Electric-Field-Induced Capillary Attraction between Like-Charged Particles at Liquid Interfaces



Birds of a feather, flock together. In a recent paper in Nature, Nikolaides and co-workers discuss the much debated issue of capillary attraction between like-charged particles at liquid interfaces. They show quite convincingly that dipolar electric fields induce surface charges that distort the interface; the dipolar interaction causes repulsion, while the interfacial distortion causes capillary attraction. The behaviour observed has broad implications for interfacial and colloid chemistry, when charged particles are present at fluid interfaces.