Effect of Valency on the Dynamics and Thermodynamics of DNA-linked Nanoparticles Materials
Nanoparticles (NP) functionalized with single-stranded DNA (ssDNA) offer a route to custom-designed, self-assembled nanomaterials with potentially unusual properties. We explore the phase behavior and structure of a model for NP functionalized with between 3 and 6 short ssDNA through simulations, allowing us to examine both the role of the number of attached strands (valency) and their relative orientations. We find that 3 to 5-functionalized NP form amorphous systems, with 4 and 5-functionalized NP constructing an unusual multitude of liquid phases, or polyamorphism, through interpenetration of networks. The 6-functionalized NP with octahedral symmetry form at least six crystalline structures, consisting of up to six interpenetrating simple cubic lattices. The crystallization dynamics of the 6-functionalized system follows the conventional two-step pathway, demonstrating that such mechanism applies to our NP system with complex interactions.