Jump to main content
Jump to site search

Issue 42, 2016
Previous Article Next Article

Optovibrometry: tracking changes in the surface tension and viscosity of multicomponent droplets in real-time

Author affiliations

Abstract

An instrument was developed for measuring real time changes in the surface tension and viscosity of multicomponent droplets of miscible liquids and other soft materials. Droplets containing glycerol and water were supported on superamphiphobic surfaces and vibrated by applying a short mechanical impulse. Laser light was refracted through the droplets and allowed to fall on the surface of a photodiode. Time dependent variations in the intensity measured by the photodiode during vibration were used to monitor the decay of the droplet oscillations. The frequencies and spectral widths of the droplet vibrational resonances were then obtained from Fourier transforms of these time dependent intensity signals. A recently developed model of viscoelastic droplet vibration was used along with these values and measurements of the drop dimensions to extract the surface tension and viscosity of the drops as they evaporated. Collection of data was automated and values of frequency, spectral width, drop size, surface tension and viscosity were obtained with a time resolution of three seconds over a period of thirty minutes. The values of surface tension and viscosity obtained were shown to be in good agreement with literature values obtained from bulk glycerol/water solutions; thus validating the technique for wider application to other multicomponent liquids and soft matter systems.

Graphical abstract: Optovibrometry: tracking changes in the surface tension and viscosity of multicomponent droplets in real-time

Back to tab navigation

Supplementary files

Publication details

The article was received on 17 Aug 2016, accepted on 23 Sep 2016 and first published on 23 Sep 2016


Article type: Paper
DOI: 10.1039/C6SM01901C
Citation: Soft Matter, 2016,12, 8790-8797
  •   Request permissions

    Optovibrometry: tracking changes in the surface tension and viscosity of multicomponent droplets in real-time

    V. C. Harrold and J. S. Sharp, Soft Matter, 2016, 12, 8790
    DOI: 10.1039/C6SM01901C

Search articles by author

Spotlight

Advertisements