Emergence of Zeolite Analogs and other Microporous Crystals in an Atomic Lattice Model of Silica and Related Materials.
The potential of tailored nanopores to transform technologies such as drug delivery, biofuel production, and optical-electronic devices depends on fundamental knowledge of the self-assembly of ordered nanoporous solids. Atomic-level geometries of critical nuclei that lead to such solids have remained hidden in the nanoscale blind spot between local (<0.5 nm) and collective (>5 nm) probes of structure. Heroic efforts at molecular simulation of nanopore formation have provided massive libraries of hypothetical structures; (1-5) however, to date no statistical simulation has generated a crystallization pathway from random initial condition to ordered nanoporous solid, until now. In this work, we show that a recently developed atomic lattice model of silica and related materials can form ordered nanoporous solids with a rich variety of structures including known chalcogenides, zeolite analogs, and layered materials. We find that whereas canonical Monte Carlo simulations of the model consistently produce the amorphous solids studied in our previous work, parallel tempering Monte Carlo gives rise to ordered nanoporous solids. The utility of parallel tempering highlights the existence of barriers between amorphous and crystalline phases of our model. Moreover, the self-assembly or nanoporous crystalline phases in the model open the door to detailed understanding of nanopore nucleation.
†Department of Chemical Engineering and ‡Department of Chemistry, University of Massachusetts, Amherst, Amherst, Massachusetts 01003, United States.
Lin
L
Jin
†Department of Chemical Engineering and ‡Department of Chemistry, University of Massachusetts, Amherst, Amherst, Massachusetts 01003, United States.
Scott M
SM
Auerbach
†Department of Chemical Engineering and ‡Department of Chemistry, University of Massachusetts, Amherst, Amherst, Massachusetts 01003, United States.
Peter A
PA
Monson
crystalline; nanoporous materials; parallel tempering Monte Carlo; self-assembly