On the Dynamic Character of “Ordered” Structure in Polymer Latex Suspensions

Abstract

A detailed microscopic study on polymer latex suspensions has been carried out. Particular emphasis is placed on the dynamic aspects of the ordered structure by using video imagery and an image data analyzer. This technique allows us to treat a large number of particles (usually 200 particles) over a longer time span, which improves considerably the reliability of the data compared to the almost “manual” treatment for a very limited number of particles as in our previous papers. The variation (actually disappearance) of localized ordered structures is demonstrated. The particles in the border regions between the ordered and disordered structures are also shown to be dynamic. The thermal motion of the particles in the ordered regions was found to be substantial at low concentrations. The thermal motion was found to be considerable at 10 and 60 °C but not so pronounced at 30 °C, which can be understood when the temperature dependence of the dielectric constant of water is taken into consideration. The motion of the particles in the coexisting ordered and disordered structures is compared. The results of the dynamical study indicated that a clear distinction must be made between the two coexisting structures, although the ordered structure is far from an ideal lattice. © 1988, American Chemical Society. All rights reserved.