Engineering with Graphene for Multi-functional Coatings and Fibre-Composites

石墨烯是一种由单层碳原子组成的材料，但颗粒的线性尺寸可能在毫米范围内。它具有一系列显著的性能，当添加到聚合物材料中时，可以提供潜在的好处，包括增韧、导电性、自润滑和阻燃性。石墨烯固有的二维几何结构有利有弊；具体来说，它指导我们在薄层的应用，如涂层，它的几何形状可以最好地利用。这些应用本质上也需要相对少量的填充物来产生显著的影响，从而有效地利用最初可能可用的相对少量的石墨烯。石墨烯与现有最先进的商业系统相结合，通过增强现有材料，是一条特别有希望快速商业化的途径。这项研究的总体目标是展示石墨烯如何在复合工程环境中使用，以改善当前聚合物基材料的性能。关键的挑战是明确定义的石墨烯材料的分散和功能化，以及将其与选定的聚合物系统相结合的加工路线的发展。这是必不可少的，以避免凝聚作为缺陷，并最大化化学相互作用与基质，以避免不必要的分层。原生石墨烯薄片的应力传递测量表明，为了有效增强，它们必须保持几十微米的平面；但明智地使用非破坏性的功能化途径，应该会将这一要求至少放宽一个数量级。优化的表面化学是与基体相互作用和有效处理真正剥落石墨的关键。我们将利用我们特定的、可扩展的、内部的路线来生产功能化的、分散的石墨烯，同时将框架损坏降到最低。因此，第一个挑战是以可扩展的方式生产具有正确功能的石墨烯，以确保与所用矩阵的良好兼容性和最佳性能改进。该小组已经确定了两条可能的路线，由于我们不知道先验的最有效的路线，我们将调查这两条路线。这些改性的石墨烯将以适度的百分之几的负载与基质结合，以创建优化的复合系统，足以在以下应用中提供功能涂层的好处。此外，基本方面是创造高石墨烯含量复合材料的机会，并控制石墨烯在结构形成中的分布，以利用其独特的内在特性。为了应对这一挑战，我们将开发三种替代路线来制造大面积石墨烯基薄膜；这些系统提供了一种更激进的方法来实现更大的潜在改进。将测量改性石墨烯和聚合物共混物的基本机械和物理性能，以确定最有前途的材料。我们将把这些石墨烯材料与相关的基体结合起来，特别是环氧/聚酯树脂，用于以下应用：复合材料零件的脱模和功能性涂层，纤维复合材料飞机和风力涡轮机叶片的雷击保护和改进的屏障性能；适用于管网（包括阀门）和机械系统的坚韧、低渗透、耐刮擦和自润滑功能涂层；而防火涂料则凭借增强的阻隔性能和炭的形成。

Graphene is a material comprising a single layer of carbon atoms, yet particles can have linear dimensions potentially in the millimetre range. It has a remarkable set of properties that offer potential benefits when added to polymer materials, including toughening, electrical conductivity, self-lubrication and fire retardance. The intrinsic two-dimensional geometry of graphene has pros and cons; specifically, it directs us towards applications in thin layers, such as for coatings where its geometry can best be utilised. These applications also intrinsically require relatively small quantities of filler for a significant impact, thus making efficient use of relatively small quantities of graphene that are likely to be available initially. The combination of graphene with existing state-of-the-art commercial systems is a particularly promising route to rapid commercialisation through the enhancement of current materials.The overall aim of the proposed research is to show how graphene can be used in a composite engineering context, to improve the properties of current polymer-based materials. The key challenges are the dispersion and functionalisation of well-defined graphene material, and the development of processing routes to combine it with the selected polymer systems. It is essential to avoid agglomerates that act as defects, and to maximise the chemical interaction with the matrix to avoid unwanted delamination. Measurement of stress transfer in native graphene flakes indicate that they must remain flat over many tens of microns for efficient reinforcement; but the judicious use of non-damaging functionalisation routes should relax this requirement by at least an order of magnitude. Optimised surface chemistry is the key both to interaction with the matrix in-service and to effective processing of truly exfoliated graphite. We will exploit our specific, scalable, in-house routes to functionalised, dispersed graphenes with minimised framework damage. Thus the first challenge is to produce graphene in a scalable manner with the correct functionality to ensure good compatibility with the matrices used and optimum property improvement. The team have identified two potential routes, and as we do not know a priori which will be the most effective we will investigate both. These modified graphenes will be combined with matrices at modest loadings of a few percent, to create optimised composite systems sufficient to offer benefits to functional coatings in the applications described below. A further, fundamental aspect is the opportunity to create high graphene content composites and to control the graphene distribution in the formation of structures designed to take advantage of its unique intrinsic properties. To meet this challenge, we will develop three alternative routes for the creation of large area graphene-based films; these systems offer a more radical approach to even greater potential improvements. The basic mechanical and physical properties of the modified graphene and polymer blends will be measured to identify the most promising materials. We will combine these graphene materials with relevant matrices, especially epoxy/polyester resins for the following applications: mould release and functional coatings for composite parts, lightning-strike protection and improved barrier properties for fibre-composite aircraft and wind-turbine blades; tough, low permeability, scratch resistant, and self-lubricating functional coatings for applications in pipe networks (including valves) and mechanical systems; and fire-resistant coatings by virtue of enhanced barrier properties and char formation.