The washing effects on liquid crystal (LC) alignment capability in a NLC, 4-n-pentyl-4′-cyanobiphenyl (5CB), on a rubbed polyimide (PI) surface containing the trifluoromethyl moiety were studied. The extrapolation length de of 5CB on the rubbed PI surface decreases with the rubbing strength RS. Also, the large extrapolation length de of 5CB for washing with IPA was measured at RS = 114 mm. The polar anchoring energy of 5CB on the rubbed PI surface was decreased by the washing process; it increased with the rubbing strength RS on the PI surface. The surface order parameter S S of 5CB for all the washing processes is smaller than for the non-washing process. Consequently, the polar anchoring energy and surface order parameter SS in 5CB are largely attributed to washing effects.
Bibliographical noteFunding Information:
This work was supported by the National Research Laboratory program (M1-0203-00-008).
All Science Journal Classification (ASJC) codes
- Materials Science(all)
- Condensed Matter Physics