Small molecule adsorption on to polyester capillary-channeled polymer fibers: Frontal analysis of naphthalene and naphthol (naphthalene and naphthol adsorption on capillary-channeled polymer fibers)

摘要

Frontal analysis was carried out employing polyethylene-terephthalate) capillary-channeled polymer fibers as the stationary phase for the immobilization of low-molecular-weight polycyclic aromatic hydrocarbon compounds (naphthol and naphthalene) from 2% methanol/water solutions. The effects of several experimental parameters on the frontal profile, the breakthrough volume, and the equilibrium parameters were determined for each solute. The amount adsorbed at exhaustion of naphthalene and naphthol was also compared. The kinetics and thermodynamics were maintained at relatively fast flow rates/linear velocities (similar to 6-18 mm/s). Comparisons of dynamic capacity revealed that naphthalene was more retained than naphthol, in most situations more than five times that of the naphthol adsorption. This increase in capacity is most likely due to the multilayering of naphthalene on the surface of the fibers through pi-pi interactions between the solute and the fiber surface and successive layering of solute molecules. The extent of layering is a function of the flow, with faster flow rates (and subsequent shear forces) reducing the extent of adsorbate-adsorbate interactions. Although the overall loading capacity of the capillary-channeled polymer fibers is far below porous phases, there are a number of attractive attributes that support further development.