Department of Materials Science and Engineering, Yonsei University, Shinchon-Dong 134, Seodaemun-Gu, Seoul 120-749, Korea.
Langmuir. 2010 Apr 6;26(7):5072-6. doi: 10.1021/la903535c.
Long-term stability of intermediate liquid crystal pretilt angles on a poly(dimethylsiloxane) (PDMS) ultrathin film grafted onto a surface was realized simply and easily via low-energy ion beam (IB) treatment. The composition and surface energy of the thin film could be controlled by varying the low-energy IB treatment. This treatment results in the permanent chemical modification of the film surface, converting it from organic PDMS to a mixed layer of organic PDMS and inorganic silica. The partial transformation of a PDMS surface gives rise to the control of the pretilt angle via the formation of the inhomogeneous surface and the stabilization of the pretilt angle via the cross-linking reaction of broken chemical bonds through IB irradiation. As a result, a continuous variation of pretilt angles that maintained their initial value with long-term stability was obtained. Thus, the unique chemical transformation of the PDMS surface using IB treatment may allow for the production of durable intermediate liquid crystal pretilt angles.
通过低能离子束（IB）处理，可简单且轻松地实现聚二甲基硅氧烷（PDMS）超薄薄膜在表面上的中间液晶预倾角的长期稳定性。通过改变低能 IB 处理，可以控制薄膜的组成和表面能。这种处理导致薄膜表面的永久化学改性，将其从有机 PDMS 转化为有机 PDMS 和无机二氧化硅的混合层。PDMS 表面的部分转化导致通过形成非均匀表面来控制预倾角，并且通过 IB 照射破坏化学键的交联反应来稳定预倾角。结果，获得了预倾角的连续变化，其初始值保持长期稳定性。因此，使用 IB 处理对 PDMS 表面进行独特的化学转化可能会产生持久的中间液晶预倾角。
