Multistep kinetic self-assembly of DNA-coated colloids

Abstract

Self-assembly is traditionally described as the process through which an initially disordered system relaxes towards an equilibrium ordered phase only driven by local interactions between its building blocks. However, This definition is too restrictive. Nature itself provides examples of amorphous, yet functional, materials assembled upon kinetically arresting the pathway towards the ground state. Kinetic self-assembly is intrinsically more flexible and reliable than its equilibrium counterpart, allowing control over the morphology of the final phase by tuning both the interactions and the thermodynamic pathway leading to kinetic arrest. Here we propose strategies to direct the gelation of two-component colloidal mixtures by sequentially activating selective interspecies and intra-species interactions. We investigate morphological changes in the structure of the arrested phases by means of event driven molecular dynamics (MD) simulations and experimentally using DNA-coated colloids (DNACCs). Our approach can be exploited to finely tune the morphology of multicomponent nano- or micro-porous materials with possible applications in hybrid photovoltaics, photonics and drug delivery.