State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China.
Langmuir. 2011 Apr 19;27(8):4351-7. doi: 10.1021/la200314t. Epub 2011 Mar 15.
A large number of lozenge-shaped and sandwiched polystyrene-block-poly(L-lactide) (PS-b-PLLA) single crystals were prepared by the self-seeding technique. The single crystals were nearly monodispersed in both thickness and diameter. They are well-dispersed because of the steric stabilization offered by tethered PS in p-xylene, which is a good solvent for PS. The suspensions were observed to separate into a transparent upper phase and a turbid lower phase. The lower phase showed uniform iridescent stripes extending over the whole tube between crossed polarizers. The birefringence demonstrates the liquid crystal order, and the uniform stripes reveal that the phase is a well-oriented single domain. The phase-transition concentration is rather low. Polarizing light microscopy (PLM) images show Schlieren texture and thread-like texture. Small-angle X-ray scattering (SAXS) results showed that the single crystals in the liquid crystal phase oriented horizontally with a vertical repeat distance of about 70 nm. Additionally, the possible structure of the liquid crystal phase is being discussed. The novel disclike colloidal particle might be useful for anisotropic photonic materials.
大量的长方块形和夹心型聚苯乙烯-聚（L-丙交酯）（PS-b-PLLA）单晶是通过自种晶技术制备的。这些单晶在厚度和直径上几乎是单分散的。由于 tethered PS 在对 PS 为良溶剂的 p-二甲苯中提供的空间位阻稳定作用，它们得以很好地分散。悬浮液被观察到分成透明的上层和混浊的下层。下层在正交偏光显微镜下呈现出均匀的虹彩条纹，延伸到整个管内。双折射表明存在液晶有序性，而均匀的条纹表明该相是一个取向良好的单畴。相转变浓度相当低。偏光显微镜（PLM）图像显示出普弹性织构和线状织构。小角 X 射线散射（SAXS）结果表明，在液晶相中，单晶以约 70nm 的垂直重复距离水平取向。此外，还讨论了液晶相的可能结构。这种新型的盘状胶体颗粒可能对各向异性光子材料有用。
