Ultrafiltration membranes with integrated adsorber properties via „click“ functionalization

Ultrafiltration membranes with integrated adsorber properties via „click“ functionalization


Water contaminations with heavy metals are one of the most dominant environmental problems society is facing nowadays. Generated through a rising number of processes like mining, fertilizing of soils or paper production many waters are loaded with high contents of harmful species. There are several processes to free water of pollutants like chemical precipitation, ion exchange, adsorption or electrochemical treatment. However most of these processes are only suitable for high amounts of pollutants, are very expensive or lead to secondary treatment of byproducts. Membrane processes have gained a high interest in the last years for wastewater treatment due to low operative costs and simple processes.

The aim of this project is to generate ultrafiltration (UF) membranes with additional adsorber properties, which show high affinities for targeted heavy metal ions or a broad spectrum of heavy metal ions depending on their functionalization. For this purpose polysulfone (PSU) as base membrane material is prefunctionalized with azidomethyl groups to allow a “click” reaction with functional polymers. These functional polymers have on the one hand alkyne groups suitable for 1,3-dipolar cycloaddition (Huisgen “click” reaction) to immobilize them on the surface covalently and on the other hand work as binding agents for metal ions. One approach is to functionalize commercially available, branched polymers like polyethylenimine (PEI) with suitable groups for immobilization. The other approach targets the synthesis of copolymers via controlled radical polymerization to obtain well defined linear polymers containing anchor groups suitable for “click” coupling and specific functional groups for selective metal ion binding. The functionalization of membranes prepared from PSU modified with azidomethyl groups is carried out via infiltration of an aqueous solution of the functional polymer with subsequent characterization in terms of UF membrane performance, static and dynamic adsorption capacities for metal ions as well as efficiency and stability of the generated membrane adsorber.


Funding: This work is part of the project POLINOM (grant number 03XP0106C), supported by the German Ministry of Education and Research (BMBF) as part of the “Materialien für eine nachhaltige Wasserwirtschaft – MachWAS

Dereck Koch