Ultrasonic vibration potential

The colloid vibration potential (difference) E or CVP is the a.c. potential difference measured between two Identical relaxed electrodes, placed in the dispersion if the latter Is subjected to an (ultra)sonlc field. CVP Is a particular case of the more general phenomenon, ultrasonic vibration potential (UVP), applying to any system, whether or not colloids are present. This field sets the particles into a vibrating motion, as a result of which the centres of particle charge and countercharge are periodically displaced with respect to each other. This phenomenon is the a.c. equivalent of that observed in the Dorn effect. Counterpart to this is the electrokinetic sonic amplitude, ESA, the amplitude of the (ultra)sonlc field created by an a.c, electric field in a dispersion. 

Use of Ultrasonic Vibration Potential To Monitor Coalescence. The complex chemical nature of crude oils makes it difficult to relate the dispersion behavior to the physicochemical properties at the crude-oil-water interface. In addition, the nonpolar and nontransparent nature of the oleic phase provides significant obstacles for studies of the interactions of the suspended water droplets in real systems. Recent development (28, 29) of electroacoustical techniques has shown considerable promise for electrokinetic measurements of colloidal systems and the direct monitoring of the rate and extent of coagulation (flocculation and coalescence) of water droplets in nontransparent water-in-oil media. The electroacoustic measurement for colloidal systems in nonpolar media is based on the ultrasound vibration potential (UVP) mode, which involves the applica-... 

Ozawa, M. and Hattori, M.. Ultrasonic vibration potential and point of zero charge of some rare earth oxides in water, 7. Alloys Compounds, 408/412, 560, 2006. 

The kinetic potential is usually denoted as the zeta (0 potential and it is determined from the electrophoretic mobility of the extremely dilute particles in an electric field. More recently, the nse of electrokinetic sonic amplitude (ESA), acoustosizer (AZR), or colloid (or ultrasonic) vibration potential (CVP) has become available for the determination of the potential in rather concentrated particle suspensions. Again the potential may be measured as a function of either the metal concentration or the pH. In the latter case the point where the mobility ceases is denoted the isoelectric point (pH,Ep Fignre 8.27). It correlates particnlarly well with the stability of the sol. 

Ultrasonic vibration potential (UVP), an electro-acoustical method involving detection of the alternating electric field (potential or current) generated when dispersed species are made to move by imposed sound waves (Figure 4.8). This technique is also referred to as colloid vibration potential (CVP) or colloid vibration current (CVC). 

R Zana, E Yeager. Ultrasonic Vibration Potentials. In J O M Bockris, BE Conway, eds. Modem Aspects of Electrochem. Plenum, New York 14 1—61, 1982. 

Zana and Yeager (1966) measured the individual or absolute ionic partial molar volumes of ions at room temperature using the ultrasonic vibration potentials and they could assign values for the V° of some ions with an error of 2 cm moT, while the uncertainty was higher for others. Thus, for at 22°C they found Vh+ = -5.4 cm mol". ... 

Figure 5.17 Principle of acoustophorcsis. Concerning the UVP (Ultrasonic Vibration Potential - top), an ultrasonic wave applied on a liquid (transducer) induces solvent motion. As the two charged species have a different masses and frictional coefficients, its move differently. The charge heterogeneonsness which appeared in this way generate a macrr opic and thus measurable electric field (electrodes). Concerning the ESA (Electro Sonic Amplitude - bottom), an alternative electric field is applied (electrodes). Eachs ion species moves in opposite direction. This motion induces a detectable ultrasonic wave (transducer).

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