Remarkable synergetic effect by in-situ covalent hybridization of carbon dots with graphene oxide and carboxylated acrylonitrile butadiene rubber

This work investigates the remarkable synergetic effect produced by in-situ covalent hybridization of carbon dots (CDs) with graphene oxide (GO) and carboxylated acrylonitrile butadiene latex (XNBR). The carboxylic acid groups of GO and XNBR latex have been covalently conjugated to surface amine groups of CDs following carbodiimide chemistry. The covalent conjugation in XNBR-CDs-GO hybrid nanocomposite has been confirmed by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). Transmission electron microscopy (TEM) and atomic force microscopy (AFM) images show the presence of covalently bonded CDs on the GO surface and also in the XNBR latex. The optical properties of the XNBR-CDs-GO hybrid nanocomposites have been characterized by ultraviolet (UV) – visible and fluorescence spectroscopy. The in-situ covalent hybridization of CDs with GO and XNBR latex increases the interactions between the nanofillers and the XNBR latex and also effectively prevents the stacking of GO sheets in XNBR latex. Covalently hybridized XNBR-CDs-GO nanocomposites display higher physico-mechanical properties and thermal stability when compared to XNBR-CDs and XNBR-GO nanocomposites.