Physical Review Letters · 1989 · 267 citations · 13 references
Natural SciencesChemistryMaterials SciencePhysical ChemistryPolymer ChemistrySurface SciencePolymer BlendsPolymer PhysicsPolymer SurfacesSurface EnergeticsSurface EnergySurface PhysicsMean-field TheoryPolymer Surface AnalysisPolymer Surface ChemistryPolymer Surface EnergyPolystyreneSurface Energy DensitySurface ExcessVolume Fraction Effects
Forward-recoil spectrometry reveals that the surface of a blend of deuterated polystyrene ($d$-PS) and protonated polystyrene (PS) is enriched with $d$-PS relative to the bulk; the surface excess of $d$-PS increases almost linearly with the bulk volume fraction $\ensuremath{\varphi}$ of $d$-PS at 184\ifmmode^\circ\else\textdegree\fi{}C. The results may be interpreted quantitatively with mean-field theory, and yield a form of the bare surface energy of the blend consistent with the surface enrichment being driven by a surface-energy difference between $d$-PS and hydrogenated polystyrene ($h$-PS) of isotopic origin.
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