界面自组装多层纳米粒子薄膜的制备、表征及机理研究

The fabrication of nanoparticle films is currently one of the most attractive areas of self-assembly of nanomaterials. It has potential application in modern electronics, energy, information storage and biomedicine due to its wide range of optical, electrical, and thermal properties. Rationally controlling properties of the nanoparticle films relies on precisely tuning the structural metrics within the film such as nanoparticle size, composition, spacial arrangement, film microstructures and nanoparticle layer order. However, previous efforts in different nanoparticle self-assembly at interface were restricted to two dimensional single nanoparticle layer (i.e. all different nanoparticles co-assembled within one layer). Achieving size, composition-segregated, multilayered nanoparticle film, however, still remains a significant hurdle, especially in a simple one-step assembly process. In this project, we propose a novel synthetic method that allows one to synthesize size, composition-segregated multilayer nanoparticle film. Mechanistic study of interfacial nanoparticle self-assembly will be performed to understand the relation among the properties of individual nanoparticles, experimental conditions and nanoparticle film morphology. We aim to not only establish a conceptual framework to precisely tailor the structural parameters of size, composition-segregated multilayer nanoparticle films but also further control the physical and chemical properties of the films. We expect that these multilayer nanoparticle films generated via “bottom-up” assembly method could be broadly utilized in electrical device, electrocatalysis, plasmonic heating and other related areas.

纳米粒子薄膜制备是当前纳米自组装技术研究领域中最具吸引力的分支之一，由于它在光、电、热等方面有着优异的性能，因此可广泛应用于现代电子器件、环境能源、信息存储、生物医学等领域。然而宏观控制纳米粒子薄膜的性能需要做到能精确调控薄膜内纳米粒子的尺寸、组成、空间位置的排布、薄膜表面的微结构乃至薄膜内纳米粒子层纵向叠加形式等结构因素。目前国内外对纳米粒子界面自组装局限于在二维同种粒子层组装，对于不同尺寸、种类等纳米粒子在界面有序地纵向分层叠加自组装成三维层状粒子薄膜的研究却未有报道。本项目计划探索全新的薄膜自组装机制，合成一系列不同粒子尺寸、种类的纳米颗粒纵向分层叠加薄膜。通过研究组装规律，确立纳米粒子属性、实验参数和纳米粒子薄膜结构形态之间的联系，实现精确调控三维多层层状薄膜内纳米粒子尺寸、种类，从而使其宏观性能可控化，并促进其在电子器件、电催化、光致发热等领域的广泛应用。

纳米粒子薄膜制备是当前纳米自组装技术研究领域中最具吸引力的分支之一，由于它在光、电、热等方面有着优异的性能，因此可广泛应用于现代电子器件、环境能源、信息存储、生物医学等领域。然而宏观控制纳米粒子薄膜的性能需要做到能精确调控薄膜内纳米粒子的尺寸、组成、空间位置的排布、薄膜表面的微结构乃至薄膜内纳米粒子层纵向叠加形式等结构因素。因此本研究立足于三方面研究，即：1）不同尺寸和种类的纳米颗粒纵向分层组装双层薄膜的制备及其表征；2）探索组装薄膜材料的物理化学性能及其应用；3）组装薄膜材料的物理化学性能模型建立和模拟计算。在不同尺寸、种类纳米粒子组装薄膜方面，本研究通过金纳米颗粒或石墨烯等碳材料沉积在无尘纸或者其他多孔材料上制备双层复合薄膜，通过物理或化学修饰复合材料表面，控制材料多种不同的表面形态（相关工作见：Advanced Materials, 2015, 27, 2768–2774; Journal of the American Chemical Society, 2017, 139(36), 12362-12365；Nanoscale, 2017, 9, 19384– 19389）。基于前期对不同组装薄膜材料全新的理解和探索，以仿生为研究契机，结合贵金属及石墨烯碳基纳米材料的光热效应，仿造生物体的特殊构造，制备了一系列光、热等功能性复合材料，并成功地应用于热能的储存、传输，热蒸发和表面催化等领域（ACS Applied Materials & Interfaces, 2016, 8, 14628–14636; ACS Applied Materials & Interfaces, 2016, 8 (1), 772–779）。本课题由前期组装纳米粒子薄膜的制备及其微观结构对宏观光电、光热性能影响研究经验，已经初步认识并提出了光吸收及光热转换机制的模型，具体模拟计算部分发表在（Advanced Materials, 2015, 27, 2768–2774）。详细的光热转换机制涉及到光子与声子的转换，具体研究尚在进行，还未发表。本课题旨在实现精确调控三维多层层状薄膜内纳米粒子尺寸、种类，从而使其宏观性能可控化，并促进其在电子器件、电催化、光致发热等领域的广泛应用。