氟橡膠/碳填材/離子液體複合材料用於柔性熱電發電機

Abstract

本研究使用氟橡膠作為基底，並添加單壁奈米碳管(SWCNT)、碳黑(CB)和離子液體(IL)來製備熱電複合材料。SWCNT具有優異的導電性，但在F-rubber基質中容易聚集。實驗結果表明，CB有效填充了SWCNT之間的間隙，形成導電網絡，增強了導電性。一種特殊的離子液體，1-ethyl-3-methylimidazolium trifluoromethanesulfonate [EMIM][TfO]，被發現可以作為F-rubber的塑化劑，提供更好的拉伸性能，並有效地作為SWCNT的摻雜劑。附著在交聯氟橡膠基材上的F-rubber/SWCNT/CB/[EMIM][TfO]複合材料可以在50%的應變下重複拉伸，而不會導致性能顯著下降。此外，將氟橡膠、奈米銀線（AgNW）和另一種離子液體1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [EMIM][Tf2N]混合，製備了電導率超過10000 S/cm的高導電彈性體。使用F-rubber/AgNW/[EMIM][Tf2N]彈性體作為導線將六片熱電複合材料串聯在交聯氟橡膠基板上，形成全氟橡膠基底的柔性熱電發電機。在18 K的溫差下，它產生86 μW cm-2的功率密度，並且在彎曲半徑為5 mm的1,000次彎曲循環後仍保持原始功率密度的88%。這項研究開發了低成本、低毒性的柔性熱電材料，有潛力為穿戴式微型設備發電。

In this work, fluorine rubber (F-rubber) was used as the matrix and single-walled carbon nanotube (SWCNT), carbon black (CB), and ionic liquids were incorporated to prepare thermoelectric composites. SWCNT has excellent electrical conductivity but tends to aggregate in F-rubber matrix. The experimental results show that CB effectively fills the gaps between SWCNT, forming a conductive network and enhancing conductivity. A specific ionic liquid, 1-ethyl-3-methylimidazolium trifluoromethanesulfonate [EMIM][TfO], has been found to act as a plasticizer for F-rubber, providing better tensile properties, and effectively serving as a dopant for SWCNT. The F-rubber/SWCNT/CB/[EMIM][TfO] composite attached to the cross-linked F-rubber substrate can be repeatedly stretched at a strain of 50% without causing a significant deterioration of performance. Furthermore, a high conductive elastomer of a conductivity above 10000 S/cm was prepared by mixing F-rubber, silver nanowire (AgNW), and another ionic liquid, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [EMIM][Tf2N]. Six pieces of the thermoelectric composites were connected in series on the cross-linked F-rubber substrate using the F-rubber/AgNW/[EMIM][Tf2N] elastomer as the conductive wires to create a full F-rubber-based flexible thermoelectric generator. Under a temperature difference of 18 K, it produces a power density of 86 μW cm-2 and maintains 88% of its original power density after 1,000 bending cycles with a bending radius of 5 mm. This study develops low-cost, low-toxicity flexible thermoelectric materials, potentially generating power for wearable microdevices.