Pulsating bubble method

Schematic of a pulsating bubble method according to Lunkenheimer Kretzschmar (1975) and Wantke et al. (1980)...

Table 1.5 reviews the capabilities of the most common (quasi-)static methods (we excluded the very fast oscillating jet and pulsating bubble), obtaining dynamic information. Some of these are intrinsically dynamic in that the measurement requires the extension of an interface (drop weight, maximum bubble pressure), so that y(t) data can in principle be obtained when the rate of extension can be varied in a controlled fashion. Others are basically static (shapes of sessile or pendent drops and bubbles), but can be rendered dynamic by disequilibratlon. 

However, the use of air bubbles has some disadvantages. Thus, their high compressibility results in pulsation their injection and subsequent removal complicates the operational design and their presence reduces the efficiency of separation techniques, e.g. dialysis, liquid—liquid extraction, hinders the implementation of stopped-flow methods and precludes miniaturization in many cases. 

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