Conjugated microporous polymers for near-infrared photothermal control of shape change

Herein, a facile and highly efficient synthetic method to prepare organic photothermal materials with high photo-stability and outstanding photothermal performance is reported. Through direct polymerization of commercial aromatic monomers in the presence of anhydrous aluminium chloride and dichloromethane, four kinds of conjugated microporous polymers (CMPs) were obtained. Detailed structural analysis confirmed that the resultant CMPs possessed abundant micropores with an extended π-conjugated skeleton. Under near-infrared (NIR) light irradiation (808 nm, 1.0 W cm−2), all the CMPs showed fast heating-up behavior with their maximum temperatures higher than 150°C. Moreover, the efficiency of photothermal conversion (η) of the CMPs was found to increase linearly with the increase in the number of conjugated benzene rings within the monomer. Poly-TPE from tetraphenylethylene (TPE) and Poly-TP from o-terphenyl (TP) showed high η values of over 47%. Poly-TPE was additionally used as a photothermal filler to remotely and spatially control the shape recovery of thermal-sensitive shape memory polymers (SMPs), while its introduction (1 wt%) had little influence on the thermal and mechanical properties of the polymer matrixes. Owing to their excellent NIR photothermal performance as well as a one-step synthetic preparation, these CMPs may be promising photothermal materials for practical applications.