Silica nanoparticles

This work discusses the determination of mechanical properties of amorphous silica, and preparation of nanoparticles using Molecular Dynamics (MD) simulations. To this end, amorphous silica was generated from α-quartz crystalline structure using a melt-and-quench procedure. The mechanical properties of the amorphous silica were determined by using six virtual tests to obtain the material’s apparent elasticity tensor. The elastic moduli were then identified from the apparent tensor by using an isotropic projection. Mechanical testing showed that the amorphous silica exhibited strongly isotropic behavior, with high stiffness (bulk modulus of 36.84 GPa, shear modulus of 30.49 GPa, Young’s modulus of 71.69 GPa and Poisson’s ratio of 0.18). The results were compared with those reported in the literature, showing that our MD simulation yielded a good approximation of the behavior of amorphous silica. In addition, a preparation of nanoparticles was introduced to creating three nanoparticles of radii R_p = 1.5, 3, and 4.8 nm, respectively. Results showed that the nanoparticles presented a certain surface roughness, which increased when the size of the nanofiller decreased. The nanoparticles prepared in this study could be mixed into a polymer matrix in order to investigate local structural characteristics and the macroscopic behavior of the nano-reinforced materials.

For further details, please refer to the following publication:

Le, T. T.; Guilleminot, J.; Soize, C. Stochastic Continuum Modeling of Random Interphases from Atomistic Simulations. Application to a Polymer Nanocomposite. Computer Methods in Applied Mechanics and Engineering 2016, 303, 430–449. Link