Unraveling the Driving Forces in the Self-Assembly of Monodisperse Naphthalenediimide-Oligodimethylsiloxane Block Molecules.
Unraveling the Driving Forces in the Self-Assembly of Monodisperse Naphthalenediimide-Oligodimethylsiloxane Block Molecules.
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DOI：
10.1021/acsnano.6b08380
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发表时间：
2017-04-25
期刊：
影响因子：
17.1
通讯作者：
Meijer EW
中科院分区：
文献类型：
--
作者：
Berrocal JA;Zha RH;de Waal BFM;Lugger JAM;Lutz M;Meijer EW
嵌段分子是材料化学中一个快速发展的研究领域，在该领域中，离散的大分子结构弥合了嵌段共聚物（BCP）和液晶（lc）之间的差距。BCP和LCs特性的融合有望带来令人兴奋的突破，例如发现意想不到的形态或在具有高清晰度有机分子和聚合物可加工性的材料中显着缩小域间距。在这里，我们报道了由萘二亚胺（NDIs）和低聚二甲基硅氧烷（ODMS）组成的两个单分散块分子家族的大块自组装。这些材料具有蜡质结构、强长程有序和极低的迁移率，具有典型的构象无序晶体的性质。我们的研究明确地揭示了热力学不混溶性和结晶性指导了odms基嵌段分子的自组装。我们发现，ndi的块和结晶之间的高度不相容的协同作用导致纳米相分离，从而获得具有亚10nm周期性的六边形填充柱状（Colh）和层状（LAM）形貌。可以通过混合具有不同ODMS长度和相同ndi数量的分子来调整结构域间距，从而引入额外的控制层。x射线散射实验显示，当这种结构偏差没有被观察到时，大相分离。最后，我们强调了我们的“成分方法”，通过建立在晶体“硬”部分和不兼容的“软”ODMS伙伴上的简单策略，在亚10nm结构材料中获得完美的有序。遵循这个简单的规则，我们的方法可以扩展到许多系统。
Block molecules belong to a rapidly growing research field in materials chemistry in which discrete macromolecular architectures bridge the gap between block copolymers (BCP) and liquid crystals (LCs). The merging of characteristics from both BCP and LCs is expected to result in exciting breakthroughs, such as the discovery of unexpected morphologies or significant shrinking of domain spacings in materials that possess the high definition of organic molecules and the processability of polymers. Here we report the bulk self-assembly of two families of monodisperse block molecules comprised of naphthalenediimides (NDIs) and oligodimethylsiloxanes (ODMS). These materials are characterized by waxy texture, strong long-range order, and very low mobility, typical properties of conformationally disordered crystals. Our investigation unambiguously reveals that thermodynamic immiscibility and crystallization direct the self-assembly of ODMS-based block molecules. We show that a synergy of high incompatibility between the blocks and crystallization of the NDIs causes nanophase separation, giving access to hexagonally packed columnar (Colh) and lamellar (LAM) morphologies with sub-10 nm periodicities. The domain spacings can be tuned by mixing molecules with different ODMS lengths and the same number of NDIs, introducing an additional layer of control. X-ray scattering experiments reveal macrophase separation whenever this constitutional bias is not observed. Finally, we highlight our “ingredient approach” to obtain perfect order in sub-10 nm structured materials with a simple strategy built on a crystalline “hard” moiety and an incompatible “soft” ODMS partner. Following this simple rule, our recipe can be extended to a number of systems.