Effect of Oxyethylene Groups on Adsorption Properties of Fatty Alcohol Polyoxyethylene Ether Sodium Sulfate with Narrow Ethylene Oxide Distribution.

The effect of oxyethylene groups on the adsorption properties of fatty alcohol polyoxyethylene ether sodium sulfate with narrow ethylene oxide distribution (AEmS, m = 3, 5, 7, 9) was characterized by means of the equilibrium surface tension, the dynamic surface tension and the contact angle. The results show that at a concentration lower than the critical micelle concentration (CMC) the oxyethylene groups act like hydrophobic groups to change the absorption properties. If the concentration is higher than the critical micelle concentration, the oxyethylene groups act as hydrophilic groups to change the absorption properties. The long polyoxyethylene chain of AE9S is very curly, which means that AE9S does not strictly follow the rule derived from AEmS (m = 3, 5, 7). The adsorption process of AEmS is a mixed diffusion-kinetic adsorption mechanism. [ABSTRACT FROM AUTHOR]