Kinetics of the Colloidal System of Stabilized Boron Nitride in the Aqueous Subphase

Abstract

Purpose. Preparation of a colloidal solution stabilized with stearic acid of hexagonal boron nitride nanoparticles, analysis and visualization of structure formation and its spatial characteristics, creation and study of floating monolayers on the water surface.Methods. The determination of the chemical structure was carried out using IR spectroscopy; modeling of the crystal structure and processes of colloidal solution synthesis was carried out using the Materials Studio 2020 software package with CASTEP, Forsite, Blends Calculation and Dmol3 modules; study of the formation of a monolayer on a setup for the formation and study of monolayers by the Langmuir-Blodgett method KSV Nima 2002, equipped with a Wilhelmy balance, Brewster microscopy and thermal stabilization.Results. A colloidal system of hexagonal boron nitride nanoparticles stabilized with stearic acid has been synthesized. The absence of chemical reactions and molecular deformations of stearic acid in the dispersed medium of a colloidal system (chloroform), as well as deformations of crystalline and molecular structures during passivation of stearic acid molecules on the surface of hexagonal boron nitride nanoparticles are shown using first-principles modeling. IR spectroscopy methods have established the complete evaporation of the dispersion medium and the fact of stable stabilization of nanoparticles. The obtained IR spectroscopy results are in good agreement with ab-initio modeling data showing the attachment of stearic acid molecules to the surface of hexagonal boron nitride nanoparticles by polar groups containing oxygen atoms, since in this case the minimum energy value of this system is achieved.Conclusion. The paper shows the possibility of stable stabilization of hexagonal boron nitride nanoparticles by stearic acid molecules and subsequent creation of a monolayer from them for deposition of defect-free thin films by the Langmuir-Blodgett method with demanded mechanical, electrical, optical and thermal properties.