Fan Qiao, Zhang Kai, Wei Lanlan, Gong Yongji, Qin Shuhao, He Min, Liu Yufei, Luo Tingting, Peng Shigui, Yu Jie
Department of Polymer Material and Engineering, College of Materials and Metallurgy, Guizhou University, Guiyang 550025, China.
National Engineering Research Center for Compounding and Modification of Polymeric Materials, Guiyang 550014, China.
ACS Appl Mater Interfaces. 2025 Jul 23;17(29):42278-42292. doi: 10.1021/acsami.5c08001. Epub 2025 Jul 14.
Flexible wearable devices have significant potential for diverse applications, prioritizing the development of portable, safe, and stable dry electrodes. This study focused on designing six poly(sodium styrenesulfonate) (PSS) variants with controlled molecular weights (10k-70k), combined with a water-soluble soft polymer, poly(vinyl alcohol) (PVA), to enhance the electrical properties, mechanical strength, and long-term stability of the Poly(3,4-ethylenedioxythiophene) (PEDOT): PSS polymer complex. We systematically examined morphological modifications, interactions, and conductive processes of PVA/PEDOT: PSS films, along with the mechanisms behind their improved stretchability and resistance stability. Results indicate that low molecular weight PSS provides the best mechanical flexibility due to stronger hydrogen bonding with PVA, enhancing elongation at break. However, insulating domains in PSS and PVA impede carrier transport, leading to a discontinuous charge hopping process along the PEDOT backbone, which decreases electrical conductivity. Conversely, high molecular weight PSS exhibits poor dispersion of rigid segments and conductive materials, resulting in decreased electrical and mechanical properties. Notably, with a molecular weight of 34k, the PVA/PEDOT: PSS film exhibits excellent electrical performance and mechanical flexibility, maintains good resistance stability after 1000 loading and unloading cycles at 30% strain, and demonstrates clear and stable electromyography (EMG) signals, indicating vast potential for EMG electrodes.
柔性可穿戴设备在多种应用中具有巨大潜力，因此便携式、安全且稳定的干电极的开发成为优先事项。本研究聚焦于设计六种具有可控分子量（10k - 70k）的聚（苯乙烯磺酸钠）（PSS）变体，并与水溶性软聚合物聚乙烯醇（PVA）相结合，以增强聚（3,4 - 乙撑二氧噻吩）（PEDOT）：PSS聚合物复合物的电学性能、机械强度和长期稳定性。我们系统地研究了PVA/PEDOT：PSS薄膜的形态变化、相互作用和导电过程，以及其拉伸性和电阻稳定性提高背后的机制。结果表明，低分子量的PSS由于与PVA形成更强的氢键，提供了最佳的机械柔韧性，提高了断裂伸长率。然而，PSS和PVA中的绝缘区域阻碍了载流子传输，导致沿PEDOT主链的电荷跳跃过程不连续，从而降低了电导率。相反，高分子量的PSS表现出刚性链段和导电材料的分散性较差，导致电学和机械性能下降。值得注意的是，分子量为34k的PVA/PEDOT：PSS薄膜表现出优异的电学性能和机械柔韧性，在30%应变下经过1000次加载和卸载循环后仍保持良好的电阻稳定性，并显示出清晰稳定的肌电图（EMG）信号，表明其在EMG电极方面具有巨大潜力。
