NANOSCALE PATTERNING OF BARIUM-TITANATE ON BLOCK-COPOLYMERS

A triblock copolymer of polystyrene-polybutadiene-polystyrene (Kraton D1102) has been used to pattern barium titanate precursor with nanosca le modulations. The copolymer self-assembles to yield cylindrical poly styrene nanodomains in a polybutadiene matrix. The preorganized thin f ilms of polymer are then selectively OH-functionalized in situ on the unsaturated carbon bonds in the polybutadiene matrix with antistereoch emistry. Anchoring the barium titanate precursor onto the hydroxylated polymer thin films is possible only in the trans-1,2 polybutadiol mat rix through the condensation between the barium titanium double alkoxi des and the hydroxyl groups. The regioselective deposition of the bari um titanium double alkoxides on the original polybutadiene matrix of t he Kraton thin films was verified by transmission electron microscopy and electron energy loss spectroscopy. The spacing of the coordinated barium titanium double alkoxide pattern was similar to 23 nm, equivale nt to the interdomain spacing of the original polybutadiene matrix.