Homogeneously aligned liquid crystal molecules on reformed poly(methyl methacrylate) via ion-beam irradiation

• We demonstrated uniform LC alignment using IB-irradiated poly(methyl methacrylate) (PMMA) as an alignment layer.
• The characteristics of PMMA surface were investigated as functions of incidence angle.
• The PMMA irradiated with IB at an incidence angle of 30° had a higher molecular polarity than those of other incidence angles.
• The LC cells containing PMMA exhibited good thermal stability (180°) compared with LC cells containing conventional rubbed PI (150°).
• LC molecules on PMMA switched faster than those on conventional rubbed PI.

We demonstrated uniform LC alignment using IB-irradiated poly(methyl methacrylate) (PMMA) as an alignment layer. We confirmed the topographical changes on PMMA caused by IB irradiation. Moreover, the wettability and chemical modification of the PMMA surface were investigated as functions of incidence angle. The results show that PMMA irradiated with IB at an incidence angle of 30° had a higher molecular polarity than PMMA irradiated with IB at other incidence angles, resulting in strong van der Waals interactions between the surface and LC molecules. The LC cells containing PMMA irradiated with IB at an incidence angle of 30° exhibited good thermal stability (180°) compared with LC cells containing conventional rubbing PI (150°). In addition, LC molecules on PMMA irradiated with IB at an incidence angle of 30° were observed to switch faster than those on conventional rubbing PI. Therefore, PMMA irradiated with IB under the optimal conditions may allow for PMMA to be applied in advanced LC devices as an alternative alignment layer.

We demonstrated uniform LC alignment using IB-irradiated poly(methyl methacrylate) (PMMA) as an alignment layer. We confirmed the topographical changes on PMMA caused by IB irradiation. Moreover, the wettability and chemical modification of the PMMA surface were investigated as functions of incidence angle. The results show that PMMA irradiated with IB at an incidence angle of 30° had a higher molecular polarity than PMMA irradiated with IB at other incidence angles, resulting in strong van der Waals interactions between the surface and LC molecules. The LC cells containing PMMA irradiated with IB at an incidence angle of 30° exhibited good thermal stability (180°) compared with LC cells containing conventional rubbed PI (150°). In addition, LC molecules on PMMA irradiated with IB at an incidence angle of 30° were observed to switch faster than those on conventional rubbed PI. Therefore, PMMA irradiated with IB under the optimal conditions may allow for PMMA to be applied in advanced LC devices as an alternative alignment layer.Figure optionsDownload high-quality image (98 K)Download as PowerPoint slide