The adsorption of a copolymer of vinyl pyrrolidone and allylamine at the silica-solution interface

Abstract

The conformation of a copolymer of vinyl pyrrolidone and allylamine adsorbed at the silica-solution interface has been studied by EPR spectroscopy. Spin labels attached at random along the polymer backbone have allowed the fractions of segments in trains and loops to be measured. The polymer changed from a relatively flattened conformation to a more looped one with increasing surface coverage; the effect on the conformation of changing solvent from pure water to 0–1 N NaCl or chloroform was small. The time for changes between the flattened and looped conformation was less than 2 min and bridging of the polymer molecules between silica particles was demonstrated.