Effect of graphene on self-healing performance of hydroxyapatite/polydimethysiloxane composites

Recently, polymeric self-healing materials are tremendously being exploited in the fields of biomedical and other advanced engineering applications. However, mechanism of the self-healing materials is not very clear and the healing performance is very poor for the existed materials. Therefore in our present investigation, hydroxyapatite (HA) bioceramic, graphene (Gr) and polydimethysiloxane (PDMS) were used to develop a high performance novel self-healing composite. Here, we proposed a single step accessible preparation of short-layers graphene by the exfoliation of graphite layers via acid leaching method. Further, Gr/HA embedded PDMS membranes were prepared using a vascular method. We prepared the PDMS elastomer (resin:hardener ratio = 1:1) being mixed with 2 wt% HA and varying concentrations 0.1 wt%, 0.3 wt%, 0.5 wt% of Gr. The band gap, phase structure, crystalline and chemical structure of the Gr/HA composite films were characterized using UV-Vis, XRD and FTIR studies. A series of tensile tests were conducted to measure virgin and healed tensile specimens. The highest mechanical property was achieved at 2 wt% of HA. But best self-healing performance of the 0.1 wt%Gr composite was obtained from the recovery of tensile properties. The healing efficiency was found to depend on the curing properties of PDMS varied with HA/Gr reinforcement and quantity of healing agent delivered.