Laboratory of Electroacoustic Studies of Electrolytes
The laboratory develops prototypes of resonance tensiometers and mechatronic systems for the precise control and analysis of microdroplets. It conducts experimental tensiometric and electroacoustic studies of surface tension, contact angles and resonant oscillations of liquid microdroplets.
Description of Activities
Description of Services
Study of microdroplets (liquid–gas interface)
Detailed description of the service: The study is carried out using a KRÜSS tensiometer. The following measurements are performed:
- pendant drop method – IFT, sessile drop – contact angle, sessile drop – SFE, captive bubble.
- Double sessile drop mode. Oscillating drop mode by volume variation. Electroacoustic studies. Resonance tensiometry. Determination of the surface tension of liquids. Determination of contact angle and wetting. Determination of the SFE of solid surfaces.
| Services offered | Price in EUR* |
| Measurement of the surface tension of liquids (SFT) at room temperature: study of liquids (liquid–gas interface) to determine surface tension by the pendant droplet method. | 76 |
| Measurement of the temperature dependence of the surface tension of liquids (SFT) in the temperature range from -5 to +80 ℃: study of liquids (liquid–gas interface) to determine surface tension by the pendant droplet method at equal temperatures of the liquid and the surrounding air. | 228 |
| Wetting, measurement of the contact angle of liquids: study of wetting on a solid surface at room temperature by measuring the contact angle of liquids at the solid–liquid–gas interface using the sessile droplet method. | 114 |
| Determination of the surface free energy of surfaces (SFE): measurement of the contact angle, at room temperature, of at least two reference liquids at the solid–liquid–gas interface and determination of the surface free energy (SFE) by the sessile droplet method. | 152 |
| Study of the viscoelastic properties of liquids: determination of the elastic and viscous moduli (E’ and E”) by the oscillating pendant drop method (oscillating drop measurement). | 114 |
| Data interpretation | 24 |
* The prices quoted are indicative and depend on the scope of the research. They include VAT at 20%.
Equipment
The KRÜSS tensiometer is a profile tensiometer – an instrument for analysing the profile of liquid drops. It enables precise measurement of the surface tension of pendant or sessile liquid drops by contour analysis. It measures the contact angle of liquid drops supported on a solid surface, as well as the corresponding surface free energy. A special optical cuvette and a circulating thermostat allow liquid drops to be studied in a controlled liquid or gaseous environment at temperatures from -10 to 130 °C. The instrument’s computer-controlled dosing system ensures precise control of the volume of the drops under study, while the software enables repeated automated measurements to be carried out according to predefined templates.
Contact
Head: Dr Nikolay Zografov, zoggy@phys.uni-sofia.bg
Access to the Laboratory and Service Requests
The laboratory is part of the research infrastructure of the National Centre of Excellence “Mechatronics and Clean Technologies” and is located on the Lozenets campus. Requests for access and for joint research are therefore processed centrally — see Contact. In addition, a full overview of the Centre’s other laboratories is available on the Infrastructure and Laboratories page.
The laboratory’s equipment was established under project BG16RFPR002-1.014-0006, funded under the Research, Innovation and Digitalisation for Smart Transformation Programme 2021–2027, co-funded by the European Union through the European Regional Development Fund.