In
the present work, crystallization-driven coassembly of micrometric
polymer single crystals and nanometric block copolymer micelles was
achieved. The hybrid single crystals are first formed by cocrystallization
of polyethylene (PE) homopolymer and polyethylene-<i>b</i>-poly(<i>tert</i>-butyl acrylate) (PE-<i>b</i>-P<i>t</i>BA) block copolymer (BCP) in DMF or DMF/<i>o</i>-xylene mixed solvent. The morphology of the obtained hybrid
single crystals can be regulated via changing the solvent composition,
crystallization temperature and mass ratio of BCP/homopolymer. Because
of the difference in crystallization rate, the distribution of PE-<i>b</i>-P<i>t</i>BA BCP in the hybrid single crystals
may be inhomogeneous, leading to a concave gradient surface structure.
The hybrid single crystals have a double-layer structure, in which
PE homopolymer chains adopt extended conformation and the PE blocks
in PE-<i>b</i>-P<i>t</i>BA are probably once-folded.
After the PE homopolymer is consumed, cylindrical micelles of PE-<i>b</i>-P<i>t</i>BA can further epitaxially grow on
the lateral surface of the hybrid single crystals and “ciliate
paramecium-like” coassemblies are yielded. The single crystal/micelles
coassemblies can be prepared either by one-step method, in which PE
and PE-<i>b</i>-P<i>t</i>BA are added together
in a single step, or by two-step method, in which the hybrid single
crystals are prepared in the first step and extra PE-<i>b</i>-P<i>t</i>BA is added in the second step to grow BCP micelles.
This work provided a simple route to construct hierarchical assemblies
composed of objects with different scales by using crystallization
as the key driving force
