Anisotropic self-assembly of nanoparticles in composites

An anisotropic self-assembled structure comprising a plurality of substantially isotropic grafted nanoparticles in a polymeric matrix, the self-assembled structure comprising

• (a) a one-dimensional string of the grafted nanoparticles within the matrix, the string having a width of one nanoparticle and a length of 1-10 nanoparticles,
• (b) a substantially two-dimensional sheet of the grafted nanoparticles within the matrix, the sheet having a length and a breadth of at least one micron respectively, wherein the sheet is about 2-5 nanoparticles in thickness, or
• (c) a plurality of three dimensionally interconnected structures where the width of each of the structures is 1-10 nanoparticles;
• wherein each grafted nanoparticle comprises a substantially spherical inorganic core nanoparticle and an organic brush structure grafted thereto, wherein
• the brush structure comprises a plurality of grafted polymeric chains of a weight average molecular weight Mg,
• the polymeric matrix has a weight average molecular weight of M, and
• there is an average number of grafted polymeric chains per nm2 of surface of the inorganic core nanoparticles D.