Amphipathic polymers with stimuli-responsive microdomains for water remediation: Binding studies withp-cresol

Amphipathic, stimuli-responsive water-soluble polymers have been investigated as potential remediation agents for micellar enhanced ultrafiltration (MEUF). The systems represent divergent architectural types, a triblock ABA copolymer of PEO-PPO-PEO, an n-octylamide modified poly(sodium maleate-alt-ethyl vinyl ether), and the transport protein, bovine serum albumin. Each type exhibits stimuli-dependent microphase separation or domain formation in response to temperature, pH, and/or ionic strength changes. Segmental associations result in hydrophobic clusters resembling those present in small molecule surfactant micelles. The effects of such segmental aggregation on sequestration of a model hydrophobic foulant, p-cresol, have been investigated using equilibrium dialysis. The favorable molar binding values, the large hydrodynamic dimensions of the stable polymer aggregates, and potential reversibility of foulant loading could have commercial utility in high flow rate, multiple-pass remediation processes.