Mechanical Properties of Schwarzites - A Fully Atomistic Reactive Molecular Dynamics Investigation
- PDF / 1,247,814 Bytes
- 6 Pages / 432 x 648 pts Page_size
- 99 Downloads / 217 Views
MRS Advances © 2018 Materials Research Society DOI: 10.1557/adv.2018.124
Mechanical Properties of Schwarzites - A Fully Atomistic Reactive Molecular Dynamics Investigation Cristiano F. Woellner1,2, Tiago Botari1, Eric Perim1, and Douglas S. Galvão1,2 1
Applied Physics Department, State University of Campinas, 13083-859 Campinas-SP, Brazil
2
Center for Computational Engineering & Sciences, State University of Campinas, Campinas-SP, Brazil
ABSTRACT
Schwarzites are crystalline, 3D porous structures with a stable negative curvature formed of sp2-hybridized carbon atoms. These structures present topologies with tunable porous size and shape and unusual mechanical properties. In this work, we have investigated the mechanical behavior under compressive strain and energy absorption of four different Schwarzites. We considered two Schwarzites families, the so-called Gyroid and Primitive and two structures from each family. We carried out reactive molecular dynamics simulations, using the ReaxFF force field as available in the LAMMPS code. Our results also show they exhibit remarkable resilience under mechanical compression. They can be reduced to half of their original size before structural failure (fracture) occurs.
INTRODUCTION Schwarzites are ordered 3D porous graphene-like nanostructures with stable negatively curved sp2-hybridized carbon atoms. These structures were proposed by Mackay and Terrones in 1991. They used the concept of negative curvature in the context of periodic graphitic structures, with the same shapes as triply periodic minimal surfaces (TPMS) [1]. They demonstrated that these structures were energetically stable and therefore possible to synthesize [2,3]. Recently, new porous carbon networks were synthesized [4] and there is a renewed interest in these kind of structures due to their interesting properties and many potential applications, such as energy absorbing materials [5,6]. In this work, we investigated the mechanical behavior under compressive strain of four different Schwarzites through reactive molecular dynamics (MD) simulations. We focused on two Schwarzites families (Gyroid and Primitive) and two structures in each family (see Figures 1-4). These chosen structures differ mainly through their local flatness and they are representative of the large Schwarzite families [1-3]. THEORY AND SIMULATION DETAILS
Downloaded from https://www.cambridge.org/core. Access paid by the UCSB Libraries, on 04 Mar 2018 at 06:04:07, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms. https://doi.org/10.1557/adv.2018.124
All MD simulations were carried out using the ReaxFF force field [7], as implemented in the open source code LAMMPS [8,9]. ReaxFF is used in simulations involving classical molecular dynamics but with the advantage of accurately describing chemical processes, such as formation and breaking of covalent bonds. Its parameterization is obtained using Density Functional Theory (DFT) calculations and its accuracy, compared with experimental data, i
Data Loading...
