Small-Angle X-ray Scattering Analysis of the Radial Structure of Latex Particles Swollen by a Nonpolar Monomer

• DOI: 10.1021/la970106g
• Publication Date: 2002-07-26T05:15:42Z
• Authors: J. Bolze; K. D. Hörner; M. Ballauff
• Keywords: Small-angle X-ray scattering

A structural investigation of poly(methyl methacrylate) (PMMA) latex particles swollen by styrene is given. The goal this study to detect whether the polymer chains will be depleted at surface for entropic reasons (wall-repulsion effect) or enthalpic effects prevail driving nonpolar swelling agent into core particles. By use small-angle X-ray scattering in conjunction with contrast variation, radial structure could determined high resolution. In a layer about 1 nm thickness has been found which polymeric compound strongly enriched. This core−shell becomes more pronounced increasing amount added agent. From result it obvious that particular case studied here effect dominates: avoids water interface whereas polar enriched surface. finding, combination previous on PMMA MMA (J. Bolze, M. Ballauff, Macromolecules 1995, 28, 7429) shows may controlled and/or effects. agreement recent theoretical Evers et al. (Colloid Surf., 1994, 90, 135).