Complex crystal structures formed by the self assembly of di-tethered nanospheres

We report the results from a computational study of the self-assembly of amphiphilic di-tethered nanospheres using molecular simulation. As a function of the interaction strength and directionality of the tether-tether interactions, we predict the formation of four highly ordered phases not previously reported for nanoparticle systems. We find a double diamond structure comprised of a zincblende (binary diamond) arrangement of spherical micelles with a complementary diamond network of nanoparticles (ZnS/D); a phase of alternating spherical micelles in a NaCl structure with a complementary simple cubic network of nanoparticles to form an overall crystal structure identical to that of AlCu_2Mn (NaCl/SC); an alternating tetragonal ordered cylinder phase with a tetragonal mesh of nanoparticles described by the [8,8,4] Archimedean tiling (TC/T); and an alternating diamond phase in which both diamond networks are formed by the tethers (AD) within a nanoparticle matrix. We compare these structures with those observed in linear and star triblock copolymer systems.