P. Moravec

Trapping of impurity molecules in condensation from mixtures of gases

The problems of trapping of impurity molecules in deposition of substance from a mixture of gases are investigated. Both internal and external problems are considered. The influence of the condensation rate of basic substance on the concentration of impurity molecules in a condensed phase is analyzed.

Effect of electromagnetic fields on transfer processes in heterogeneous systems

Some effects are analyzed which are related to the influence of electromagnetic radiation on transfer processes in heterogeneous systems. The influence exerted by the excitation of internal degrees of freedom of molecules in a field of the resonance laser radiation is considered, as well as the effect of volumetric heating of a porous catalyst particle in the field of microwave radiation. It is shown that on exposure to microwave radiation heterogeneous reaction in a particle of the porous catalyst can occur more uniformly over the particle volume. An expression is found for temperature distribution in a spherical particle of the porous catalyst resulting in a uniform course of chemical reaction over the particle volume.

Growth and evaporation of aerosol particles in the presence of adsorbable gases

Abstract Influence of adsorption of noncondensable molecules on the surface of phase transition on the rate of growth (evaporation) of aerosol particles (drops) is investigated theoretically. Combined manifestation of the effects that influence the rate of the growth of particles in the opposite directions is considered: decrease in surface tension on adsorption of a foreign gas and blocking of the surface of phase transition by the molecules adsorbed. The effect of the adsorption of the molecules of a noncondensable (in particular, buffer) gas on the rate of homogeneous nucleation and also on the growth of particles in chemical deposition is discussed.

Lead and/or Lead Oxide Nanoparticle Generation for Inhalation Experiments

A method of the continual generation of lead or lead oxide nanoparticles for potential subsequent inhalation experiments with laboratory animals was investigated. We examined the thermal decomposition and oxidation of lead bis(2,2,6,6-tetramethyl-3,5-heptanedionate) in an externally heated tube reactor as well as the evaporation and condensation of metallic lead. The particle production dependence on experimental conditions was investigated using a scanning mobility particle sizer (SMPS), and the particle characteristics were studied using transmission electron microscopy (TEM), high-resolution TEM (HRTEM), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), atomic absorption spectroscopy (AAS), elemental and organic carbon analysis (EC/OC), X-ray photoelectron spectrometry (XPS), and X-ray diffraction (XRD) methods. The evaporation/condensation was evaluated as being the most suitable for inhalation experiments due to its simplicity, high production rate, and the well-defined composition of the nanoparticles. Copyright 2015 American Association for Aerosol Research

Influence of surface phenomena on the growth of aerosol particles in a buffer (admixture) gas

The influence of a buffer (admixture) gas on the deposition of molecules of a vapor on particles of an aerosol system is investigated.

Nano-sized particles from the CO2 laser assisted decomposition of tetraethylorthosilicate vapour

Abstracts are not published in this journal

Trapping of molecules by aerosol particles in physical and chemical deposition

The problem of the molecule trapping by aerosol particle is considered both for condensation growth of the particle and for heterogeneous chemical reaction on the particle surface. The equations for resultant flux of molecules into the particle and for the trapping coefficient are obtained. The temperature dependence of the trapping coefficient in the cases of the physical and chemical deposition is discussed.

Chemical Deposition on Aerosol Particles

Problems on the growth of aerosol particles in chemical deposition with allowance for the influence of a buffer (impurity) gas have been investigated theoretically.