A computational study of the size effect of SiO₂ spherical nanoparticles in water solvent

Context: This study comprehensively describes the interaction between SiO₂ spherical nanoparticles and water molecules as a solvent medium. Our goal is to provide valuable insights into the significance of nanoparticle size in understanding their behavior and the resulting changes in the physical properties of materials. Our results indicate that SiO₂ nanoparticles exhibit a strong affinity for water, which increases with the nanoparticle size. Our investigation can be relevant for the design of new composite materials with applications ranging from medical prostheses to quantum electronics, optoelectronic devices, catalysis, and photoluminescence. We have concentrated on the study of the amorphous, where size effects seem to be more pronounced. Methods: A computational study was carried out within the molecular dynamics simulations framework available in the GROMACS-v2019.2 software, with force fields consistent with DFT and the CHARMM36 utilized in the molecular description of the systems. The water model used was the TIP3P implemented in CHARMM36 force fields. A comprehensive analysis of molecular interactions of various system configurations was performed, including radial distribution function (RDF), mean square displacement (RMSD), hydrogen bonding analysis, interfacial analysis, and studying system size's effect on mechanical properties.