A new article out of a collaboration between Dr. Ning Yan and Dr. Jing Chen’s labs has been published in the ACS Sustainable Chemistry & Engineering written by Xiaozhen Ma, Xiaolin Wang, Honglong Zhao, Minghui Cui, Xiaobo Xu, Fangfang Kong, Peng Chen, Ning Yan, Jin Zhu and Jing Chen.

You can find the article here

Abstract

In this study, we successfully synthesized lignin-based covalent adaptable polyurethane networks containing lignin-graphite nanosheet composite particles with a light controllable positive temperature coefficient (LPTC) effect. The use of lignin facilitated the direct exfoliation of graphite, thus overcoming the challenge of achieving a uniform dispersion of conductive fillers in the polymer matrix. The exfoliated graphite had a thickness of approximately 3.0 nm, which was equivalent to three to five layers of graphene. By preparing lignin-based covalent adaptable polyurethane without graphite composite particles (LPU) and lignin-based covalent adaptable polyurethane with graphite composite particles (LPU-G), we achieved remoldable properties and a high LPTC intensity for LPU-G. LPU-60G (60 represents the mass fraction of lignin-graphite nanosheets in polyols) exhibited an excellent LPTC effect, with sharp increases in resistance under light, particularly under near-infrared light (NIR), enabling the control of the current in circuits. Additionally, both LPU and LPU-G demonstrated degradability by slowly degrading in a PBS solution while rapidly degrading in an alkaline solution. Overall, the LPU-G synthesized in this study displayed superior stability in the LPTC effect and possessed degradability, providing a promising avenue for the future development of smart materials.