ABSTRACT
Solvent resistant nanofiltration (SRNF) is the branch of membrane technology that focuses on the separation of products smaller than 1000 Da from organic solvents. SRNF is a fairly new field, with the earliest publications around the 1990s. The polymer-lean phase will start to form nuclei and will withdraw more and more liquid from the polymer-rich phase. This process will continue until thermodynamic stability is re-established. Surfactants affect the interfacial properties between the polymer solution and the coagulant and influence the phase inversion. The addition of surfactants can enhance the affinity between solvent and non-solvent, resulting in a shift from delayed demixing to instantaneous demixing. Metal oxides can be introduced to the polymer solution as another macrovoid suppressor, as they increase the viscosity of the polymer solution, slow down the solvent and non-solvent exchange rate and impose delayed demixing. Gold, silver and copper especially exhibit unique and tunable optical properties due to their surface plasmon resonance.
