Kinetic and Thermodynamic Hysteresis in Clustering of Gold Nanoparticles: Implications for Nanotransducers and Information Storage in Dynamic Systems

Hysteresis is an essential attribute of many solid-state devices and biological processes, yet it is often overlooked in colloidal and soft-matter dynamic systems. Herein, we show that gold nanoparticles can remain dispersed or aggregated at the same temperature depending on the trajectory of applied stimulus, featuring hysteretic behavior. Aided by real-time analytics and fine-tuning of experimental parameters, such as salt concentration, nanoparticle diameter, and surface potential, we disentangled the kinetic (rate-dependent) and thermodynamic (rate-independent) components of hysteresis in cyclic clustering of nanoparticles. The hysteresis originates from the difference in the aggregation and disassembly temperatures. Our findings enrich the repertoire of the experimental framework with potential for stimuli-sensitive nanotransducers, information storage, switchable catalysis, or autonomous chemical networks with feedback loops.