Polymersome/Silica Capsules by ‘Click’‐Chemistry

Polyisobutylene/poly(ethylene oxide) diblock copolymers (PIB n ‐PEO m ) with variable block‐lengths ( n = 40, 75; m = 31, 52) have been prepared by a combination of living polymerization cationic methods and azide/alkyne ‘click’ chemistry. Allyl‐telechelic PIBs are transformed into the respective telechelic PIB‐azides (PIB‐N 3 ) by a quantitative procedure. Coupling of the PIB‐N 3 to acetylene‐telechelic PEO‐polymers is then quantitatively achieved by a Cu I ‐mediated cycloaddition reaction. The resulting diblock copolymers reveal lamellar structures in solution at concentrations up to 35 wt.‐%, whereas polymersomes are formed at lower concentrations. The resulting polymersomes can be silicified under inclusion of nanoparticles to generate micrometer‐sized, multifunctional capsules with a silica shell. magnified image