Particle‐stabilized emulsion gels, or bijels, are used as a general platform for the synthesis of bicontinuous composite materials with various chemistries and morphologies. The method enables the use of ceramics and metals in novel applications where the unique transport and electrochemical properties offered by minimal surface structures may be exploited.

The development of model materials and image processing methods to directly visualize and quantify colloidal rod assembly by means of confocal laser scanning microscopy (CLSM) is reported. Monodisperse fluorescent colloidal rods are prepared by the uniaxial extensional deformation of sterically stabilized microspheres at elevated temperatures. The particles are stably dispersed in refractive index matching mixed organic solvents for CLSM. An image processing algorithm is developed to detect rod backbones and extract particle centroids and orientation angles from the CLSM image volumes. By means of these methods we quantify the distribution of rod orientation angles in self-assembled structures of rods formed by sedimentation. We find the observations to be consistent with aspect-ratio-dependent jamming and orientational order/disorder transition in the rod sediments.

Confocal microscopy and rheology studies of two bijel systems are presented to elucidate relationships between the physicochemical properties of bijels and their ability to be utilized as soft matter templates for materials synthesis. For the first time, the origins of viscoelasticity in these systems are investigated using conventional rheometry and a direct correspondence between the elastic storage modulus, particle loading, and the departure from criticality is observed. Further, the rheological transitions that accompany fluid re‐mixing in bijels are characterized, providing key insights into the synergistic role of interfacial tension and interparticle interactions in mediating their mechanical robustness. Bijels that are predominantly stabilized by interfacial tension are also highly sensitive to gradients in chemical composition and more easily prone to mechanical failure during processing. Despite this increased sensitivity, a modified strategy for processing these more delicate systems is developed and its efficacy is demonstrated by synthesizing a bicontinuous macroporous hydrogel scaffold.