Dielectric properties of polymer nanoparticle composites

Well-dispersed high dielectric permittivity titanium dioxide (TiO2) nanoparticles were synthesized utilizing a block copolymer as a template. The nanoparticles were confined within microphase separated domains of sulfonated styrene-b-(ethylene-ran-butylene)-b-styrene (S-SEBS) block copolymers. A crosslinker (vinyltrimethoxysilane) was incorporated into the block copolymer matrices in order to decrease the dielectric loss from the free sulfonic acid groups. Dynamic mechanical analysis experiments confirmed that nanoparticles and crosslinker were confined within the crosslinked sulfonated styrene blocks and had no effect on the chain relaxation behavior of [ethylene-ran-butylene] blocks. Dielectric experiments showed that higher permittivity composites can thus be obtained with a significant decrease in loss tan δ (<0.01) when crosslinked with vinyltrimethoxysilane.