Abstract
Photoaligned monomolecular layers containing two materials were formed to control pre-tilt angles (θp) of liquid crystal molecules for twisted nematic (TN) type liquid crystal displays (LCDs) by a chemical adsorption (CA) technique and a photoalignment technique. One was a new chlorosilane type surfactant, 4'-(6-trichlorosilyloxyhexyloxy) chalcone (CO), having photopolymerizablity, and the other was a surfactant having a straight carbon chain (SC). Although we tried screening six different surfectants as an additive to CO, a surfactant having a long straight hydrocarbon chain (octadecyl-trichlorosilane: C18) was the most suitable for the TN type LCDs. By changing the molecular ratio of CO and C18, pre-tilt angles of liquid crystal molecules in a test liquid crystal (LC) cell could be controlled from 0 to 8° with perfect mono-domain alignment. When surfactants having short hydrocarbon chains and those having fluorocarbon chains were used, the quality of the TN type LC cells obtained was not good.