Nanocomposite films and coatings produced by interaction between graphite oxide and Congo red

Nanocomposite films and coatings were produced from the aqueous solutions containing different proportions of graphite oxide (GO) and Congo red by filtering through a polycarbonate membrane filter into alkaline media. They were examined by electron microscopy, Raman and FTIR spectroscopy, XRD, contact angle, and electrical conductivity measurements. It was established that the Congo red is able to interact through its amino groups with different functional groups of GO to form larger moieties composed of the nanoplatelets of GO. Raman spectroscopy revealed quinoid-like ring structure for dye adhering to the GO. In the case when the interaction occurs with the terminal functional groups located on the edges of the nanoplateletes of GO, larger crystallites in the nanocomposite are formed. The interaction between the Congo red and functional groups of GO situated in a basal plane leads to more compact structure of the nanocomposite. Pulsed laser treatment was used to reduce GO to graphene. Raman spectra of laser treated areas show positive effect of addition of the Congo red on the graphene yield in nanocomposite coatings after the laser treatment.