Graphene-based filters operate through two primary mechanisms: size exclusion and chemical affinity. In size exclusion, the nanoscale pores in the graphene oxide membrane are small enough to block larger particles while allowing smaller molecules like water to pass through. Chemical affinity, on the other hand, involves the interaction between the contaminants and the functional groups on the graphene oxide. These interactions can either attract or repel specific molecules, enhancing the filter's efficiency.
