Structure of Polystyrene at the Interface with Various Liquids

Abstract

Vibrationally resonant sum frequency generation (VR-SFG) is used to determine the structure of the phenyl side groups of deuterated polystyrene at the liquid/solid interface for the nonsolvent liquids hexane, methanol, ethanol, glycerol, and water. The structure for the three low-surface-tension (γ) liquidshexane, methanol, and ethanolis similar and only slightly perturbed from that of the air/solid interface. The air interface is ordered with the phenyl rings oriented away from the polymer bulk. The structure for the two high-γ liquids, water and glycerol, differs significantly from the low-γ liquids and reflects a near flat orientation of the phenyl ring.