Nanostructured Composite Coatings to Harden and Toughen Polymer Surfaces

由于其低密度、高韧性、易于加工和低成本，聚合物在广泛的应用中发挥着越来越重要的作用，包括电子、车辆、建筑材料以及工业和家用电器。然而，与金属和陶瓷相比，聚合物具有相当差的耐刮擦性和耐磨性。增强聚合物的耐刮擦/耐磨性的常用方法是在其表面上添加硬涂层。然而，许多常规的硬涂层对聚合物的粘附性差，并且容易破裂。此外，用于硬涂层的传统沉积方法通常在负压下进行，使得它们昂贵且难以实施大面积加工。这项工作的目标是研究一类新的纳米结构涂层，具有高的耐刮擦性和抗裂性，可以使用廉价的可扩展的方法生产。这项工作的动机是最近成功地创建纳米复合材料涂层与极高浓度的纳米粒子的基础上渗透的聚合物到纳米粒子薄膜。这些涂层可以直接在聚合物表面上形成，以产生具有非常强的附着力和高耐刮擦性的涂层。耐刮擦纳米复合硬质涂层有可能用作下一代能量存储和转换设备以及光学、生物传感器和电子设备的关键部件。 此外，此类材料还可用作电子产品和食品包装中的屏障。该团队将开发演示复合材料性能的模块，用于计划面向学生、教师和公众的外展活动。该项目将建立通过毛细上升渗透（CaRI）将聚甲基丙烯酸甲酯渗透到三水铝石纳米片薄膜中生产的砖和砂浆结构的纳米复合材料涂层的加工-结构-性能关系。 该项目是两名研究人员之间的合作：Lee，纳米结构材料的制造和结构及光学表征专家，以及Turner，材料和力学专家。该项目将解决必须理解和克服的基本问题，以推进CaRI材料和纳米复合材料的一般领域。具体而言，将通过改变聚合物的分子量及其相对于纳米片膜中的特征孔径的大小来研究空间限制对大聚合物通过纳米多孔介质的毛细上升和运输的影响。此外，通过利用CaRI工艺的多功能性和可调谐性，将建立复合涂层的内部结构与其机械和光学性能之间的关系。通过加工、表征和建模，我们将对CaRI复合材料的加工-结构-性能关系有一个全面的了解。

Owing to their low density, high toughness, ease of processing and low cost, polymers are playing increasingly important roles in a broad set of applications, including electronics, vehicles, building materials, and industrial and household appliances. Compared to metals and ceramics, however, polymers have rather poor scratch- and wear-resistance. A common approach to enhance the scratch/wear resistance of polymers is to add hard coatings on their surfaces. However, many conventional hard coatings suffer from poor adhesion to the polymer and can crack easily. Furthermore, the conventional deposition methods for hard coatings are often done under negative pressure, making them expensive and challenging to implement for large-area processing. The goal of this work is to investigate a new class of nanostructured coatings that have high scratch and crack resistance and can be produced using an inexpensive scalable method. This work is motivated by recent success in creating nanocomposite coatings with extremely high concentrations of nanoparticles based on infiltration of polymers into nanoparticle films. These coatings can be formed directly on the surface of polymers to produce coatings that have very strong adhesion and high scratch resistance. Scratch resistant nanocomposite hard coatings can potentially be used as key components of next-generation energy storage and conversion devices as well as optical, biosensors and electronic devices. Also, such materials have applications as barriers in electronics and food packaging. The team will develop modules demonstrating the properties of composite materials for use at outreach events planned for students, teachers and the general public.This project will establish the processing-structure-property relationships of brick-and-mortar structured nanocomposite coatings produced via capillary rise infiltration (CaRI) of poly(methylmethacrylate) into films of gibbsite nanoplatelets. The project is a collaboration between two investigators: Lee, an expert in the fabrication and structural and optical characterization of nanostructured materials, and Turner, an expert in materials and mechanics. The project will address fundamental issues that must be understood and overcome to advance CaRI materials and the general area of nanocomposites. Specifically, the effect of spatial confinement on the capillary rise and transport of large polymers through nanoporous media will be studied by changing the molecular weight of the polymer and its size relative to the characteristic pore size in the nanoplatelet film. Furthermore, by taking advantage of the versatility and tunability of the CaRI process, the relationship between the internal structure of the composite coatings and their mechanical and optical properties will be established. Through processing, characterization, and modeling, we will develop a holistic understanding of processing-structure-property relationship of CaRI composites.