Membranes play a critical role in the production of safe drinking water and in the treatment of human waste streams. However, membranes themselves are nearly always produced using costly, harmful and environmentally unfriendly aprotic solvents such as N-methyl-pyrrolidone (NMP). This project investigates a highly novel approach allowing the production of the next generation of advanced membranes without the need to use any organic solvents. Here, the complexation of positively and negatively charged polyelectrolytes will be the basis for a new method for the fabrication of membranes, requiring only water as a solvent. The charged nature of these starting materials will make these membranes especially promising as the next generation of Nanofiltration (NF), Electrodialysis (ED), and Solvent Resistant Nanofiltration (SNRF) membranes. Finally, blending the polyelectrolytes with active ingredients can provide the membrane with advanced properties (anti-fouling, ion-specific, catalytic etc.). Concrete objectives or the SAMBA project are the successful development of this sustainable approach to membrane production and a demonstration that these membranes can be used in relevant membrane processes, including oily waste water treatment, protein concentration and micro-pollutant removal.