Ferrocene-Containing Inverse Opals by Melt-Shear Organization of Core/Shell Particles

In this work, the preparation of redox-responsive elastomeric inverse opal films featuring switchable structural colors is reported. The pristine core/shell particle architecture consists of a silica core having a metallopolymer shell, that is, poly(2-(methacryloyloxy)ethyl ferrocene carboxylate) (PFcMA) copolymerized with n-butyl methacrylate (PFcMA-co-PnBuMA) synthesized via seeded and stepwise emulsion polymerization protocols. This tailor-made, inorganic core/hybrid organic shell architecture leads to monodisperse particles, which were then subjected to the so-called melt-shear organization technique. After a cross-linking reaction and the core particle removal, vivid structural colors are obtained due to the well-ordered voids within the metallopolymer-containing matrix. In addition, redox responsiveness is shown by the addition of chemical oxidation and reducing agents as well as by cyclic voltammetry studies, thus revealing both a change of surface wettability and a change of the structural reflection colors. Herein, the described one-pot strategies for the preparation of metallopolymer-containing core/shell hybrid particles and application of the melt-shear ordering technique paves the way to novel redox-responsive porous opal films, which are expected to be promising materials in the field of remote-switchable sensors or electrochemical adsorbents.