Hydrogen Bonding Strength Determines Water Diffusivity in Polymer Ionogels.

摘要: Polymeric ionogels, cross-linked gels swollen by ionic liquids (ILs), are useful vehicles for the release and storage of molecular solutes in separation, delivery, other applications. Although rapid solute diffusion is often critical performance, it remains challenging to predict diffusivities across multidimensional composition spaces. Recently, we showed that water (a neutral solute) diffuses through alkyl-methylimidazolium halide ILs hopping between hydrogen bonding sites on relatively immobile cations. Here, expand this activated mechanism two significant ways. First, demonstrate poly(ethylene glycol)diacrylate ionogels via same at a reduced rate. Second, hypothesize activation energy barrier can be determined from simple 1H NMR chemical shift measurements proton responsible H-bonding. This relationship enables water's diffusivity class predicted quantitatively, requiring only (1) composition-dependent Arrhenius behavior single IL (2) spectra interest. High-throughput microfluidic Fabry-Perot interferometry verify prediction accuracy broad formulation space (four ILs, 0 ≤ xH2O 0.7, ϕPEGDA 0.66). The predictive model may expedite IL-material screening; moreover, intimates powerful connection mobility suggests targets rational design.