Polymer/Nanoparticle Interface in Polymer Nanocomposites: A Critical Review

For the past few decades, polymer nanocomposites (PNCs) have attracted a great deal of attention both scientifically and commercially. By incorporating a small proportion of nanoparticles (NPs) in polymer matrices, the bulk properties of the PNCs have been shown to be significantly improved compared to neat polymer matrices. NPs are characterized by large surface area (hundreds of square meters per gram) enabling high level of interfacial interactions with the polymer matrix. The interface region determines the level of stress, and heat and electrical transport phenomena. The main difficulty that has been encountered in PNCs is the tendency of inorganic or organic NPs to agglomerate due to their large surface areas and intrinsic particle to particle interaction, competing with particle to polymer interactions. Different approaches have been suggested to tailor the surface of the NPs to be compatible with the host polymer matrix with the objective to increase the interfacial adhesion. This review is aimed to survey the NP/polymer interfacial region and analyze the strategies that have been used to control the interface both chemically or physically for specific polymer matrices. Finally, the review evaluates the interfacial effects of NPs on the resultant PNCs micro/macro properties.