Modeling and calculation of the process of rapid expansion of supercritical fluid yielding nanoparticles

New Approaches to the Modeling and Calculation of Supercritical Expansion and Micro- and Nanoparticle Formation

“…The model becomes much more complicated if the expansion of multicomponent fluid is accompanied by the formation of new phase. In our earlier studies, a number of simplifying assumptions were introduced, which generally complied with the physical principles of the process. The assumptions were as follows: (1) formation of new phase only in the subsonic expansion region, (2) 1D flow of a given expansion geometry (triangle expansion in the super- and subsonic flow regions), and (3) uniform distribution of the flow velocity, density, and pressure throughout the Mach disc.…”

“…A brief review presented in our earlier work concerning nucleation models (see also refs − ) accounting for, besides coagulation, continuous particle growth by condensation, i.e., transition of a solute from the gas phase into liquid (solid) particle.…”

“…The present work is an indirect continuation of previous studies of rapid expansion of supercritical solutions (RESS), condensation of a solute, and formation of solid particles. 1 In the latter work, the jet expansion was modeled in 1D approximation with preset shape of boundaries and shock waves. In the present work, the modeling is focused on the realistic jet expansion process.…”

“…In ref , we analyzed in detail the potentials, advantages, and shortcomings of existing methods to synthesize nanosized particles using supercritical fluids and explained the choice of the rapid expansion method. The problems related to particle formation by rapid expansion of supercritical solutions are thoroughly discussed in, for example, refs − .…”