Growing drop instrument

As discussed by MacLeod Radke (1993) the growing drop instrument in the design shown in Fig. S.19 provides three experimental techniques a maximum drop pressure, a continuously... 

All drop and bubble methods are based on the Laplace equation of capillarity. In order to study dynamic aspects of adsorption, the growing drop or bubble and the expanded drop methods are suitable (3). In Figure 12.13, the schematic of a static or growing drop instrument is shown. In applications of capillary pressure tensiometry, an equation which is equivalent... 

The difference in the design of the other growing drop set-ups consists most of all in the use of a direct pressure transducer instead of a differential one. In all cases the data acquisition is made by an on-line coupled computer. In the instrument of Nagarajan Wasan (1993) the syringe is also controlled by the computer allowing different types of volume, and consequently drop surface area changes to be measured. The instruments of MacLeod Radke... 

Now commence the voltage sweep using a scan rate of 5 mV per second, or with a manual polarograph, increase the voltage in steps of 0.05 V. The recorder plot will take the form shown in Fig. 16.4 if a manual instrument is used, then since the current oscillates as mercury drops grow and then fall away, the plot will have a saw-tooth appearance, and for measurement purposes a smooth curve must be drawn through the midpoint of the peaks of the plot. 

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