Additives and Post Treatments to Enhance Graphene Oxide Membrane Desalination

Water is a natural source vital for a sustainable society. However, given climate change and population growth natural water source are being depleted. Therefore, seawater desalination may provide potable water. This can be performed by using membrane technology. Traditionally, these membranes are polymer-based. Unfortunately, they are prone to fouling and can exhibit low chemical stability, therefore, alternative membranes are needed. Graphene oxide (GO) is 2d-material that can be produced in large quantities and is easy to handle. We have developed an original method to make GO membranes by spray-coating. Over the course of six years, we have modified graphene oxide membranes by adding nanomaterials and surfactants, and with post treatments such as heating, plasma, divalent ion cross linking and solvent hydration. The data consists of a wide range of desalination performance from 40% to 90% NaCl rejection and permeate flux between 0.2 and 1 m³m^-2day^-1, therefore GO membrane desalination is highly sensitive to the preparation method. In this work, we performed a statistical analysis on the obtained results to determine the most relevant factors for GO membrane desalination. For flux, the added nanomaterials and concentration exhibit the highest impact; and for salt rejection the GO concentration, number of coats and post treatment have the highest correlation. The identification of the most relevant parameters may serve as a guide to design GO membranes with higher desalination performance.