Fabrication of polymer-brush modified Ba-Ti oxide/poly(vinylidene fluoride) nanocomposites thin film*

Polymer composite with high dielectric constant have attracted attention in the micro-electronic industry due to their easy-processing and low cost. In the composite thin film, the surface properties of the ceramics nanoparticle and the volume fraction of polymer to ceramics particles are quite important in order to increase in their functionality. In this study, the surface modification of Ba-Ti oxide nanoparticles (BT) with high-density poly-methyl methacrylate (PMMA) brushes was conducted to improve its dispersibility in poly(vinylidene fluoride) (PVDF) and the fabrication of nanocomposites thin film of PMMA-BT and PVDF was investigated. PMMA brushes on the surface of BT particles were fabricated by Atom Transfer Radical Polymerization with (2-bromo-2-methyl) propionyloxyhexyltriethxysilane as a silane coupling agent. PMMA-BT particles showed high dispersibility in PVDF-DMF and almost no voids and clacks were observed in the composite film of BT-PMMA mixed with PVDF even if the volume fraction of PMMA-BT particles was high to PVDF. The results indicated that the surface modification by polymer-brush could be a promising method to fabricate the composite film having good quality and high dielectric property.