Oszillating Drop and Bubble Analyzer ODBA1M
The use of small spherical drops allows oscillation at much higher frequencies as it is accessible with the PAT technique. This is true due to decreased impact of inertia on the drop oscillation modes, which are expected to oscillate in a more or less radial way. As soon as additional (wobbling) modes come into play, the limits of this technique are reached. Unfortunately, there is not a single control parameter available as in PAT measurements to test the physically reasonable frequency limit. Only a general trend can be clearly seen: the smaller the drop and the smaller the amplitudes of oscillation are, the higher are the frequencies for physically reasonable experiments. A real test of this frequency limit would require experiments with liquid systems in absence of any surface active molecules, including possible impurities in the studied liquids.
This instrument is designed as an additional module for the PAT1, PAT1M and PAT2S, using the temperature control chamber, optical bench, light source and video image acquisition for the alighnment, focusing and determination of the drop size. If drops have a spherical shape (very small and/or low density), the measurement of the pressure P together with the radius of curvature r yields the interfacial tension y.
For measurements of interfacial tensions between a liquid and a fluid, the density difference is needed. Calibration against the external and hydrostatic pressure is needed as well.
For drop/bubble oscillation experiments only pressure changes have to be measured along with the phase shift to the generated area oscillation.
For measurements of interfacial tensions between a liquid and a fluid, the density difference is needed. Calibration against the external and hydrostatic pressure is needed as well.
For drop/bubble oscillation experiments only pressure changes have to be measured along with the phase shift to the generated area oscillation.
Features of the instrument
drop oscillation at frequencies from 1 to 100 Hz to determine the dilational elasticity and viscosity of interfacial layersapplicable to bubbles and drops (also immersed in a second liquid)easy temperature controlmeasurement of interfacial tension between two liquids of same density (see also DPA-1)dynamic interfacial tensions for adsorption times between 50 ms and hours
Reference List
Reference list for Capillary Pressure Tensiometer DPA1 and ODBA1
E.K. Zholkovskij, V.I. Kovalchuk, V.B. Fainerman, G. Loglio, J. Krägel, R. Miller, S.A. Zholob and S.S. Dukhin, Resonance behaviour of oscillating bubbles, J. Colloid Interface Sci., 224(2000)47-55
R. Miller, V.B. Fainerman and V.I. Kovalchuk, Bubble and Drop Pressure Tensiometry, in “Encyclopaedia of Surface and Colloid Science”, A. Hubbard (Ed.), Marcel Dekker, New York, 2002, 814-828, ISBN 0-8247-0633-1
V.I. Kovalchuk, E.K. Zholkovskij, J. Krägel, R. Miller, V.B. Fainerman, R. Wüstneck, G. Loglio and S.S. Dukhin, Bubble oscillations in a closed cell, J. Colloid Interface Sci. 224(2000)245 – 254
V.I. Kovalchuk, J. Krägel, R. Miller, V.B. Fainerman, N.M. Kovalchuk, E.K. Zholkovskij, R. Wüstneck, and S.S. Dukhin, Effect of the non-stationary viscous flow in the capillary on oscillating bubble and oscillating drop measurements, J. Colloid Interface Sci., 232(2000) 25- 32
R. Miller, V.B. Fainerman and V.I. Kovalchuk, Bubble and Drop Pressure Tensiometry, in “Encyclopaedia of Surface and Colloid Science”, A. Hubbard (Ed.), Marcel Dekker, New York, 2002, 814-828, ISBN 0-8247-0633-1
V.I. Kovalchuk, J. Krägel, A.V. Makievski, G. Loglio, F. Ravera, L. Liggieri and R. Miller, Frequency characteristics of amplitude and phase of oscillating bubble systems in a closed measuring cell, J. Colloid Interface Sci., 252 (2002) 433-442
E.K. Zholkovskij, V.I. Kovalchuk, V.B. Fainerman, G. Loglio, J. Krägel, R. Miller, S.A. Zholob and S.S. Dukhin, Resonance behaviour of oscillating bubbles, J. Colloid Interface Sci., 224(2000)47-55
R. Miller, V.B. Fainerman and V.I. Kovalchuk, Bubble and Drop Pressure Tensiometry, in “Encyclopaedia of Surface and Colloid Science”, A. Hubbard (Ed.), Marcel Dekker, New York, 2002, 814-828, ISBN 0-8247-0633-1
V.I. Kovalchuk, E.K. Zholkovskij, J. Krägel, R. Miller, V.B. Fainerman, R. Wüstneck, G. Loglio and S.S. Dukhin, Bubble oscillations in a closed cell, J. Colloid Interface Sci. 224(2000)245 – 254
V.I. Kovalchuk, J. Krägel, R. Miller, V.B. Fainerman, N.M. Kovalchuk, E.K. Zholkovskij, R. Wüstneck, and S.S. Dukhin, Effect of the non-stationary viscous flow in the capillary on oscillating bubble and oscillating drop measurements, J. Colloid Interface Sci., 232(2000) 25- 32
R. Miller, V.B. Fainerman and V.I. Kovalchuk, Bubble and Drop Pressure Tensiometry, in “Encyclopaedia of Surface and Colloid Science”, A. Hubbard (Ed.), Marcel Dekker, New York, 2002, 814-828, ISBN 0-8247-0633-1
V.I. Kovalchuk, J. Krägel, A.V. Makievski, G. Loglio, F. Ravera, L. Liggieri and R. Miller, Frequency characteristics of amplitude and phase of oscillating bubble systems in a closed measuring cell, J. Colloid Interface Sci., 252 (2002) 433-442