Constructing 2D gold nanorods monolayer films with precise particle assembly is of great importance to fundamental and real applications. However, it is usually difficult to achieve macroscopic size, freestanding feature, high density of particle packing, and precisely controllable particle orientation in monolayer films. In this work, a macroscopic, uniform, freestanding orientational monolayer film is facilely and controllably prepared through precise assembly of asymmetrically modified gold nanorods at water–oil interface. The assembling morphologies can be controlled through regulating the interaction between gold nanorods by varying the amounts and sites of modified molecules. The intriguing tunable assemblies exhibit not only adjustable absorption spectrum in a wide range attributed to different particle coupling, but also optimized photothermal conversion capability under low energy density (0.08 W cm^‐2). Together with a commercial thermochromic dye, the patterned assemblies show excellent photothermal anti‐counterfeiting performance by reproducing accurate full images in 20 s that are invisible after laser off in 10 min. The excellent laser writing performance is also demonstrated by writing any information on thermochromic dye‐coated assemblies. With the advantages of being macroscopic, equipment‐free, transferable, scalable and with high photothermal conversion capability, the orientational monolayer films pave the way for on‐demand design of sensing and device applications.

中文翻译：

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具有优异的光热防伪性能的宏观取向金纳米棒单层膜

构建具有精确粒子组装的2D金纳米棒单层膜对于基础和实际应用都非常重要。然而，通常难以在单层膜中实现宏观尺寸，独立特征，高颗粒堆积密度以及精确可控的颗粒取向。在这项工作中，通过在水-油界面处精确组装不对称修饰的金纳米棒，可以轻松，可控地制备宏观，均匀，独立的定向单层膜。可以通过改变修饰分子的数量和位置来调节金纳米棒之间的相互作用来控制组装形态。引人入胜的可调组件不仅具有宽广的可调吸收光谱，归因于不同的粒子耦合，^‐2）。图案化的组件与市售的热致变色染料一起使用，可在20 s内重现准确的完整图像（在激光关闭10分钟后不可见），从而显示出出色的光热防伪性能。通过在热致变色染料涂层组件上写入任何信息，也证明了出色的激光写入性能。定向单层薄膜具有宏观，无需设备，可转移，可扩展以及具有高光热转换能力的优势，为传感和设备应用的按需设计铺平了道路。