Ceramics and Glasses Modeling by Simulations and Machine Learning: Poster Session
Sponsored by: ACerS Glass & Optical Materials Division
Program Organizers: Mathieu Bauchy, University of California, Los Angeles; Peter Kroll, University of Texas at Arlington; N. M. Anoop Krishnan, Indian Institute of Technology Delhi
Monday 5:00 PM
October 10, 2022
Room: Ballroom BC
Location: David L. Lawrence Convention Center
Session Chair: Mathieu Bauchy, UCLA
D-7: Development of Structural Descriptors to Predict Dissolution Rate of Volcanic Glasses: Molecular Dynamic Simulations: Kai Gong1; Elsa Olivetti1; 1Massachusetts Institute of Technology
Establishing the composition-structure-property relationships for amorphous materials is critical for many important natural and engineering processes, including the dissolution of highly complex volcanic glasses. Here, we performed force field molecular dynamics (MD) simulations to generate detailed structural representations for ten natural CaO-MgO-Al2O3-SiO2-TiO2-FeO-Fe2O3-Na2O-K2O glasses with compositions ranging from rhyolitic to basaltic. Based on the attributes of the resulting atomic structures and classical bond valence models, we have introduced a novel structural descriptor, i.e., the average metal-oxygen bond strength (AMOBS) parameter, which has captured the log dissolution rates of the ten glasses at both acidic and basic conditions (obtained from the literature) with R2 values of ~0.80-0.92 based on linear regression. This structural descriptor is seen to outperform several other structural descriptors also derived from MD simulations. The results suggest that structural descriptors derived from MD simulations are promising for connecting composition with dissolution rates of highly complex natural glasses.
D-8: Molecular Dynamic Simulations of Polymer Derived Ceramics: Harrison Chaney1; Kathy Lu1; 1Virginia Tech
Polymer derived ceramics are a promising class of materials. To establish relationships between the initial polymer composition and the end composition and structures of the ceramic, this work used LAMMPS in conjunction with the REAXFF module to simulate the polymer to ceramic conversion. Three different base polymer structures were selected based on the initial carbon compositions, consisting of polydimethylsiloxane (PDMS), polydiethylsiloxane (PDES), and commercially available SPR 684 polysiloxane (PSO). From these simulations, bonding information, final compositions, and microstructures were extracted. The final compositions correlate well with the initial compositions, but the relative carbon loss is higher for the higher carbon starting polymers especially that of PDES. The end structures for each have vastly different carbon domain sizes and carbon fractions. This work hopes to shed light on the effect that the starting polymer has on the final product and gain insight into what is happening on the atomic level.