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Membrane technology is becoming increasingly more important in current society. Membranes are used widely in wastewater treatment and water purification, where it has become a dominant technology. However, when solvents are present in aqueous streams, these membranes tend to lose their separation capacities, due to swelling and degradation. This hinders implementation of membrane technology into streams containing both solvents and water. During this dissertation, a novel type of nanofiltration (NF) membranes will be developed that can remain stable in solvent/water mixtures and in addition show a high performance. This novel type of NF-membranes consists of an epoxy-based selective top-layer, synthesized via interfacial polymerization. The focus of this dissertation will be on developing these epoxy-based thin film composite (TFC) membranes on two different solvent stable support layers. In a first segment, crosslinked polyimide (PI) was chosen as support layer. After some preliminary tests, a first series of TFC membranes were developed on these crosslinked polyimide supports. These membranes were tested on different solvent/water mixtures. Results showed a successful proof of concept and in a following series of tests further optimization was conducted. This increased the overall performance of these membranes, with an average rose bengal (RB) retention above 90% and an average permeance of 0.5 L/m²*h*bar. In a final test, the membranes were immersed in an activation solvent, resulting in a near doubling of the membrane permeance without loss of retention. Secondly, crosslinked polyacrylonitrile (PAN) was investigated. Like PI, a first series of TFC membranes were developed and once again, first results showed a successful proof of concept. Further optimization resulted in good performing TFC membranes, with the best membrane showing a retention of 91% RB, with a permeance of 4.5 L/m²*h*bar. Further optimization of these membranes was hampered due to inconsistent results and an attempt was made to find the cause of this problem. A final segment of this dissertation focused on finding a greener alternative for one of the solvents (toluene) used during the synthesis process of these membranes. After calculating Hansen solubility parameters and solubility tests, one solvent (diethyl carbonate) was chosen and tested. Results indicated diethyl carbonate could potentially be used as a green alternative to toluene.