Dipping and photo-induced liquid crystal alignments using silane surfactants

Dipping and photo-induced liquid crystal (LC) alignments were demonstrated using new silanes as surface coupling agents. In the dipping method, both h omogeneous and homeotropic alignments can be achieved depending on the alky l chain length of the silane employed. The 110 degrees C post curing temper ature makes the dipping method especially attractive for low temperature pr ocessing of active matrix displays. In the UV-induced LC alignment, homogen eous cells are obtained and the LC directors are perpendicular to the impin ging UV polarization. The pretilt angle of both methods is found to be simi lar to 0.5 degrees.