Force Field Development for Porous Media .
Speaker: Sofía Calero (UPO Spain)
Time: Feb. 14, 2019, 10:00–11:00
Location: Differ, Alexander-zaal
Molecular simulation plays an important role in the field of porous materials. The use of molecular simulations allows the prediction of molecular adsorption and diffusion in these materials and also provides important information about the processes taking place inside the porous structures at the molecular level.
The advantage of using computational approaches is that simulations provide unique microscopic insight and total control on the conditions. In addition, simulations, allow the study of hypothetical structures, can be used as a prediction tool, and are an excellent complement to the experimental work. Current research on molecular simulation in porous materials faces on-going challenges such as the development of good and realistic in silico models and accurate force field potentials as well as fast and efficient methods to adequately integrate diffusion and adsorption. This would lead to the prediction of properties of new high-performance materials with increasing efficiency and speed.
The development of transferable potentials for porous crystalline materials remains a formidable task, especially for Metal Organic Frameworks for which the structural diversity acts as a severe disadvantage. There are two main challenges in fitting a force field to experimental data:
- the choice of experimental data that are used in the fitting and in the validation steps,
- the nature of the parameter fitting method.
Especially the latter is a remarkable challenge since all force field parameters have to be fitted simultaneously and the number of parameters can be quite large. Several methods have been proposed for the fitting procedure all of them requiring a large number of time-consuming simulations. Over the last ten years we have been developing models for fast estimation of these force field parameters in order to reproduce structural phase transitions as well as the adsorption and diffusion of molecules in crystalline porous materials. The advantage of these models is that they can be used for a large variety of molecules (taking into account also dipolar and quadrupolar interactions) and be transferred to most zeolite structures and to many Metal-Organic Frameworks.