Molecular Dynamics Simulation of Silica Oligomerization - Archive ouverte HAL
Communication Dans Un Congrès Année : 2018

Molecular Dynamics Simulation of Silica Oligomerization

Résumé

Silica is a mineral applied in many fields of everyday life, for instance as a reinforcement filler for the tires or an animal feed additive. Thus, full understanding of the process of its production is of great interest not only to scientists but also to the industry. The important part of the research on silica precipitation is analyzing the influence of experimental conditions on the final product morphology. Amorphous silica is a product of precipitation by neutralization of basic solution of sodium silicate with sulphuric acid. Its synthesis consists of few principal stages: mixing of the reactants, nucleation of silica, growth and agglomeration. Most of the studies found in the literature give insight into the final stages - aggregation and agglomeration of already formed silica clusters. At the same time, although, the events occurring at the beginning of precipitation are crucial for the following steps, they are not yet fully discovered. The problem lies in the nanometric size scale of the nucleating systems that is on the limit of detection of experimental methods with most of the processes appearing below it. Bearing in mind limitations of experimental techniques, another tool is required to complement and confirm obtained results. Hence, computer simulations are applied to act as a bridge between the nanometric time and length scales of nucleation and the macroscopic scales of the laboratory. Having a good understanding of the effect of operating parameters on the final product depends upon studying nucleation kinetics, mechanisms and clusters’ morphology. As a result, what a considered simulation method should provide, is not only the access to the time and size scale of nucleation but also to the details such as morphology of the clusters during oligomerization. The choice of a method satisfying all the aforementioned conditions is a difficult task. Nevertheless, it was stated that Molecular Dynamics (MD) simulation can provide at least partial information about the temporal evolution of the system of interest, as well as kinetics and mechanisms concerned. The purpose of this study is to bring better understanding to the initial stages of silicic acid oligomerization to serve as a starting point in the investigation on silica nucleation. In the series of simulations, using ReaxFF reactive force field, the effect of the initial sodium silicate concentration and pH on the distribution of species with time was studied. The obtained results were compared with the literature data.
Fichier non déposé

Dates et versions

hal-02197675 , version 1 (30-07-2019)

Identifiants

  • HAL Id : hal-02197675 , version 1

Citer

Malgorzata Kaminska, Frédéric Gruy, Jules Valente. Molecular Dynamics Simulation of Silica Oligomerization. The 2nd International Symposium on Computational Particle Technology, Monash University; Xi’an Jiaotong University; CSIRO, Dec 2018, Melbourne, Australia. ⟨hal-02197675⟩

Collections

CNRS
110 Consultations
0 Téléchargements

Partager

More