Surface complexation modeling of Fe(3)O(4)-H(+) and Mg(II) sorption onto maghemite and magnetite

New fluorinated copolymers of poly(methyl methacrylate)-b-poly(butyl methacrylate) or poly(n-octadecyl methacrylate) end-capped with 2-perfluorooctylethyl methacrylate (PMMA(x)-b-PBMA(y)-ec-PFMA(z) or PMMA(x)-b-PODMA(y)-ec-PFMA(z)) were synthesized by living atom transfer radical polymerization. Thin films made of PMMA(230)-b-PODMA(y)-ec-PFMA(1) were characterized by differential scanning calorimetry, angle-resolved X-ray photoelectron spectroscopy and X-ray diffraction. These films were found to exhibit robust surface segregation of the end groups. Furthermore, the fluorine enrichment factor at the film surface was found to increase linearly with increasing degree of polymerization of poly(n-octadecyl methacrylate) and its increasing fusion enthalpy in the second block, which enhances the segregation of the fluorinated moieties.