Synthesis of aggregate and non-aggregate reduced graphene oxide lamellar membrane for application in nanofiltration

ABSTRACT

The present work aimed to synthesize lamellar membranes of reduced graphene oxide (rGO) on a cellulose acetate substrate and to compare them for the rejection of aniline blue, using two different rGO production methodologies: aggregating and non-aggregating reduction. Initially, dispersions of graphene oxide (GO) were produced by a modification of the Hummers method, which underwent thermochemical treatment to reduce GO and were used for deposition on a cellulose acetate substrate, using the vacuum-assisted filtration method. To characterize the dispersions and membranes, X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques were used, and stability tests in water were conducted on the produced membranes. To analyze the rejection of aniline blue, used as the material to be filtered, the permeates of each of the membranes, as well as the substrate as received, were analyzed by UV-Vis spectrophotometry, and the concentration of the permeate could be estimated from of a previously produced calibration curve. Significant differences in membrane stability were observed, depending on the reduction methodology used, as well as an expressive increase in the rejection of aniline blue in relation to the substrate as received from cellulose acetate.

Keywords
Membranes; graphene; nanofiltration; water