Latex macrocrystal self-assembly dependence on particle chemical heterogeneity

A self-arrayed poly(styrene-co-hydroxyethylmethacrylate) film surface was examined using microscope techniques possessing microchemical capabilities, together with standard (control) techniques. Secondary electron (SEI) and backscattered electron (BEI) images obtained in a field-emission scanning microscope, as well as scanning atomic force (AFM) and electric potential (SEPM) images, show an accumulation of hydrophobic particles around point and line macrocrystal defects. Defects in self-arrayed latex films are thus largely due to latex particle chemical heterogeneities. This result is consistent with the capillary adhesion-dependent models for macrocrystal formation and it shows the importance of latex purification, prior to macrocrystallization.