Silica-polypyrrole core-shell nanocomposites as active materials for dielectrophoretic displays

A direct route to silica-polypyrrole core-shell nanoparticles has been used to design new nanocomposites, in which the conducting part is then wrapped by an external silica shell in order to have finally neutral nanoparticles. The nanocomposites are characterized by TEM, spectroscopy, electrochemistry and thermal gravimetric analysis, demonstrating that the external silica shell actually insulates the conjugated polymer from the outer medium. Finally the electrorheological properties of these nanocomposites are checked in a dielectrophoretic device in which the motion of the particles induced by an external electric field can be used to monitor a switch of the light transmission properties.