Dispersion properties of triply periodic minimal surface stationary phases for LC: The case of superficial adsorption

The exact moment method for the determination of the dispersion tensor in retentive porous media has been adopted to compute the dispersion coefficients, the plate height curves and the kinetic performance factors of eight different 3D printable stationary phases based on triply periodic minimal surfaces (TPMS). The two cases in which the stationary phase is impermeable (hydrodynamic dispersion) or superficially retentive have been analyzed in detail. The Carman–Kozeny relationship between permeability $K_v$, hydraulic diameter $d_h$ and hydrodynamic tortuosity $\tau$ holds true for all the geometries investigated with a unique shape coefficient $K_0$. The analysis of plate height curves indicates that best performing geometries are associated with lower values of the effective diameter $d_{\mathrm{eff}}$, and thus lower values of permeability. When compared in terms of kinetic performance factor, the best performing geometries are those characterized by lower tortuosity and higher coefficient of uniformity $\delta$ of the axial velocity field. Among all the geometries investigated, sheet-based Gyroid and Primitive are the best performing, both in terms of maximum kinetic performance factor $e_{c,max}\in (1,1.4)$ and in terms of column void time $t_0\in (0.4s,1.6s)$ for $\Delta P=500$ bar.