Institute for Technology, Research and Innovation, Deakin University, Geelong, Victoria 3217, Australia.
J Chem Phys. 2009 Dec 7;131(21):214905. doi: 10.1063/1.3268779.
We present a study of microphase separation induced by competitive hydrogen bonding in A-b-B/C diblock copolymer/homopolymer complexes where the diblock copolymer A-b-B is immiscible and the homopolymer C can interact unequally with both A and B blocks through hydrogen bonding. A model system containing poly(2-vinyl pyridine)-block-poly(methyl methacrylate) (P2VP-b-PMMA) and poly(4-vinyl phenol) (PVPh) in tetrahydrofuran was investigated. In these self-assembled complexes, microphase separation takes place due to the disparity in intermolecular interactions. Specifically, PVPh and P2VP blocks interact strongly to form complex, whereas PVPh and PMMA blocks interact weakly. The hydrogen bonding interactions were revealed by infrared spectroscopy and analyzed in terms of the difference in interassociation constants (K), i.e., interaction parameters of each blocks of the block copolymer to the homopolymer and according to the random phase approximation. The phase behavior of the complexes was investigated with small-angle x-ray scattering and transmission electron microscopy. A series of morphologies including lamellae, hexagonal cylinders, wormlike microdomains, and hierarchical structures was documented as a function of the copolymer concentration. Moreover, we outlined how hydrogen bonding determines the self-assembly and causes morphological transitions in different A-b-B/C diblock copolymer/homopolymer systems with respect to the K values.
我们研究了在 A-b-B/C 嵌段共聚物/均聚物复合物中由竞争氢键引起的微相分离，其中嵌段共聚物 A-b-B 是不混溶的，而均聚物 C 可以通过氢键与 A 和 B 嵌段不均等地相互作用。我们研究了含有聚（2-乙烯基吡啶）-嵌段-聚（甲基丙烯酸甲酯）（P2VP-b-PMMA）和聚（4-乙烯基苯酚）（PVPh）在四氢呋喃中的模型体系。在这些自组装复合物中，由于分子间相互作用的差异，发生了微相分离。具体来说，PVPh 和 P2VP 嵌段强烈相互作用形成复合物，而 PVPh 和 PMMA 嵌段相互作用较弱。氢键相互作用通过红外光谱揭示，并根据相互关联常数（K）的差异进行分析，即嵌段共聚物的每个嵌段与均聚物的相互作用参数，并根据无规相近似进行分析。通过小角 X 射线散射和透射电子显微镜研究了复合物的相行为。记录了一系列形态，包括层状、六方圆柱、蠕虫状微区和分层结构，作为共聚物浓度的函数。此外，我们概述了氢键如何决定自组装并在不同的 A-b-B/C 嵌段共聚物/均聚物体系中引起形态转变，这与 K 值有关。
