Porous Poly(2-oxazoline)-Based Polymers for Removal and Quantification of Phenolic Compounds

The development of porous poly(2-oxazoline)-based polymers by a high internal phase emulsion procedure is reported. The porous polymers are obtained by cross-linking of short poly(2-oxazoline) chains possessing ester side chains using a triazabicyclodecene-catalyzed amidation reaction with diethylenetriamine as a cross-linker. The polymers are studied for adsorption of phenolic compounds, namely, 2,4-dichlorophenol, bisphenol S, and 2-naphthol as exemplary compounds. The influence of initial concentration, contact time, and pH on the adsorption process is investigated as well as the reusability of these porous polymers. The highest adsorption capacity is observed for adsorption of 2,4-dichlorophenol, and it reached 260 mg g–1. The adsorption kinetics for 2,4-dichlorophenol and bisphenol S are very fast as the maximum adsorption was reached after 30 and 15 min, respectively. Thermodynamic studies showed that the adsorption for 2,4-dichlorophenol and bisphenol S is entropy-driven, whereas the adsorption of 2-napthol is enthalpy-driven. The porous polymers are also used for quantification of the phenolic compounds by directly coupling them with ambient plasma mass spectrometry. The obtained limits of detection are two orders of magnitude lower than the ones obtained for analysis of the corresponding solutions, which include river samples. These results indicate that the porous poly(2-oxazoline)-based polymers possess a large potential for water purification as well as for the quantification of organic contaminants in water samples.