Polymerizable Deep Eutectic Solvent-Based High Internal Phase Emulsion Templates for Fabricating Porous Poly(Acrylic Acid)

Fabrication of hydrophilic porous polymer materials via high internal phase emulsion (HIPE) templating is highly attractive. In this work, a newly developed approach is presented for the fabrication of porous poly(acrylic acid (AA)) (PAA) monoliths. A series of polymerizable deep eutectic solvents (PDES), based on choline chloride (ChCl) and AA, are synthesized and validated through molecular dynamics simulations. Tetradecane-in-PDES HIPEs with varying ChCl and AA compositions are stabilized using Pluronic F68, followed by radical polymerization in the presence of a cross-linker and initiator to produce macroporous PAA-based polyHIPEs. The resulting polyHIPEs exhibit a highly porous structure with adjustable pore size and interconnectivity, influenced by PDES composition, surfactant concentration, and internal phase volume fraction. In contrast, polyHIPEs prepared from oil-in-water HIPE display a larger pore structure but lower interconnectivity. Furthermore, PDES composition-dependent pH-responsive swelling behavior and mechanical properties are observed, highlighting the potential of these materials for a range of applications.