Preparation of graphene oxide (GO) membranes with potential application in water desalination

The desalination is one of the most promising approaches to mitigate the water shortage increasing the water supply beyond what is available in the world. Reverse osmosis and multistage flash distillation has been mainly used to seawater desalination, however these processes consume large amounts of thermal and electric energy [1]. Some studies have demonstrated that graphene-like membranes can be used for this purpose due to their chemical and mechanical stability and also high fluid permeability and ion rejection rate [1]. In this work, multilayer structures formed by porous GO have been prepared and investigated for their ability of ionic and molecular separation. The GO membranes with controlled thickness were prepared using chemical route involving acids and microwave radiation. These membranes were characterized by X-ray diffractometry (XRD), infrared spectroscopy (FTIR), thermogravimetry (TG-DTA) and scanning electron microscopy (SEM) (Figure 1). The GO membranes with 350 nm of thickness deposited on commercial polyvinylidene fluoride (PVDF) showed good thermal stability and an interplanar distance of 0.74 nm. According to literature, these results demonstrate the potential to application as ionic and molecular sieves. The deionized water flux across the GO membrane measured was 35.6 Kg m-2 h-1. New experiments of water permeability and salt rejection, evaluated by ionic conductivity in solution, are now in progress.