Abstract
The surface activity of newly nonionic hydroxyl mixed ether surfactants HME
at air/water and solid/water interfaces was studied as a function of ethoxylation degree (n-value). The characteristics of this series of nonionic surfactant, including surface tension, critical micelle concentration cmc, adsorption onto hydrophilic saponite clay and hydrophobic Teflon are reported. The surface tension results indicate that cmc, surface tension after γ
, and the minimum surface area per adsorbed HME-surfactant molecule A
are all increased with n-value. Results of static light scattering are in agreements with those obtained using surface tension method. For HME-surfactants, strong adsorption measured by surface tension onto the hydrophilic synthetic clay mineral saponite. This result was also observed by atomic force microscopy AFM for HME
onto hydrophilic mica surface. On the other hand, the adsorption of HME-surfactant onto hydrophobic polytetraflouroethylene PTFE (Teflon) is less than that measured onto saponite. However, the adsorption at both surfaces has the same dependency on n-value.