Novel low-density structure for hard rods with adhesive end groups

A system of hard rods with mutually attractive or sticky ends is investigated with the help of Monte Carlo simulations. For low strengths of the attractive interaction, the system behaves qualitatively similar to a hard rod system. At low densities and sufficiently high adhesive strengths, a novel scaffold-like phase is found, which is characterized by a large number of triangles formed by three mutually adhering rods. For a moderate adhesive strength, the scaffold structure is rather flexible, as revealed by lifetime measurements of adhesive contacts. At higher pressure and high adhesive strength, the system forms small smectic-like bundles. At pressures for which the hard rod system becomes nematic, the rods with attractive ends form a smectic A phase, if the adhesive strength is large enough.