Polymeric membranes are one of the mostly widely used separation materials in both laboratory and industry. Surface modification is a common method to engineer polymer-based membranes for specialized applications, but is rather limited when it comes to adding functional units beyond simple molecules.

Using a copper-catalyzed azide-alkyne cycloaddition (CuAAC) “click” reaction, Morten Meldal, University of Copenhagen, Denmark, Mariusz Grzelakowski, Applied Biomimetic A/S, Nordborg, Denmark, and colleagues have developed a new strategy to immobilize polymersomes on nanoporous polymeric membrane surfaces. Polymersomes are artificial vesicles made from block copolymers.

The team subjected polyacrylonitrile (PAN) membranes to hydrochloric acid hydrolysis, which produced carboxylate groups on the surface. The carboxylates were then reacted with propargylamine, resulting in the desired alkyne groups for the click reaction. The researchers were able to covalently coat the functionalized PAN membranes with a monolayer of azide-functionalized polymersomes.

Since polymersomes are structurally similar to lipid vesicles, the method may be used to prepare cell membrane mimics. Considering the broad compatibility and simplicity of the CuAAC reaction, this work could also provide a solution for conveniently integrating new functionalities into common membranes.

• Click-chemistry of polymersomes on nanoporous polymeric surfaces,
  Christian Rein, Steen Nissen, Mariusz Grzelakowski, Morten Meldal,
  J. Polym. Sci. Part A Polym. Chem. 2016.
  DOI: 10.1002/pola.28069