Study of Ion Beam Alignment of Liquid Crystals on Polymer Substrates
Study of Ion Beam Alignment of Liquid Crystals on Polymer Substrates
复制标题
聚合物基板上液晶离子束配向的研究
DOI：
10.1080/15421400490440174
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发表时间：
2004
影响因子：
0.7
通讯作者：
Y. Reznikov
中科院分区：
文献类型：
--
作者：
J. Fulghum;L. Su;K. Artyushkova;J. West;Y. Reznikov
用Ar+离子束在高真空中以倾斜角度轰击各种聚合物衬底，包括聚酰亚胺和聚苯乙烯。无论使用何种聚合物，液晶5CB在这些聚合物衬底上的排列方向总是平行于离子束的传播方向。利用表面敏感技术，如偏振衰减全反射红外光谱（ATR-IR）和x射线光电子能谱，研究了对准机理。我们提出，Ar+离子束选择性地破坏聚合物中最弱的键（π键）会导致剩余π键的净过剩。这些π键的各向异性使液晶与离子束的传播方向平行。
Various polymer substrates, including polyimide and polystyrene were bombarded with an Ar+ ion beam in high vacuum at an oblique angle. The alignment direction of the liquid crystal 5CB on these polymer substrates is always parallel to the ion beam propagation direction regardless of the type of polymer used. The alignment mechanism is studied using surface sensitive techniques such as Polarized Attenuated Total Reflection Infrared Spectroscopy (ATR-IR), and X-ray Photoelectron Spectroscopy. We propose that selective destruction of the weakest bonds (π bonds) in the polymer by the Ar+ ion beam results in a net excess of the remaining π bonds. The anisotropy in these π bonds align liquid crystals parallel to the ion beam propagation direction.