Click Dielectrics: Use of 1,3-dipolar cycloadditions to generate diverse core-shell nanoparticle structures with applications to flexible electronics.

Improved high K dielectric materials are important for the development of devices for use in flexible electronics. One method of creating flexible high K materials is through the use of inorganic oxide core-polymer shell nanoparticles. In order to rapidly create a diverse array of such core-shell nanoparticle dielectrics, we have developed a novel surface ligand incorporating a phosphonate surface anchor and a terminal alkyne moiety. TiO2 nanoparticles coated with this ligand exhibit excellent dispersibility in organic solvents. The alkyne functional periphery permits chemical modification of the surface of these particles with diverse polymer shells using click chemistry, i.e. Cu-catalyzed azide-alkyne cycloaddition (CuAAC) reaction. Acrylate, styrenic and poly(acrylic acid) shells have been constructed around titanium oxide cores. The resulting core- shell polymer-nanoparticle structures can be spin cast or dropcast into films. The dielectric properties of the resulting nanoparticle- polymer composites have been studied for potential as high K dielectric materials for flexible electronics applications.