CBE PhD Thesis Defense: “BIJEL-Templated Advanced Functional Materials for a Sustainable Future”

Advanced functional materials comprising multiple components with nano- and microscopic features typically rely on expensive and time-consuming fabrication methods. Kinetically-trapped disordered structures provide a powerful alternate route to fabricate fault-tolerant, multi-component functional structures at scale. Developing such structures with controllable features that could serve as materials templates for various applications is of great importance. Bicontinuous interfacially jammed emulsion gels (bijels) are kinetically trapped disordered biphasic materials that can be converted to porous materials with tunable features. The self-assembled nature of the bijel structure, coupled with its remarkable flexibility in terms of features and constituent materials, positions it as a highly promising material for the advancement of functional porous materials. However, the practical utilization of bijels is hindered by several challenges that need to be addressed. This study aims to overcome these challenges by simplifying the fabrication process, improving control over bijel features, and demonstrating their practical functions. To achieve scalable fabrication, the vaporization induced phase separation (VIPS) method is introduced, enabling bijel production under ambient conditions. The importance of quenching kinetics is also revealed, leading to the achievement of bijels with uniform sub-micrometer domains through regulated co-solvent removal. Furthermore, the unique structure of bijels allows for intriguing interactions with light, fluids, and electrons. This is exemplified by the successful development of bijel templated passive radiative cooling coatings and carbon air cathodes, showcasing the exceptional functionality of bijels.