A previous study demonstrated that relatively monodispersed particles of poly(styrene-co-acrylonitrile) (SAN) can be prepared through the phase inversion of water-in-oil (W/O) to oil-in-water (O/W) emulsions containing a water-soluble organic solvent as the oil phase. In this study, we apply the phase inversion method to binary polymer blend systems, i.e., SAN and polystyrene (PS), poly(styrene-co-butadiene) (PSB), or polycyclohexylmethacrylate (PCM). The size distributions of particles produced from the binary polymer blends of SAN + PS and SAN + PSB, but not of SAN + PCM, are carried out by adding the distributions of the original single polymers, where a single SAN system produces small particles (below 1 mm), while the main products of the single PS and PSB systems are large particles with broad size distributions. After small particles below 2 mm and large particles above 10 mm are collected by filtrating as-prepared particle dispersions, FT-IR analysis of the collected particles reveals that the small particles contain mainly SAN and the large particles are enriched with PS or PSB. Accordingly, we demonstrate that the phase inversion method fulfills a fractionation potential of binary polymer blends into the original components based on particle size difference. (C) 2017 Elsevier Ltd. All rights reserved.