Department of Chemistry, University of Massachusetts Amherst , 300 Massachusetts Avenue, Amherst, Massachusetts 01003, United States.
ACS Nano. 2017 Jul 25;11(7):7223-7229. doi: 10.1021/acsnano.7b03109. Epub 2017 Jun 24.
Recently, investigation on two-dimensional (2D) organic polymers has made great progress, and conjugated 2D polymers already play a dynamic role in both academic and practical applications. However, a convenient, noninterfacial approach to obtain single-layer 2D polymers in solution, especially in aqueous media, remains challenging. Herein, we present a facile, highly efficient, and versatile "1D to 2D" strategy for preparation of free-standing single-monomer-thick conjugated 2D polymers in water without any aid. The 2D structure was achieved by taking advantage of the side-by-side self-assembly of a rigid amphiphilic 1D polymer and following topochemical photopolymerization in water. The spontaneous formation of single-layer polymer sheets was driven by synergetic association of the hydrophobic interactions, π-π stacking interactions, and electrostatic repulsion. Both the supramolecular sheets and the covalent sheets were confirmed by spectroscopic analyses and electron microscope techniques. Moreover, in comparison of the supramolecular 2D polymer, the covalent 2D polymer sheets exhibited not only higher mechanical strength but also higher conductivity, which can be ascribed to the conjugated network within the covalent 2D polymer sheets.
最近，二维（2D）有机聚合物的研究取得了重大进展，共轭 2D 聚合物已经在学术和实际应用中发挥了重要作用。然而，在溶液中，特别是在水介质中，获得单层 2D 聚合物的简便、非界面方法仍然具有挑战性。在此，我们提出了一种简便、高效、通用的“1D 到 2D”策略，用于在水中制备无支撑的单分子厚的自由共轭 2D 聚合物，无需任何辅助。通过利用刚性两亲性 1D 聚合物的并排自组装，并在水中进行拓扑光聚合，实现了 2D 结构。单层聚合物片的自发形成是由疏水相互作用、π-π 堆积相互作用和静电排斥的协同作用驱动的。通过光谱分析和电子显微镜技术证实了超分子片和共价片的形成。此外，与超分子 2D 聚合物相比，共价 2D 聚合物片不仅具有更高的机械强度，而且具有更高的导电性，这归因于共价 2D 聚合物片中的共轭网络。
