(78a) Surfactant-Polymer Association in Aqueous Solutions

Mixtures of surfactants and polymers afford great flexibility in conferring structure and function in waterborne formulations applied to coatings, home and personal care products, food and drinks, pharmaceutics, and enhanced oil recovery. [Tsianou & Alexandridis, Surfactant Sci. Ser. 2005, 124, 657-708] [Bodratti et al., Adv. Colloid Interface Sci. 2017, 244, 132-163; DOI: 10.1016/j.cis.2016.09.003] [Bodratti & Alexandridis, Expert Opin. Drug Deliv. 2018, 15 (11), 1085-1104; DOI: 10.1080/17425247.2018.1529756] Underlying such structure and function are inter- and intra-molecular interactions that depend on the (i) polymer chemistry, architecture and concentration, (ii) surfactant type and concentration, (iii) solvent conditions (e.g., pH, ionic strength, presence of cosolvents or cosolutes), (iv) interfaces and surfaces (e.g., presence of colloidal particles), and (v) external stimuli (e.g., temperature, shear). [Tsianou & Alexandridis, Langmuir 1999, 15 (23), 8105-8112; DOI: 10.1021/la990701d] [Chronakis & Alexandridis, Macromolecules 2001, 34 (14), 5005-5018; DOI: 10.1021/ma000609k] [Fajalia & Tsianou, J. Phys. Chem. B 2014, 118 (36), 10725-10739; DOI: 10.1021/jp5023168] The presentation will highlight examples from our research on the formation and structure of complexes by commercially available anionic surfactants and nonionic poly(ethylene oxide)-based polymers in water, as affected by the ability of the polymer to associate upon incorporation of hydrophobic poly(propylene oxide) segments, the hydrophobicity of the surfactant (aliphatic hydrocarbon vs fluorocarbon chain), and the hydrophobicity of the solvent (added ethanol, salt or ionic liquids).