(526b) Novel Bicontinuous Materials Derived From Colloidal Bijels

Macroporous materials with tunable morphology and chemistry find utility in a wide variety of current technologies including tissue engineering, separations, and catalysis. Materials possessing bicontinuous morphology are unique in that two phases coexist in convoluted, percolating pathways throughout the sample volume, which can lead to intriguing and useful mechanical, electrochemical, and transport properties. In this work, we present a novel approach for fabricating bicontinuous, macroporous materials with tunable chemistry and morphology using a colloidal bijel template. Bijels are particle-stabilized emulsion gels formed by interfacial assembly and jamming of neutrally wetting colloidal particles in a binary liquid mixture undergoing spinodal decomposition. Utilizing the thermodynamic incompatibility of the fluid domains, we selectively polymerize one continuous phase of the bijel to create a macroporous polymer template whose characteristic domain/pore size can be adjusted between less than 10 and over 100 µm solely by adjusting the initial colloid volume fraction. Quantitative confocal microscopy confirms that both the bijel and its polymerized counterpart possess the characteristics of a 3D spinodal structure. We further utilize our macroporous polymer templates to synthesize a novel family of ceramic, metallic, and composite bicontinuous structures, and discuss their prospective applications in emerging technologies including catalysis, microfluidic sensing, and fuel cells.