Wettability of Aqueous Solutions of Eco-Friendly Surfactants (Ethoxylated Alcohols and Polyoxyethylene Glycerin Esters)

Wettability of aqueous solutions of ethoxylated alcohols (EA), polyoxyethylene glycerin esters (PGE) and mixtures of them have been studied. For the EA assayed, the best wettability is reached when the EA have the lowest alkyl chain length and the lowest number of ethylene oxide units in the molecule. The best wettability for the PGE assayed is reached when the number of ethylene oxide units in the molecule is lowest. Aqueous solutions of these mixtures show a wetting power between those of the pure surfactants. The wettability of PGE can be improved by adding EA with a low alkyl chain length and a low number of ethylene oxide units. An exception and synergistic effect has been detected for aqueous solutions of EA (with alkyl chain length 12–14, number of ethylene oxide units 11) and PGE (with a number of ethylene oxide units equal to 2). These mixtures have better wettability than the surfactants separately, so that it might be advantageous to use both surfactants together.