Get the full paper: Soft Matter, 4, 663 (2008). Janus particles, named after the double-faced Roman god, are compartmentalized colloids with two sides of different chemistry or polarity. This makes them a unique class of materials among micron- or nanosized particles. Due to this special non-centrosymmetric feature in the particle architecture, the synthesis of Janus particles remained challenging for a long time. However, major progress concerning their preparation in useful