Nanographene Oxide Functionalization with Organic and Hybrid Organic-Inorganic Polymers by Molecular Layer Deposition

Abstract

The functionalization of nanographene oxide (GO) with polymers is desirable for increasing the interface compatibility of GO, thereby enabling its use in a variety of applications such as biomedical and energy storage systems. Typically, wet chemistry processes are used to achieve polymer functionalization of GO, having limitations of high heterogeneity, time consumption, and difficult purification processes. Two approaches for dry functionalization of the nano-GO surface are therefore proposed, utilizing an atomic layer deposition (ALD) reactor: (1) vaporization-condensation of polyethylene glycol amine (PEG-NH2) and (ii) molecular layer deposition (MLD) of a polymer hybrid from trimethylaluminum (TMA) and ethylene glycol (EG). Carboxylic activated nano-GO (GO-COON) powders were exposed to PEG at variable temperatures, determining that a minimum of 100 degrees C was sufficient for adsorption of the polymer. In addition, a layer by layer deposition (an MLD route) is proposed to impart control over the growth of a polymer hybrid onto the GO COOH surface and to enhance the efficiency of polymer deposition by sequentially supplying a passivation layer, -Al- bonds, for monomer attachment. FTIR and XPS results showed effective control on the growth of the hybrid polymer at the GO COOH surface, achieved through optimization of ALD reactor experimental conditions.