(220f) Computational Investigations of the Effect of Electrostatic Environment on Silica Self-Assembly

Authors: 
Hare, S., University of Washington
Pfaendtner, J., University of Washington
While looking to Nature for synthetic inspiration is a useful practice, the complexity of such synthetic routes can make laboratory-based mimics difficult to rationally design. Computational modelling can be used to understand on a fundamental level how aspects of reaction environment cause certain reactions to occur. In particular, this work focuses on the self-assembly of silicic acid into silica oligomers, a process that is conducted by the protein silaffin to generate complex exoskeletons in marine organisms with impressive morphological control. While work has been done to understand the behavior of silica in “bio-inspired” environments (e.g., using a surface of peptides on which to grow silica), relatively little research has been done to understand how simple charged interfaces affect the condensation of silica. What has been shown thus far is that minor changes in electrostatic environment can significantly affect the morphology of the resultant silica structures. To probe this effect on a fundamental level, static DFT and molecular dynamics simulations in the gas phase and solvent were conducted on an idealized model system to determine (1) the effect of a charged interface on the energetics of the reaction network and (2) the dynamic behavior of the solution that leads to particular silica morphology. Understanding the effects of electrostatic environment on silica oligomerization in isolation could lead to better synthetic control in laboratory settings.