Effective Surface Functionalization of Carbon Fibers for Fiber/Polymer Composites with Tailor‐Made Interfaces

Abstract

Composites between carbon fibers (CFs) and heterogeneous materials have been widely studied and their fabrication techniques have been developed. However, their hydrophobic surfaces make it difficult to disperse CFs into hydrophilic resins, which results in weak junctions with ceramics. To develop high‐strength composite fibers, it is important to design interfacial chemical bonds. Thus, surface‐modification techniques of CFs have recently become the main focus and their interfaces have been characterized by various analytical methods. In this Minireview, various techniques that modify the CF surface by coating with inorganic polymers (metal oxide compounds) are highlighted, and the applications of novel nanocomposite fibers are also described. Furthermore, interfacial bonds between CFs and polymer resins are reviewed and discussed in terms of CF‐reinforced plastics and their future prospects.

Design Rules for Enhanced Interfacial Shear Response in Functionalized Carbon Fiber Epoxy Composites

“…Despite an extensive body of work on interfacial adhesion in composites, − the role of the fiber–matrix interface in conferring composite mechanical performance continues to be debated, particularly regarding the relative importance of chemical modification of the CF surface versus the influence of CF surface roughness in providing strong interfacial contact. − To this end, there are numerous experimental reports concerning the effect of reinforcement (fiber, nanotube, graphene, etc.) on polymer matrices for a range of composite properties, for example, thermal conductivity or composite stiffness. − …”

“…However, such treatments can yield a concomitant reduction in the single fiber properties, see, e.g., Montes-Morán et al The use of more complex molecules to functionalize the CF surface is relatively under-studied, due to the challenge in grafting various species onto this inert CF substrate, but has seen significant progress in recent years. This approach has taken many forms, including the direct grafting of small molecules, graphene, or nanoparticles onto the CF surface. − On a related note, substantial efforts have been spent in investigating surface functionalization of graphene and the generation of graphite–polymer composites with improved mechanical properties to study various properties, from thermal conductivity to mechanical strength. ,− …”

A review about the fluorination and oxyfluorination of carbon fibres

“…The most known are based on oxidative treatments [5][6][7], plasma treatments [8,9], electrografting [10,11], or chemical grafting of oxygenated [12] or nitrogenated [4,[13][14][15] species. Other innovative and promising methods exist, such as microwave irradiation [16,17], metal oxide coating [18,19], or bio-inspired functionalisation [20,21]. Independently of the retained method, similar trends are observed: fibre tensile properties are maintained, while fibre wetting with resin, interfacial shear strength (IFSS), and fibre-based composite tensile strength are improved.…”

Next generation high‐performance carbon fiber thermoplastic composites based on polyaryletherketones

“…There are examples of grafting nanoparticles to the surface of carbon fiber in order to improve matrix bonding . He et al .…”