Predicting and manipulating the organization particulates in suspension has seen decades of investigation. Understanding the structures and properties of materials produced by association relies descriptions of incorporating thermal and interparticle forces and often requires models for cooperative phenomena. While great advances have been made in describing the physical processes that underlie changes in states of aggregation, the surface chemistry resulting in variations in interaction energies remain difficult to characterize and predict. Recent studies demonstrate the significance of both the range and strength of centro-symmetric interactions while there is growing evidence that anisotropic interactions play a significant role in controlling the details of both ordered and disordered structures. In this talk progress in prediction of conditions resulting in ordered assembly and in the formation of gels will be described. Challenges limiting progress and opportunities for new directions in the control of microstructure and mechanical properties are a theme that will be developed.