Polymer Nanocomposite as a Highly Inhomogeneous and Disordered Medium

Polymer-based composites were proposed as a new paradigm for materials in the 1960s. By dispersing stiff fibers in a polymer matrix, high-performance lightweight composites were developed [1]. Utilization of epoxy composites in the engineering field has tremendously increased in the last decade due to their unique properties such as high strength-to-weight ratio and design flexibility [2–5]. However, some obstacles hinder the application of these materials such as low impact toughness and poor adhesion of hydrophilic reactive groups with polymer matrix. Currently, one of the most challenging research areas of nanotechnology focuses on the inclusion of nanoparticle fillers into polymers to enhance the functional and physical properties of the polymers. Nanofillers can be used to improve the adhesion in composites or the interlaminar strength of the matrix [6]. Among various nanoparticles, graphene, which allows to achieve good dispersion and can be incorporated in both hydrophilic and hydrophobic polymers, is also systematically employed [7–9]. The creation of polymer nanocomposites with functionalized graphene overcomes many significant obstacles posed by filler inclusion deteriorating effects and provides superb polymer-particle interactions [10]. In this respect, the properties of the interfacial zone between the host polymer and the surface-modified nanoparticles are a tremendously important issue in successfully designing the engineering material.