Sorption of hydrophobic compounds by modified poly(ethylene oxide) networks

Various flocculates were prepared by irradiation and chemical modification of poly(ethylene oxide). It was found that the amphiphilic hydrogels are efficient for purification of waste waters and water-organic systems contaminated with dyes and pigments, even at low concentrations (0.035-0.1 wt.-%) of the polymeric PEO network flocculates. The affinity of the modified networks for ionic and nonionic species was studied as a function of the structure and crosslinking density of the networks, their degree of quaternization, and their hydrophilicity coefficients. It was established that hydrophobic organic compounds such as sodium picrate and bromophenol blue are bound predominantly to the lipophilic quaternary ammonium cations. The polyether chains remain inert (in the case of nonionic dyes) or form complexes with the alkali cations (in the case of sodium picrate). It was also found that the microenvironment of the active site (quaternary N+ ion or EO segment) affects the sorption ability of the modified networks.