Films of polystyrene (PS) and poly(methyl methacrylate) (PMMA) blend have been annealed at a temperature above their glass transition temperatures for up to 48 h. Surface chemical compositions of the cast and annealed films were measured by X-ray photoelectron spectroscopy (XPS) while surface topographical changes were followed by atomic force microscopy (AFM). The blend films spin-cast from chloroform produce nonequilibrium surfaces with a significant excess of PMMA. The polymer component with a lower surface free energy, PS, is shown to segregate to the surface upon annealing. The PS surface concentration of the films, containing 50% PS:50% PMMA in the bulk, was evaluated using the ester peak in XPS C 1s spectra (sampling depth ∼ 9 nm) and found to increase from ∼5% (freshly spin-cast film) to a saturated level of ∼47% after 17 h of annealing. AFM imaging reveals evolution of blend morphology with annealing time. The spin-cast films prior to annealing exhibit pitted topography with typical pit size of ∼1.2 μm and depth of 30−40 nm. As the annealing process proceeds, these pits get continually shallower. Frictional force microscopy with hydroxylated tips recorded surface phase separations for the films of 2−4 h annealing. As the annealing continues to above 14 h, the pitted structure becomes distorted. The surface enrichment and morphology changes upon annealing are explained by dewetting of PMMA relative to PS.

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The surface oxygen content of selected wood-based phosphoric acid-activated carbons was quantified using X-ray photoelectron spectroscopy (XPS) and correlated with the residual bulk phosphate levels of the carbons and their adsorptivity in solution. The adsorption of Al 3+ , Cu 2+ , and parachlorophenol, respectively, from water decreased as a function of increasing surface oxygen content of the carbons. When the carbon of lowest surface oxygen content was oxidized with ozone to impart a surface oxygen content comparable to that of a carbon with a much higher phosphate level, adsorption of Al 3+ , Cu 2+ , and para-chlorophenol from water decreased proportionally. The increase in polarity of the carbon surface was accompanied by a decrease in pH and appeared to be the dominant factor with respect to the adsorption of the target species from water.