3D Structural Visualization from Polymer Nanocomposite Scattering*

Polymer nanocomposites are often composed of ramified aggregates in a polymer matrix, for example silica reinforced elastomers, carbon black reinforced polyethylene for pipes, lithium salt composites with PEO for solid electrolytes. The design and modeling of these nanocomposites requires visualization of these complex 3d structures and their emergent multi-hierarchies. It is possible to parameterize these nanocomposites using small-angle scattering, reflecting an average of the hierarchical structures. Due to the loss of phase information, a direct transform to a 3d visualization is not possible. However, within the constraints of a hierarchical aggregate structure, it is possible to simulate 3d aggregates that match the degree of branching, convolution, tortuosity, degree of aggregation, mass, and hierarchical sizes of those in nanocomposites. This process can be conducted dynamically, such as during drying of ink or paint, to visualize the growth of emergent complex hierarchical structures. Verification of the visualizations is demonstrated using cryo-TEM. The 3d visualizations are used as a starting point for simulations of multi-hierarchical assembly and structural emergence in nanocomposites such as reinforced elastomers and paints.