Hierarchical Structures in Lamellar Hydrogen Bonded LC Side Chain Diblock Copolymers
Hierarchical Structures in Lamellar Hydrogen Bonded LC Side Chain Diblock Copolymers
复制标题
DOI：
10.1021/ma300820q
复制
发表时间：
2012-08
期刊：
影响因子：
5.5
通讯作者：
A. Soininen;Ioanna Tanionou-;N. T. Brummelhuis;H. Schlaad;N. Hadjichristidis;O. Ikkala;J. Raula;R. Mezzenga;J. Ruokolainen
中科院分区：
文献类型：
--
作者：
A. Soininen;Ioanna Tanionou-;N. T. Brummelhuis;H. Schlaad;N. Hadjichristidis;O. Ikkala;J. Raula;R. Mezzenga;J. Ruokolainen
我们表明，在氢键键合的LC侧链二嵌段共聚物与层状形态的嵌段共聚物的水平上，两个不同的包装机制的侧链嵌段是可能的，这取决于氢键键合的侧链的量。我们将氢键介晶胆甾醇半琥珀酸酯（CholHS）与聚（1，2-丁二烯）-嵌段-聚（2-乙烯基吡啶）（PBd-P2 VP）和聚（苯乙烯）-嵌段-聚（4-乙烯基吡啶）（PS-P4 VP）混合，其中聚（乙烯基吡啶）充当主体嵌段，并且我们改变CholHS与吡啶重复单元的比率（x）。对于所有x，实现嵌段共聚物水平上的层状形态。然而，在低结合的CholHS的主机块，CholHS侧链微相分离成一个单一的层内的聚（吡啶）层，导致在一个新的微相分离的结构。这包括例如x = 0.25的PS-P4 VP样品和所有基于PBd-P2 VP的样品，因为CholHS与P2 VP的氢键在空间上受到限制，如通过红外光谱所揭示的。
We show that in a hydrogen bonded LC side chain diblock copolymer with lamellar morphology on the block copolymer level, two distinct packing mechanisms of the side chain blocks are possible depending on the amount of hydrogen bonded side chains. We mixed a hydrogen bonding mesogen, cholesteryl hemisuccinate (CholHS), with poly(1,2-butadiene)-block-poly(2-vinylpyridine) (PBd-P2VP) and poly(styrene)-block-poly(4-vinylpyridine) (PS-P4VP), in which the poly(vinylpyridine) act as host blocks, and we varied the CholHS to pyridine repeat unit ratio (x). With all x, a lamellar morphology on the block copolymer level was achieved. However, at low binding of CholHS to the host block, the CholHS side chains microphase separated into a single layer inside the poly(pyridine) lamellae resulting in a novel microphase separated structure. This includes, for example, the PS-P4VP sample with x = 0.25 and all the PBd-P2VP based samples since hydrogen bonding of CholHS to P2VP was sterically limited as revealed by infrared ...