Tuning of sunlight-induced self-cleaning and self-healing attributes of an elastomeric nanocomposite by judicious compositional variation of the TiO2–reduced graphene oxide nanohybrid

Abstract

Achieving combined attributes of shape memory, self-healing and self-cleaning properties within a material is a daunting challenge to materials scientists. Here, a hyperbranched polyurethane (HPU)–TiO₂/reduced graphene oxide (TiO₂/RGO) nanocomposite was fabricated to address the afore-stated challenge. The fabricated nanocomposite exhibited composition and dose-dependent mechanical properties with excellent shape recovery ratio (91–95%) as well as shape recovery rate (1–3 min) under exposure to sunlight. Most importantly, the nanocomposite demonstrated both repeatable intrinsic self-healing (within 7.5–10 min) and efficient self-cleaning ability by removing model dirt, methylene blue, (within 2–3 h) under the same energy exposure. The study also showed that these novel properties of the nanocomposite can be tuned by judicious choice of the amount and composition of the nanohybrid. The presence of a high amount of RGO (0.5–1 weight%) in the nanocomposite helps in rapid and efficient healing, whereas a high amount of TiO₂ nanoparticles (5–10 weight%) aids in achieving good self-cleaning properties. Therefore, the nanocomposite could be a promising futuristic material for many advanced applications.