering effect in SWCNT/PCL composites.

图5、a) Photo of a flexible 5-leg TEG made from 90 wt.% SWCNT/10 wt.% PCL composites films on cellulose film substrate; b) Open-circuit voltage generated by the 5-leg TEG as a function of temperature; c) The output voltage–current curve of 5-leg TEG at different temperature gradients; d) The output power–current curve of 5-leg TEG at different temperature gradients; e) The output power of 5-leg TEG as a function of load resistance; f) Open-circuit voltage generated by human hands touching one end of the of 5-leg TEG; The resistance variation of the 5-leg TEG under different g) bending degrees and h) bending cycles.

3小结

综上所述，我们开发了一种基于单壁碳纳米管（SWCNTs）和可生物降解聚己内酯（PCL）的高性能环保型热电复合材料。研究证实，PCL与SWCNT之间良好的表面相容性及CH-π相互作用有利于形成PCL包裹SWCNT的结构。因此，当SWCNT浓度达90%时，塞贝克系数显著提升至40.8 µV K−1，这归因于复合材料内部形成的充分SWCNT-PCL接合点，可在低PCL负载下实现界面高效能量过滤。同时，该复合材料在PCL-SWCNT界面间仅存在有限的电荷隧穿阻碍，保持了2635 S cm⁻¹的高电导率。由此实现了439 µW m⁻¹ K⁻²的卓越功率因子，是纯SWCNT薄膜的3.7倍以上。此外，由单壁碳纳米管/聚乳酸薄膜与纤维素基板组装的柔性生物降解热电装置，在30.8 K温差条件下实现了127.8纳瓦的最大输出功率Pmax及1.50瓦每平方米的功率密度。本研究为开发适用于未来绿色电子应用的可持续高性能热电复合材料提供了前景广阔的途径。

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