Barium titanate nanoparticles in block copolymer

Cubic BaTiO3 particles of similar to 10 nm were crystallized predominantly within the hydroxylated polybutadiene matrix of a phase separated triblock copolymeric thin film of polystyrene-polybutadiene-polystyrene (Kraton D110 2). The barium titanated Kraton thin film had remnants of the cylindrical m orphology of a plain Kraton thin film with an interdomain spacing of simila r to 23 rim. The procedure of barium titanation consisted of three steps: ( 1) in situ hydroxylation of the polybutadiene matrix of an annealed Kraton thin film, (2) regioselective deposition of barium titanium methoxypropanox ide (BaTi(OCH2CH(CH2)OCH3)(6)) on the hydroxylated polybutadiene matrix, an d (3) hydrothermal. reduction of the organometallic complexes in an NH3/H2O atmosphere at 80 degreesC for 24 h. Isolated water clusters in step 3, con densed from the NH3/H2O atmosphere of 1 M NH4OH(aq) at 80 degreesC in the a lkoxide-Kraton films, were believed to have a typical diameter of no more t han 23 nm at a pH of 14. They gave a high pH environment to weaken the chel ating effect among alkoxides and the organic matrix and provided a spatial confinement for the localized nucleation and growth of cubic BaTiO3 nanopar ticles.