Self-nucleation of Patterned Polymer Thin Films Defined by Soft Lithography

The nucleation of crystals is often a determining step in the phase transition of materials, but it remains a challenge to control the density and specific location of nuclei simultaneously. Here we fabricated the isolated single crystals of uniform size with controlled number density and spatial distribution by self-nucleation of patterned dendritic crystals. Imprint lithography creates the periodic void space on the surface of poly(ethylene oxide)-b-poly(2-vinyl pyridine) (PEO-b-P2VP) block copolymer thin films and provides spatial redistribution of polymers, leading to the preferential nucleation and subsequent oriented growth of dendrites in the periodic arrays of imprinted lines. The morphology and thermal stability of the patterned crystals can be adjusted by tuning embossing conditions (e. g., temperature and pressure). Furthermore, in the self-nucleation technique, the annealing temperature and heating rate are used as the feedback parameters to map the number density and spatial distribution of regrown single crystals. Such PEO-b-P2VP crystalline pattern can be used as a versatile template for large-area manufacturing of selective metal patterns for electronic devices and other applications.