Scripting approach in hybrid organic-inorganic condensation simulation: the GPTMS proof-of-concept

Marek Maly (1, 2) , Paola Posocco (3) , Maurizio Fermeglia (3) , Sabrina Pricl (4)

1 Department of Physics
2 Institute of Chemical Process Fundamentals
3 Department of Chemical Engineering
4 Department of Chemical Engineering

Silica-based hybrid organic-inorganic materials prepared by sol-gel chemistry exhibit unique chemical and physical properties by virtue of their anisotropic organization. (3-glycidoxypropyl)trimethoxysilane (GPTMS)-based networks represent an archetype of this class of substances, with a vast range of applications. In the present study, a new computational recipe has been developed within Materials Studio software platform to generate atomistic models of GPTMS crosslinked networks. The methodology is based on molecular mechanics/dynamics schemes and assumes close proximity as a criterion for crosslinking reaction to occur. The COMPASS force-field was selected for molecular model constructions, and two charge schemes – one obtained directly from the force field and one derived from quantum-chemical calculations – were employed and compared for the prediction of the final system thermophysical properties. Starting from fully-hydrolyzed GPTMS molecules, a realistic three-dimensional network was successfully constructed, including the presence of 4- and 6-membered cyclic structures. Mechanical moduli and specific heat values estimated from equilibrated structures were selected as benchmarks for model/procedure validation. Overall, the simulation results are reasonable and in the range of experimental data available on similar system. Thus, the proposed computational strategy has a good potential in the design and optimization of organic-inorganic hybrid materials.

Mots clés: Physical Sciences

Marek Maly, Paola Posocco, Maurizio Fermeglia, Sabrina Pricl. Scripting approach in hybrid organic-inorganic condensation simulation: the GPTMS proof-of-concept. Molecular Simulation, 2008, 34 (10-15), pp.1215-1236. ⟨10.1080/08927020802235706⟩. ⟨hal-00515044⟩