Exploring the Effects and Interactions of Conducting Polymers in the Volume Phase Transition of Thermosensitive Conducting Hydrogels

Abstract

Conducting polymers (CPs) play a vital role in imparting electrochemical and photothermal properties to thermosensitive conducting hydrogels (TCH). The application of TCH is expanding not only for biomedical applications but also to address water scarcity. While the volume phase transition (VPT) phenomenon in thermosensitive polymers has been extensively studied, the contribution of CPs to this process and the underlying chemical interactions remain unclear and low explored. In this study, we present a novel conducting polymer hydrogel (CPH) utilizing the thermosensitive polymer poly(Nisopropylacrylamide) (PNIPAAm) enriched with poly(3,4-ethylenedioxythiophene) (PEDOT) nanoparticles as a model system. This serves as a platform for both experimental and theoretical investigations into the influence of CPs on VPT. Through a comprehensive examination of hydrogel responses to temperature employing Raman spectroscopy, atomistic simulations using advanced hybrid methodologies, and artificial intelligence, we unveil a shielding effect of CP. This effect arises from robust chemical interactions with NIPAAm, inducing a selective dehydration of the hydrogel microenvironment. Remarkably, this mirrors the phenomenon observed during VPT triggered by an increase in the hydrogel temperature. Understanding the intricate interactions between conducting and thermosensitive polymers is imperative for the systematic development and fine-tuning of the performance of future CPHs. This knowledge ensures a more precise adaptation of these materials to their intended end applications.