| Abstract: | The adsorption process between porous resins with different surface properties and nonylphenol non-ionic surfactants of the same hydrocarbon chain length but varying oxyethylene units was investigated. The adsorption of NPEOn with shorter EO chains is greater than those with longer EO chains on the surfaces of resins, and the strength of the adsorption was affected by resin surface-surfactant and surfactant-surfactant lateral interactions. Lateral interactions are endothermic, and contribute more to the adsorption process on aminated resins (MN-100, MN-150) than on hyper-crosslinked resins (MN-200, NDA-150). The surface interactions are mainly due to bonding between the hydrophobic moiety of the surfactant and hydrophobic surfaces of the resins without electrical interaction or hydrogen bonding, even on aminated resins (MN-100, MN-150). Positive ΔH values indicate that the adsorption process is endothermic overall, which is supported by the increase in adsorption capacity observed with increasing temperature. |
