Surface plasmon resonance imaging of liquid crystal anchoring on patterned self-assembled monolayers

The anchoring of the nematic liquid crystal (LC) 4'-n-octyl-4-cyanobiphenyl (8CB) at derivatized self-assembled monolayer (SAM) surfaces has been investigated using surface plasmon resonance (SPR) microscopy. Surfaces having distinct areas (patterns) covered by different omega-functionalized groups, one (-CF3) promoting homeotropic anchoring of the nematic director and the other (-OH) planar anchoring, were fabricated from photopatterned SAMs. Our results show that SPR microscopy, which is sensitive to the alignment on the mesoscale (i.e., within 300 nm of the interface) can be used to spatially resolve the anchoring of adsorbed LC films, with a lateral resolution on the order of a few micrometers, as a function of temperature. In addition, we observe surface melting of the crystalline phase at the SAM boundary by both homeotropic and planar aligned melts.