(18d) Oriented Motions of Gibbsite Particles during Self-Assembly

Before one particle attaches to another during self-assembly, they experience multiple motions, including translation, rotation, and approach. The forces driving these motions, the changes in the energy landscape during these motions, and how these motions effect the final structure of self-assembly are some of the important research topics. Here we use molecular dynamics simulation to unravel the directional energy-structure relationships during rotation, translation, and approach of particles. In particular, we used molecular dynamics simulations to calculate the potential of mean force for the relative motions of gibbsite particles. We consider multiple translational directions (e.g., along a- and b-axes) and crystal facets (basal and edge). Our results reveal that (1) basal-basal gibbsite surface attachment is more favorable than basal-edge, and edge-edge attachments, (2) translation toward alignment along the b-axis [or (0 1 0) direction] can be more energetic favorable than translation along the a-axis [ or (1 0 0) direction]. This work provides the energy–structure relationships during particles relative motions to understand the crystal face selectivity and alignment pathway selectivity of OA.

Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.