Nanometer-Scale Molecular Cluster Surfactants Generate Robust Gel Emulsion Systems for Solid-State Electrolytes

Pickering emulsions stabilized by colloidal particles or their mixtures with surfactants have received increasing interest in recent years, but few of them can produce gel emulsions with practical stability. Herein, robust gel emulsions can be facilely prepared through the charge attraction-driven complexation and enrichment of negatively charged coordination nanocages (CNCs) and cationic surfactants at liquid/liquid interfaces. Due to CNCs’ ultrasmall sizes (∼2.5 nm) and highly charged features, they strongly interact with surfactants to jam the biphasic interfaces and endow the formed membranes with high cohesive energy densities, leading to the robust formation of gel emulsions with widely tunable liquid compositions. Moreover, the gel emulsions possess promising mechanical strength up to 10⁴ Pa and the biphasic membranes can maintain their 3D hierarchical structures when both liquids are removed. Their preparation can be feasibly scaled up, enabling their applications in hierarchical porosity construction, gas adsorption, and solid-state electrolytes.