Can the isotropic-smectic transition of colloidal hard rods occur via nucleation and growth?

We investigate the isotropic-to-smectic transformation in a fluid of colloidal hard rods using computer simulations. At high supersaturation, we observe spinodal decomposition: many small clusters are formed at the initial stage of the phase transformation, which form a percolating network that eventually transforms into a stable bulk smectic phase. At low supersaturation, we find that nucleation and growth of the smectic phase is hampered by the pre-smectic ordering in the supersaturated isotropic fluid phase. As the system evolves mainly via cooperative motion of these smectic domains, the diffusion and attachment of single particles to the nucleation site is largely hindered.