Mojtabavi Mehrnaz, VahidMohammadi Armin, Ganeshan Karthik, Hejazi Davoud, Shahbazmohamadi Sina, Kar Swastik, van Duin Adri C T, Wanunu Meni
Department of Bioengineering, Northeastern University, Boston, Massachusetts 02115, United States.
Innovation Partnership Building, UConn TechPark, University of Connecticut, Storrs, Connecticut 06269, United States.
ACS Nano. 2021 Jan 26;15(1):625-636. doi: 10.1021/acsnano.0c06393. Epub 2021 Jan 6.
Bottom-up assembly of two-dimensional (2D) materials into macroscale morphologies with emergent properties requires control of the material surroundings, so that energetically favorable conditions direct the assembly process. MXenes, a class of recently developed 2D materials, have found new applications in areas such as electrochemical energy storage, nanoscale electronics, sensors, and biosensors. In this paper, we present a lateral self-assembly method for wafer-scale deposition of a mosaic-type 2D MXene flake monolayer that spontaneously orders at the interface between two immiscible solvents. ReaxFF molecular dynamics simulations elucidate the interactions of a MXene flake with the solvents and its stability at the liquid/liquid interface, the prerequisite for MXene flakes self-assembly at the interface. Moreover, facile transfer of this monolayer onto a flat substrate (Si, glass) results in high-coverage monolayer films with uniform thickness and homogeneous optical properties. Multiscale characterization of the resulting films reveals the mosaic structure and sheds light on the electronic properties of the films, which exhibit good electrical conductivity over cm-scale areas.
将二维（2D）材料自下而上组装成具有新特性的宏观形态需要控制材料周围环境，以便能量有利条件引导组装过程。MXenes是一类最近开发的二维材料，已在电化学储能、纳米级电子学、传感器和生物传感器等领域找到新应用。在本文中，我们提出了一种用于晶圆级沉积镶嵌型二维MXene薄片单层的横向自组装方法，该单层在两种不混溶溶剂的界面处自发排列。ReaxFF分子动力学模拟阐明了MXene薄片与溶剂的相互作用及其在液/液界面的稳定性，这是MXene薄片在界面处自组装的先决条件。此外，将该单层轻松转移到平坦基板（硅、玻璃）上可得到具有均匀厚度和均匀光学性质的高覆盖率单层膜。对所得薄膜的多尺度表征揭示了镶嵌结构，并阐明了薄膜的电子性质，这些薄膜在厘米级区域表现出良好的导电性。
