Membrane technology is widely used to separate substances from each other. For example, it can allow water to pass through, but it filters out bacteria. This technology saves water and energy, and has small CO2 footprint. Unfortunately, because of toxic solvents used in membrane production, a green alternative to current production is urgently needed. The current method can have adverse effects on human health and the harmful solvents are very difficult to remove from the wastewater and the membrane itself. Vidi researcher Wiebe de Vos is working on a clean alternative, and he has developed a new production method that is not only safe for the environment, but it allows a production of even greater variety of membranes.
De Vos’s method is called Aqueous Phase Separation and is based on charged polymers. “We prepare a solution of two different polymers with a high pH value. Under those circumstances, one of the two polymers is negatively charged, the other is still neutral. By immersing a film of this solution in an acidic bath, the second polymer gains a positive charge. The oppositely charged polymers attract each other and cluster, forming a new complex material. This complex material then precipitates as a porous film: the membrane. The speed at which the polymers cluster determines the final structure of the membrane. The faster the clustering, the smaller the holes. By varying parameters like the composition and concentration of the two polymers, or the acidity of the solutions, you can create different types of membranes according to your needs.”
We are looking forward to learning more about the future of water treatment at WieTec 2020 International Smart Water Forum. Our event is to be held on 3- 4 June 2020 at Shanghai Exhibition and Convention Center.