FIG. 7 Isotherms of interface tension of aqueous EO10 solutions in contact with tetradecane (curve 1) and of the EO surfactant solution in tetradecane

The second method of treatment of experimental results is based on integration of Eq. (11) from l10 at τ=0 to l1 at a given time τ after expressing the flow rate as v=dl1/dτ:

vl1eτ=Cτ=(l1−l10){(η1/η2) [L−(l1+l10)/2]+(l1+l10)/2} =B(τ) (15)

At C=constant, the B values depend linearly on the time of displacement τ. This allows determination of the parameter C in Eq. (13) from the slope of the linear graph B(τ). For this purpose, a change in the position of the meniscus l1 during time at a constant pressure drop ∆P was measured. Results of the measurements may be transformed into a vl1e(∆P) function using the relation vl1e=B/τ and corresponding ∆P values.