UNL Noticias

Se informa a la comunidad UNL la realización del seminario del Dr. Igor Stanković, el miércoles 3 de julio a las 11 horas en el Auditorio del Edificio Bernardo Houssay, ubicado en Güemes 3450, Santa Fe (Argentina).

Summary

This presentation delves into the intriguing world of small molecules and their collective dynamics, offering insights into their behavior in diverse nanoscale systems. Graphite and graphene, are two remarkable carbon-based materials, that have been at the forefront of a revolution in the fields of energy storage and two-dimensional electronics. Graphite, a layered material composed of stacked graphene sheets, has long been used as the anode material in conventional lithium-ion batteries. However, the quest for higher energy density and faster charging capabilities has driven researchers to explore novel electrolytes and modifications of graphite. Graphene, the single-layer counterpart of graphite, comprises a honeycomb lattice of carbon atoms. Graphene is incredibly thin, lightweight, and possesses outstanding electrical conductivity. This talk presents three examples where molecular dynamics simulations were combined with state-of-the-art experiments to reveal the fascinating diversity of collective interactions of small molecules in contact with carbon-based layered materials. At the largest scale, we challenge conventional paradigms by investigating friction mechanisms in hydrophobic contact with highly ordered pyrolytic graphite HOPG [1]. Through a combination of experimental investigations and molecular dynamic simulations, we introduce a novel mechanism involving the agglomeration dynamics of water droplets, resulting in the formation of larger droplets within sliding nano-contacts. The second study focuses on the intercalation mechanism of aluminum fluoride (AlF3), a small molecule, into graphite electrodes in rechargeable aluminum batteries [2]. By employing scanning tunneling microscopy, density functional theory calculations, and large-scale molecular dynamics simulations, we unravel the collective dynamics of AlF3 clusters between graphite layers. In previous examples, we saw how electric dipole moments of molecules influence the mechanical and functional properties of graphite. In the final part of the talk, we demonstrate how molecular dynamics simulations can reproduce geometry and conditions close to experimental for ferroelectric switches using water adsorbed on oxygenated graphene edges [3].

[1] O. Noël, P.E. Mazeran, and I Stankovic Nature of dynamic friction in a humid hydrophobic nanocontact, ACS Nano 16 (7), 10768-10774 (2022).

[2] S.J. Rodríguez, A.E. Candia, I. Stanković, M.C.G. Passeggi, and G.D. Ruano, Study of in-plane and interlayer interactions during aluminum fluoride intercalation in graphite: implications for the development of rechargeable batteries, ACS Applied Nano Materials, 6 (18), 16977-16985 (2023).

[3] M.A. Aslam, I. Stankovic, G. Murastov, A. Carl, Z. Song, K. Watanabe, T.zTaniguchi, A. Lugstein, C. Teichert, R. Gorbachev, R. D. Rodriguez, and A. Matkovic, Water Induced Ferroelectric Switching: The Crucial Role of Collective Dynamics, submitted to Nano Letters, arXiv preprint arXiv:2304.09738.

El Dr. Stanković investiga en el Laboratorio de Computación Científica del Centro para el Estudio de Sistemas Complejos, perteneciente al Instituto de Física de Belgrado, Serbia. Su trabajo se enfoca en  las correlaciones entre la estructura y las características de transporte de gases, líquidos y sólidos. Utiliza la física estadística para establecer conexiones entre las propiedades macroscópicas de la materia y las propiedades microscópicas de sus constituyentes. Los campos de investigación de su interés son: el transporte en medios porosos, el modelado multiescala, la fricción seca en metales y las aleaciones mecánicas. Los métodos de trabajo utilizados son los siguientes: simulaciones mediante dinámica molecular, teoría cinética, termodinámica irreversible y soluciones analíticas y numéricas.

Fuente: https://ifis.conicet.gov.ar/molecular-dynamics-simulations-of-small-molecules-on-carbon-based-layered-materials/