Combinatory effects of nanocarbon- and radiation-induced networks on free-volume heterogeneity, nonisothermal crystallization, and electrorecovery

Abstract

Electro shape-memory polymers (eSMPs) are highly regarded for their ability to undergo preordained transformations in response to electrical cues, a feature intrinsically linked to the prevailing electrical conduction pathways and macromolecular configurations. Alterations through the introduction of nanoparticles or the implementation of crosslinking techniques can produce synergistic or antagonistic shifts in the free volume and nonisothermal crystallization behavior. To date, such effects have remained largely unexplored. In this study, we developed gamma radiation-processed eSMPs that exhibit superior electrorecovery capabilities (approximately 100% recovery at 7.5 V) intrinsically connected to the specific radiation dose administered. Furthermore, we examined the changes in the free volume, extensional viscosity, rheology, and nonisothermal crystallization of these electroconductive composites. Our findings highlight the necessity of a critical radiation dose for the induction of electroshape recovery, and evidence suggests that the radiation dose substantially reduces the crystallization temperature under nonisothermal conditions while simultaneously broadening the crystallization process, especially at high cooling rates. Analyses of extensional stress further underscored the critical role of radiation dose. Positron annihilation lifetime spectroscopy (PALS) studies revealed that both the NCB and radiation dose contribute to an overall reduction in the free-volume size.