Giant Free-Standing ABA Triblock Copolymer Membranes

For the first time giant free-standing monomolecular films of a functionalized poly(2-methyloxazoline)-block-poly(dimethylsiloxane)-block-poly(2-methyloxazoline), PMOXA-PDMS-PMOXA, triblock copolymer were prepared. Stable films with areas up to about 1 mma and thickness of 10 nm were achieved. This triblock copolymer carries polymerizable methacrylate groups at both chain ends. These end groups could be polymerized by UV light after the formation of the self-assembled structure. The mechanical properties of these films were characterized by applying short electric field pulses. In comparison to lipid bilayers, the polymer films were significantly more cohesive, seen by higher critical voltages required for rupture. Moreover, polymerization increased the stability significantly.