Fuel, Vol.78, No.3, 309-317, 1999
Dynamic interfacial tension measurement of heavy crude oil-alkaline systems - The role of the counterion in the aqueous phase
The dynamic behaviour of the interfacial tension at the oil-water interface gamma((t)) for oleic acid and a 90% v/v Cerro Ne,oro-xylene solution had been studied under alkaline conditions. For the system oleic acid in paraffin, aqueous sodium carbonate with or without added sodium chloride, the usual gamma((t)) behaviour was observed, i.e, gamma drops to low or ultralow values at short times, remains low during a short period, and then rises to high( > 1 N m(-1)) values. However, when alkyl amines (ethyl, diethyl and triethyl amine) were used as alkalis in the aqueous phase, gamma((t)) first dropped to a relatively high value (1.5