Radiophysical methods in the study of physicochemical properties of liquids

Abstract

Relevance: The creation of new express methods for the qualitative and quantitative analysis of solutions and suspensions and biological liquids, as well as the development of technical means for their implementation, are urgent tasks in various fields of science and technology, in particular, in biotechnology and biomedicine. Also, the relevance of the work is due to the need to optimize technological processes for the production and synthesis of nanomaterials. The purpose of the work is to verify theoretically and experimentally the possibility of using radiophysical methods to assess the physicochemical parameters of solutions and suspensions. Another purposes are optimization of the technological process of laser ablation and solution of the physicochemical problem of the synthesis of iron nanoparticles in magnetite shells. Materials and methods: The paper presents a comparative analysis of methods for calculating the effective parameters of the system dielectric – metal inclusions using the mixing formulas of Maxwell–Garnett, Bruggeman and the finite element method. It is shown that in the case of metallic inclusions, the Bruggeman formula gives a more adequate result, which is consistent with the experimental results. The analysis of aqueous suspensions of metal nanoparticles was carried out by the method of impedance spectroscopy. Results: A simple method has been developed for the synthesis of iron nanoparticles with a magnetite shell based on the reaction of controlled oxidation of iron nanoparticles by ozone. A microscopic analysis of the obtained particles was carried out and the rate of formation of the magnetic shell was determined. The method of impedance spectroscopy for measuring the concentration of metal nanoparticles in the process of laser ablation has been tested. It is shown that the state of sedimentation equilibrium of the suspension corresponds to a specific value of electrical conductivity. Conclusion: It is shown that the method of impedance spectroscopy can be used as an indirect method for assessing the qualitative and quantitative physicochemical parameters of solutions and suspensions. The simulation of the influence of the distribution of metal particles in a dielectric matrix on the electrophysical parameters of the suspension is carried out.