Accelerated Ripening in Chemically Fueled Emulsions

Marta Tena-Solsona, Jacqueline Janssen, Caren Wanzke, Fabian Schnitter, Hansol Park, Benedikt Rieß, Julianne M. Gibbs, Christoph A. Weber and Job Boekhoven

ChemSystemsChem https://doi.org/10.1002/syst.202000034

Abstract

Chemically fueled emulsions are solutions with droplets made of phase‐separated molecules that are activated and deactivated by a chemical reaction cycle. These emulsions play a crucial role in biology as a class of membrane‐less organelles. Moreover, theoretical studies show that droplets in these emulsions can evolve to the same size or spontaneously self‐divide when fuel is abundant. All of these exciting properties, i. e., emergence, decay, collective behavior, and self‐division, are pivotal to the functioning of life. However, these theoretical predictions lack experimental systems to test them quantitively. Here, we describe the synthesis of synthetic emulsions formed by a fuel‐driven chemical cycle, and we find a surprising new behavior, i. e., the dynamics of droplet growth is regulated by the kinetics of the fuel‐driven reaction cycle. Consequently, the average volume of these droplets grows orders of magnitude faster compared to Ostwald ripening. Combining experiments and theory, we elucidate the underlying mechanism.