Zhang Mao, Cao Xiaoyin, Wen Ming, Chen Chuanliang, Wen Qichao, Fu Qiang, Deng Hua
College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University, Chengdu 610065, P. R. China.
Special Polymer Materials for Automobile Key Laboratory of Sichuan Province, Sichuan Chuanhuan Technology Co. Ltd., Dazhou 635100, P. R. China.
ACS Appl Mater Interfaces. 2023 Mar 1;15(8):10947-10957. doi: 10.1021/acsami.2c21025. Epub 2023 Feb 16.
Materials based on poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) can be potentially employed as flexible thermoelectric generators (TEGs) to capture waste heat and generate electrical energy. Among various methods, secondary doping is an effective way to modulate its thermoelectric (TE) performance. Different from conventional measures such as dropping, soaking, and steam fumigation, strong shear is integrated with the doping process and termed high-velocity non-solvent turbulent secondary doping (HNTD). We systematically investigate the transformation of PEDOT:PSS during this procedure and the formation mechanism of its highly conductive pathway. It is illustrated that PEDOT:PSS experiences PSS swelling, the phase separation of PEDOT from PSS, the removal of isolated PSS, and the evolution of PEDOT to a linear conformation. These evolutions contribute to the substantial elevation of electrical conductivity (σ). Furthermore, by employing continuous single-walled carbon nanotube (SWCNT) networks as structural units, highly conductive flexible PEDOT:PSS/SWCNT TE thin films could be prepared without sacrificing the Seebeck coefficient (). Additionally, the effect of HNTD and direct addition method on TE properties of composite films is also compared. Finally, the PEDOT:PSS composite film with 40 wt % SWCNTs by the HNTD method exhibits the maximized power factor (PF) of 501.31 ± 19.23 μW m K with σ of 4717.8 ± 41.51 S cm and of 32.6 ± 0.13 μV K at room temperature. It is worth mentioning that the σ value 4717.8 ± 41.51 S cm is the highest among the composites based on commercial carbon fillers and organic semiconductors. Finally, a 6-leg TEGs prototype is assembled and illustrates an output power of 4.416 μW under a temperature difference (Δ) of 58 K. It is thought that such a strategy may provide some guidelines for manufacturing PEDOT:PSS-based functional materials.
基于聚（3,4 - 乙撑二氧噻吩）：聚（苯乙烯磺酸盐）（PEDOT:PSS）的材料有潜力用作柔性热电发电机（TEG）来捕获废热并产生电能。在各种方法中，二次掺杂是调节其热电（TE）性能的有效途径。与诸如滴涂、浸泡和蒸汽熏蒸等传统方法不同，强剪切与掺杂过程相结合，并被称为高速非溶剂湍流二次掺杂（HNTD）。我们系统地研究了此过程中PEDOT:PSS的转变及其高导电通路的形成机制。结果表明，PEDOT:PSS经历了PSS溶胀、PEDOT与PSS的相分离、孤立PSS的去除以及PEDOT向线性构象的演变。这些演变导致电导率（σ）大幅提高。此外，通过使用连续的单壁碳纳米管（SWCNT）网络作为结构单元，可以制备出高导电的柔性PEDOT:PSS/SWCNT TE薄膜，而不会牺牲塞贝克系数（）。此外，还比较了HNTD和直接添加法对复合薄膜TE性能的影响。最后，通过HNTD方法制备的含40 wt%SWCNT的PEDOT:PSS复合薄膜在室温下表现出最大的功率因子（PF）为501.31±19.23 μW m⁻¹ K⁻²，σ为4717.8±41.51 S cm⁻¹，为32.6±0.13 μV K⁻¹。值得一提的是，4717.8±41.51 S cm⁻¹的σ值在基于商业碳填料和有机半导体的复合材料中是最高的。最后，组装了一个六腿TEG原型，在58 K的温差（Δ）下展示了4.416 μW的输出功率。人们认为这种策略可能为制造基于PEDOT:PSS的功能材料提供一些指导。
