Photothermal Stimuli-Responsive Biocomposites Based on Cross-Linked Poly(l-malic acid) Reinforced with Carbon Nanotubes

Carbon nanotubes (CNTs) have high photothermal conversion efficiency and hence can be used to prepare light-absorbing nanocomposites with polymers. In this study, an interesting type of nanocomposites based on the biomass-derived poly( l -malic acid) (PLMA) filled with CNTs were developed. CNTs were grafted with PLMA oligomers and then participated in the cross-linking of the PLMA. The as-obtained biocomposites show highly improved mechanical strengths and good biocompatibility with decreased rates of degradation. The elastoplastic response was then used as a probe to detect relations between the dispersion of CNTs and the relaxations of cross-linking networks. As a green and light-absorbing material, the cross-linked PLMA/CNT nanocomposite possesses good photoabsorption efficiency and photothermal conversion stability. The shape-memory behavior of the cross-linked PLMA matrix is activated then, and the recovery process can be controlled step by step. Using this kind of biocomposites, intelligent devices with programmable photothermal responses and tunable material performance can be easily fabricated.