Molecular reorientation of polyimide film induced by thermal nanoimprint lithography and liquid crystals alignment on it

•The molecular orientations of imprinted polyimide films with different film thickness were characterized.•The orientation of liquid crystals was influenced by surface structure of imprinted polyimide film.•The molecular orientation of imprinted polyimide film in the residual layers and the one in the higher-lines were different.

The molecular orientations of thermally imprinted polyimide (PI) films with different film thickness were investigated by the polarized Fourier-transform infrared spectroscopy (P-FTIR). The results illustrated the molecular orientation in the residual layers and the one in the higher-lines were different. The polymer main chains in the residual layers were perpendicular to the lines and parallel to the substrate. The polymer main chains in the higher-lines were aligned normal to the substrate and CO bonds perpendicular to the main chain were aligned along the line direction. The orientation of liquid crystals on the alignment layer was investigated by atomic force microscopy (AFM) and polarized optical microscopy (POM). The results demonstrated imprinted PI film could be an alignment layer for liquid crystals.

Graphical abstractDownload high-res image (243KB)Download full-size image