Synthesis of Patchy Particles at Phase Boundaries.

Functional patchy particles, distinguishing themselves from isotropic colloids through different discrete surface domains, are critical for advanced applications such as colloidal assembly, catalysis, and biomedical purposes. In this review, we focus on the elaboration of patchy particles, categorizing the different synthesis strategies based on the specific interfacial environments employed to induce asymmetry. Recent advances, as a function of the various interfacial constraints, are reviewed: (1) solid-gas interfaces, which exploit physical shadowing for directional deposition; (2) liquid-gas interfaces, taking advantage of surface tension and wettability to create tunable dynamic masks for selective modification; (3) solid-liquid interfaces, utilizing surface immobilization to restrict chemical access or induce site-selective growth; and (4) liquid-liquid interfaces, where soft boundaries facilitate symmetry breaking via thermodynamic partitioning, confinement induced assembly, and bipolar electrochemistry. By revealing the relationship between interfacial synthesis conditions, the triggered chemical reactions, and the final particle features, this review aims to provide practical insights and design principles for engineering next-generation patchy particles with tailored complexity.