Bottom-up self-synthesis of supramolecular Pickering emulsions by interfacial dynamic combinatorial chemistry

Pickering emulsions stabilized by interfacially adsorbed particles are attractive synthetic compartmentalized soft materials, but conventional particle stabilizers are usually pre-synthesized and structurally static. Supramolecular chemistry provides a route to dynamic particle stabilizers, yet weak supramolecular interactions often limit their stabilization at dynamic liquid-liquid interfaces, impairing emulsion stability. Here, we report an interfacial dynamic combinatorial chemistry (DCC) strategy for the in-situ formation of supramolecular interfacial particles that stabilize water-in-oil (W/O) Pickering emulsion. These interfacial particles are assembled from dynamic combinatorial libraries (DCLs) of anionic macrocyclic disulfides templated by a cationic surfactant (CTAB) at the oil-water interface, producing Pickering emulsion with low stabilizer concentrations (≤0.9 wt%) and dramatically enhanced stability. Remarkably, the molecular-level adaptation of interfacial DCLs led to emergent upper-level structures and properties, from nano-sized SIPs with optimized hydrophobicity and size for W/O interfacial stabilization, to macro-sized W/O droplets, and finally semi-solid self-healing emulsion with stress relaxation behavior. The interfacial environment enriches larger macrocyclic disulfides relative to bulk DCL controls, while varying the precursor concentration enables fine-tuning of macrocycle distribution and further mechanical properties of emulsions. Our results establish interfacial DCC as a promising strategy that bridges molecular selection, interfacial assembly, and macroscopic emulsion mechanics, providing a route to adaptive Pickering emulsions and dynamic interfacial materials.