  The physical gelation of colloids produces elastic structures that are
commonly used to stabilize complex fluids in multiple industries. However, the
ability to control the level of elastic modulus of these materials is limited
by the universality of the arrested spinodal decomposition mechanism that
governs their formation. We demonstrate that manipulating particle shape can
yield very large shifts in gel elasticity relative to this universal behavior,
and that these changes are generated by a set of independent mechanisms that
act multiplicatively. Modeling demonstrates that this efficient generation of
elasticity is the consequence of the combined effects of shape anisotropy on
the hierarchical fractal microstructure of the gel network, the anisotropy of
the attractive interparticle pair potentials, and the volumetric compactness of
the fractal cluster. The findings show how and why particle anisotropy can be
exploited to generate elasticity at ultra-low colloidal volume fractions in
this important class of soft matter.
