A Multiscale Molecular Simulation Approach to Designing DNA Decorated Colloids for Double Gyroid Self-Assembly*

Submitted for “ 50 years of Gyroid structures in materials and tissues - in honor of Alan Schoen.”

The gyroid phase is one of the most interesting and feature rich mesophases, with potential applications in photonic crystals, solar cells, and separation and catalytic membranes. Gyroidal sructures are of interest for different applications, which has fueled interest in developing different types of building blocks to achieve them. Inspired by previous modeling studies, in this simulation work we focus on developing colloidal particles as building blocks and take advantage of hybridizing DNA strands grafted to nanoparticle surfaces to design effective interactions that lead to the self-assembly of the double gyroid phase. We achieve this in a two-component system through judicious control of DNA patterning designs, DNA chain lengths and relative contact interaction distances. Our approach is iterative and entails multiscale models wherein for each proposed design: (i) a detailed model is used to obtain effective pair-particle potentials, (ii) a highly coarse-grained, many-particle system is simulated to characterize its self-assembly behavior, and (iii) the stability of gyroid-forming systems are validated through detailed many-particle simulations. The results are fed into a machine learning model to aid the exploration of the design space of our colloids. Through this process we demonstrate the self-assembly of the double gyroid phase and delineate the design rules needed to induce its formation.