Adjusting the free-surface condition facilely controls the in-plane and out-of-plane orientations in liquid crystalline polymer (LCP) films. Top coating with aromatic molecules onto LC polymethacrylate films with N-benzylideneaniline (NBA) or 4-methoxybiphenyl (MB) side groups (PNBAM or PMBM) and subsequent annealing generate a random planar orientation while simultaneously removing the coated aromatic molecules, whereas annealing noncoated films induces a homeotropic orientation of the mesogenic side groups. Additionally, irradiating a top-coated PNBAM film with linearly polarized (LP) 365 nm light induces an in-plane molecular reorientation of the NBA side groups without changing the orientation in the homeotropically oriented region. Changes in the surface topology of the LCP films due to the reorientation processes are investigated in detail. Inkjet coating with aromatic molecules and LP 365 nm light exposure precisely controls the in-plane and out-of-plane alignment pattern in a PNBAM film.

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Diblock and random copolymers are synthesized from a methacrylate with benzoic acid (BA) side groups and a nbutyl methacrylate, and the photoinduced reorientation of thin films doped with a N-benzylideneaniline carboxylic acid (NBA), which governs the H-bond with BA, is investigated using linearly polarized (LP) 365 and 313 nm light. A sufficient thermally stimulated photoinduced orientation of the BA side groups and simultaneous sublimation of NBA are attained for the diblock copolymer films, whereas a thermal treatment results in the random orientation of the random copolymers. Furthermore, surface relief (SR) formation of the film is explored when the NBA-doped films are exposed to LP light using a photomask. The liquid crystalline characteristics, thermal properties, axis-selective photoisomerization, and the photo-cross-linking of the film play important roles in the molecular reorientation and SR formations.

Polymethacrylates with different type of cinnamate side groups (P1, P2 and P3) were synthesized, and their photochemical and photoinduced reorientation behaviors were investigated using linearly polarized (LP) 313 nm and 365 nm light. P1 and P2 exhibited liquid crystalline (LC) characteristics, but P3 did not. Thin P1 and P2 films underwent thermally stimulated photoinduced molecular reorientation using LP 313 nm or 365 nm light and subsequent annealing, where adjusting the exposure energy and the exposing light wavelength could control the reorientation direction. Type of the cinnamate side groups, resultant photoproducts, and LC characteristics of the polymer played an important role in the thermally stimulated photoinduced molecular reorientation directions and their performances.