Guruge Amali G, Makki Hesam, Troisi Alessandro
Department of Chemistry, University of Liverpool Liverpool L69 3BX UK
J Mater Chem C Mater. 2024 Oct 18;12(47):19245-19257. doi: 10.1039/d4tc03066d. eCollection 2024 Dec 5.
In various bioelectronic applications, conductive polymers come into contact with biological tissues, where water is the major component. In this study, we investigated the interface between the conductive polymer poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) and water, focusing on how the morphology of the PEDOT:PSS is altered by water permeation. We constructed well-equilibrated PEDOT:PSS-water systems in both PEDOT- and PSS-rich phases. Our findings show that water permeates into the polymer through a complex network of water channels, which exhibit a similar pore size distribution in both PEDOT- and PSS-rich phases, leading to similar water intake in these phases. Compared to the dry state of the polymer, water permeation leads to the formation of smaller, less ordered, and distantly located lamella crystallites, potentially resulting in reduced conductivity. Therefore, we argue that these structural changes from the dry state of the polymer to the wet state may be the origin of the significant conductivity reduction observed experimentally in PEDOT:PSS in water or PEDOT:PSS hydrogels.
在各种生物电子应用中，导电聚合物会与生物组织接触，而水是生物组织的主要成分。在本研究中，我们研究了导电聚合物聚（3,4 - 亚乙基二氧噻吩）：聚苯乙烯磺酸盐（PEDOT:PSS）与水之间的界面，重点关注水渗透如何改变PEDOT:PSS的形态。我们在富含PEDOT和富含PSS的相中构建了平衡良好的PEDOT:PSS - 水体系。我们的研究结果表明，水通过复杂的水通道网络渗透到聚合物中，这些水通道在富含PEDOT和富含PSS的相中呈现出相似的孔径分布，导致这两个相中吸水量相似。与聚合物的干燥状态相比，水的渗透导致形成更小、排列更无序且间距更远的片晶微晶，这可能导致电导率降低。因此，我们认为从聚合物的干燥状态到湿润状态的这些结构变化可能是在水中的PEDOT:PSS或PEDOT:PSS水凝胶中实验观察到的显著电导率降低的原因。
