Effect of chain rigidity on morphological transformation and adsorption behaviors of biocompatible polyoxyethylene-based surfactants at water–air surface

Novel biocompatible acrylpimaric acid– and polyoxyethylene-based surfactant was prepared in our laboratory. Moreover, the influence of chain rigidity on the morphological transformation and adsorption behaviors of polyoxyethylene acrylpimaric acid copolymer and marketed polyethylene-polypropylene glycol (F188) surfactants was evaluated. The adsorption behaviors including critical micelle concentration (CMC), morphological change, and adsorption capacity were investigated. Reorientation theory was put forward to depict the adsorption and the morphological transformation for these two kinds of polyoxyethylene-based surfactants at water and air surface. The solvent molar fraction decreased and that of surfactant molecules increased as polyester concentration increased. The amounts of state 1 and state 2 surfactants adsorbing on the surface were calculated. The free energy of adsorption is far less than the energy of micellar formation. The consequences are helpful to illustrate the chain rigidity effect on adsorption behaviors and to expand in the formulation of micelles.