The validity of the micro-mixing phenomenon was investigated by mixing a melamine dispersion, stabilized by low molecular mass poly(acrylic acid) (similar to 5000 Daltons) and a wax emulsion, stabilized by an ethoxylated alkyl phenol surfactant. The wax particles were observed to be attached to the melamine surface because of the interaction between the poly(acrylic acid) dispersant and the ethoxylate group of the wax surfactant, resulting in the sedimentation of mixed particles. This phenomenon has potential application in the mixing of solid particles that require intimate contact and homogeneous mixing. (c) 2005 Wiley Periodicals, Inc.