Optimization of hybrid hyperbranched polymer/ceramic filters for the efficient absorption of polyaromatic hydrocarbons from water

A series of alumina filters with different pore surface areas, varying pore size distributions and mean pore diameters were impregnated by poly(ethylene imine) hyperbranched polymer functionalized with octyl aliphatic chains. Impregnation percentage was analogous to the hyperbranched polymer solution concentration and also depended on the filter pore surface areas. These observations permitted the manufacturing of filters with variable impregnation percentages. Implementation of two successive immersions of alumina into the polymer solution permitted much more uniform pore coating at the nanoscale as established by scanning electron microscopy. The property of these composite filters to encapsulate lipophilic polyaromatic organic pollutants dissolved in water via continuous filtration experiments has been examined and correlated to the structural characteristics of the filters, the polymer impregnation percentage and the overall impregnation procedure. These results allowed the optimization of the impregnation procedure affording hybrid tube filters that absorb 98% of phenanthrene and 55% of the far more water-soluble β-naphthol.