SURFACE-MORPHOLOGY OF POLYPYRROLE CORE POLYACROLEIN SHELL LATEX BY ATOMIC-FORCE MICROSCOPY (AFM)

Polypyrrole latex (P(P)), synthesized in Redox polymerization of pyrro le, was used as seed for radical polymerization of acrolein initiated with K2S2O8. In this process the polypyrrole core/polyacrolein shell l atex (P(P-A)) was obtained. Morphology of the surface of P(P-A) partic les was investigated by atomic force microscopy (AFM). It was found th at macromolecules of polyacrolein are ?or randomly distributed on the surface of polypyrrole but form patches. Apparently, attraction betwee n macromolecules of polyacrolein in the surface layer is high and the enthalpy of formation of polyacrolein macromolecule clusters is suffic ient to compensate, at least, the negative entropy change due to order ing of these macromolecules. Thickness of the polyacrolein layer on th e surface of polypyrrole particles, which were covered only partially with polyacrolein, was equal to only 1.6 nm (standard deviation sigma = 0.2 nm) and thus, it was reasonable to assume that it corresponded t o the monolayer coverage.