We used the nonionic surfactant ethoxylated lauryl ether
(ULTROLs L70), obtained from Oxiteno-Brazil, with seven ethylene
oxide (EO) units in its chain, to prepare the oil-in-water
nanoemulsion. As the oil phase, we used Solbrax Eco 175/225.
This is a solvent produced by Petrobras and was donated by
its distribution subsidiary, BR Distribuidora, Brazil. It is mainly
composed of aliphatic and naphthenic hydrocarbons with a
distillation range between 175 and 225 1C.
The crude oil used came from Brazilian well and was donated
by the Petrobras Research Center. It had the following
characteristics:¼21.21 API; saturates content¼40.7%, aroma