(648d) Surfmer-Guided Design for Fabrication of Functional Polyhipes for Water Remediation

Polymerized high internal phase emulsions (polyHIPEs) are an emerging class of porous polymers known for their high porosity, low density, and tunable pore structure, making them attractive for water treatment applications. However, conventional fabrication methods rely on non-reactive surfactants that get washed out post-polymerization, posing threat of secondary contamination and material instability. This work focuses on developing polymerizable surfactants also known as surfmers which will covalently bind onto the polyHIPE framework as a solution to this challenge. Poly(ethylene)glycol, (PEG)-fatty acid-based surfmers were synthesized by incorporating polymerizable methacrylate end-groups onto the hydrophilic PEG-fatty acid backbones. Preliminary synthesis and interfacial studies of non-polymerizable PEG-based monoester surfactant analogs revealed clear structure – property trends in interfacial tension behavior between 10% acrylic acid aqueous solution and n-hexadecane, simulating the expected conditions during HIPE formulation. These results provided insights into how PEG chain length and fatty acid tail structure affect interfacial activity and emulsion stability, which in turn informed selection and optimization of surfmer candidates for stable HIPE formation. Based on these findings, polyHIPEs were fabricated with tailored morphological and mechanical properties. Emulsion parameters such as surfmer concentration, continuous phase monomeric concentration, mixing rate were tuned to control droplet formation, pore structure of resulting polyHIPEs as these are directly related to final adsorption performance. The presented work will demonstrate the clear relationship between the IFT structure property relationships of the surfmers and the resulting pore structure and morphology as well as the adsorption behavior of a model pollutant. This study not only aims to produce a structurally sound, surfmer-informed route for fabricating functional polyHIPEs optimized for selective pollutant capture. It also provides a foundation for how small molecular design changes in surfmers can be leveraged to guide macrostructural outcomes of resulting polyHIPEs.