(227a) A Celebration of My 15+ Year Collaboration with Peter Monson on Simulating the Self Assembly of Nanoporous Materials: Are We Sipping from the Holy Grail?

Zeolites are the most used catalysts by weight on earth and offer the potential for new applications in carbon dioxide capture, biofuel production, and nano-electronics. The applications of zeolites arise from their nanoporous crystalline structures and stabilities. Despite the great importance of zeolites, zeolite chemists still rely heavily on trial-and-error in their search for new materials, because the mechanisms controlling zeolite formation remain poorly known. Understanding such mechanisms will be critical to one of the "holy grails" of materials science -- rational design of tailor-made nanoporous materials. In this lecture, I celebrate my 15+ year collaboration with Peter Monson by sharing the story of the development of a multi-scale molecular modeling program in search of this holy grail.

I begin by reviewing present-day understanding of zeolite synthesis with a focus on the role of "structure directing agents" (SDAs). Peter and I have studied this problem through a multi-scale application of Density Functional Theory (DFT) and Monte Carlo (MC) methods. Our DFT calculations provide key structural and energetic parameters, and explain the curiously wide range of bulk moduli observed for silica polymorphs. Our MC simulations of silica polymerization have elucidated the formation of amorphous silica, silica-SDA nanoparticles, zeolites, and mesoporous silica. Here I emphasize the uniqueness and power of Peter’s research vision in developing both insightful models and efficient simulations. Our MC simulations reproduce NMR signatures of silica polymerization; predict that such polymerization is not diffusion controlled; and reveal sought-after structures of silica-SDA nanoparticles. Replica exchange MC is found to be essential for modeling zeolite crystallization, allowing predictions of SDA sizes that optimize zeolite yield and crystallization rate. I conclude with remarks about the potential for molecular modeling to peer even more deeply into the atomic dance of nanopore formation, a potential largely created by the brilliance of Peter Monson.