Experience in registration of evaporation of liquid drops on a substrate by the capacitive method

Abstract

This paper presents the results of an experimental study of the dynamics of evaporation of nanofluid droplets based on distilled water with a mass concentration of SiO2 nanoparticles of 0.1%, 0.5%, and 7% lying on a metal surface. The drop height was changed over time using original equipment, which is based on an integrated approach to the combined use of capacitive and optical recording methods. The experimental results show that the change in the height of nanofluid droplets with concentrations of 0.1%, 0.5%, and 7% is linear over the main part of the evaporation time interval. A deviation from the linear law is observed at the final stage, at the time interval of complete evaporation. The time for complete evaporation of droplets of nanofluids with a concentration of 0.1% increases by 20%, for droplets with a concentration of 0.5%, it increased by 28% in comparison with the evaporation of droplets of the base liquid. The particle concentration of 7% does not lead to an increase in the evaporation time of droplets in comparison with the evaporation of low concentration droplets. Before the formation of a jelly-like residue of nanoparticles, the evaporation rate of droplets with a particle concentration of 7% is comparable to the evaporation rate of droplets with a concentration of 0.1%.

Drying of bio-colloidal sessile droplets: Advances, applications, and perspectives

“…(III) Illustration presenting the real-time AFM research strategy, adopted from [180]. (IV) Scheme of the capacitive method for studying drying droplets, adopted from [181]. (V) Schematic diagram of the microdroplet generation system with a humidity control module for induction time measurement via deliquescence-recrystallization cycling, adopted from [182].…”

“…In a different study, a simple capacitive method was employed to simultaneously record the height and shape of the droplet during the drying process in the form of a digital signal. This signal can be combined with the visual method to obtain a simultaneous digital image [181]. Similarly, the droplet's physical properties, such as viscosity, composition, surface tension, wettability, and inner structure dynamics, could be measured by the magnitude of AMI signal from a droplet drying on the surface of a quartz resonator oscillating with ultrasound frequency [142].…”