摘要
甲壳型液晶高分子可以呈现超分子柱或片层的链构象,因此可以作为超分子液晶基元形成多种液晶相态,如六方柱状相、柱状向列相、六方柱状向列相、近晶相等.将纳米构筑单元,如一维的二联苯、二维的苯并菲、三维的多面体低聚倍半硅氧烷(POSS)等,引入到甲壳型液晶高分子中,所得聚合物可以自组装形成在亚十纳米和近纳米尺度的多级有序结构.这些结构具有尺寸可控及单分散的优点,可望在有机光电、纳米多孔膜以及纳米光刻等领域有着广阔的应用前景.本文主要介绍了将二联苯、偶氮苯、棒状多苯结构、苯并菲和POSS基元引入到甲壳型液晶高分子中制备多级组装结构的相关工作.
The conformation of a mesogen-jacketed liquid crystalline polymer（MJLCP） chain can be a supramolecular rod or sheet. Therefore, MJLCPs can serve as supramolecular mesogens to form various liquid crystalline（LC） phases, such as hexagonal columnar, columnar nematic, hexatic columnar nematic, and smectic phases. By introducing nanobuilding blocks such as one-dimensional biphenyl, two-dimensional triphenylene and three-dimensional polyhedral oligomeric silsesquioxane（POSS） into MJLCPs, the resultant polymers can self-assemble into hierarchical structures on the sub-10 nm and close-to-1 nm length scales, as proven by a combination of experimental techniques including differential scanning calorimetry, polarized light microscopy, wide-angle and small-angle X-ray scattering, and transmission electron microscopy. In general, polymers form hierarchical structures at low temperatures. With increasing temperature, the ordered structure of the nanobuilding blocks in the side chain becomes disordered first. When the temperature is further elevated, the nano-sized LC phase of the polymer as a whole will transform to another structure or become isotropic. For some polymers, a re-entrant isotropic phase exists at intermediate temperatures. Because the hierarchical structures of these polymers have the advantages of controllable sizes and monodispersity and LC polymers are capable of being aligned by external fields and forming large-scale ordered domains, such polymers have wide potential applications in organic opto-electronics, nanoporous membranes, nanolithography, and so on. This paper reviews research works on the design, synthesis, and hierarchical self-assembly of MJLCP-based homopolymers containing biphenyl, azobenzene, calamitic multi-benzene structure, triphenylene, and POSS units in the side chains.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
2017年第7期1038-1046,共9页
Acta Polymerica Sinica
关键词
甲壳型液晶高分子
纳米构筑单元
二联苯
苯并菲
多面体低聚倍半硅氧烷
Mesogen-jacketed liquid crystalline polymer
Nanobuilding block
Biphenyl
Triphenylene
Polyhedral oligomeric silsesquioxane（POSS）
