Department of Polymer Science, College of Polymer Science and Polymer Engineering, University of Akron, Akron, OH 44325-3909, USA.
Proc Natl Acad Sci U S A. 2013 Jun 18;110(25):10078-83. doi: 10.1073/pnas.1302606110. Epub 2013 May 28.
The engineering of structures across different length scales is central to the design of novel materials with controlled macroscopic properties. Herein, we introduce a unique class of self-assembling materials, which are built upon shape- and volume-persistent molecular nanoparticles and other structural motifs, such as polymers, and can be viewed as a size-amplified version of the corresponding small-molecule counterparts. Among them, "giant surfactants" with precise molecular structures have been synthesized by "clicking" compact and polar molecular nanoparticles to flexible polymer tails of various composition and architecture at specific sites. Capturing the structural features of small-molecule surfactants but possessing much larger sizes, giant surfactants bridge the gap between small-molecule surfactants and block copolymers and demonstrate a duality of both materials in terms of their self-assembly behaviors. The controlled structural variations of these giant surfactants through precision synthesis further reveal that their self-assemblies are remarkably sensitive to primary chemical structures, leading to highly diverse, thermodynamically stable nanostructures with feature sizes around 10 nm or smaller in the bulk, thin-film, and solution states, as dictated by the collective physical interactions and geometric constraints. The results suggest that this class of materials provides a versatile platform for engineering nanostructures with sub-10-nm feature sizes. These findings are not only scientifically intriguing in understanding the chemical and physical principles of the self-assembly, but also technologically relevant, such as in nanopatterning technology and microelectronics.
不同尺度结构的工程设计是控制宏观性质的新型材料设计的核心。在此，我们介绍了一类独特的自组装材料，这些材料是基于形状和体积保持的分子纳米颗粒和其他结构基元（如聚合物）构建的，可以看作是相应小分子对应物的尺寸放大版本。其中，通过在特定位置将紧凑且极性的分子纳米颗粒“点击”到各种组成和结构的柔性聚合物尾部，可以合成具有精确分子结构的“巨型表面活性剂”。巨型表面活性剂具有小分子表面活性剂的结构特征，但尺寸更大，在自组装行为方面兼具两种材料的双重性。通过精确合成对这些巨型表面活性剂的结构特征进行控制，可以进一步表明它们的自组装对主要化学结构非常敏感，导致在大块、薄膜和溶液状态下具有高度多样、热力学稳定的纳米结构，特征尺寸约为 10nm 或更小，这是由集体物理相互作用和几何约束决定的。结果表明，该类材料为工程具有亚 10nm 特征尺寸的纳米结构提供了一个通用平台。这些发现不仅在理解自组装的化学和物理原理方面具有科学意义，而且在纳米图案化技术和微电子技术等方面也具有技术相关性。
