Effects of electrochemical oxidation of carbon fibers on interfacial shear strength using a micro-bond method

Abstract

In this work, we studied the effects of electrochemical oxidation treatments of carbon fibers (CFs) on interfacial adhesion between CF and epoxy resin with various current densities. The surface morphologies and properties of the CFs before and after electrochemical-oxidation-treatment were characterized using field emission scanning electron microscopy, atomic force microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and single-fiber contact angle. The mechanical interfacial shear strength of the CFs/ epoxy matrix composites was investigated by using a micro-bond method. From the results, electrochemical oxidation treatment introduced oxygen functional groups and increased roughness on the fiber surface. The mechanical interfacial adhesion strength also showed higher values than that of an untreated CF-reinforced composite.

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

“…This improved the interfacial shear stength with an epoxy matrix by nearly 10% and increased the fiber tensile strength by 16%. In a similar study, carbon fibers electrochemically oxidized in aqueous ammonium bicarbonate solution showed a 40% improvement of interfacial shear strength in an epoxy matrix, while preserving carbon fiber mechanical strength . Figure compares the fracture morphologies of micro‐bond test specimens containing untreated and electrochemically oxidized carbon fibers.…”

Electrochemical Activity and Damage of Single Carbon Fiber

“…To further illustrate the chemical state of surface-treated CFs, some researchers have also quantified the hydrophilicity through measuring the contact angles of CFs [ 29 ]. Meanwhile, a single CF pullout test has been conducted to evaluate the mechanic performance of CFs with different surface microstructures [ 1 , 30 , 31 ]. These investigations have led to many significantly deepened understandings of the CF surface microstructure and behavior.…”

“…Although all the above investigations have clearly indicated that strong polarization can alter the surface state of a CF, no effort has been made to look into the detailed electrochemical activity and surface morphology changes in particular, because most of the studies were simply aimed at improving the adhesion of CFs to their matrix materials [ 21 , 25 , 30 , 39 ]. However, in practice, CF may be strongly polarized if it is used as an electrochemical sensor or reinforcement for carbon fiber reinforced polymers (CFRPs) in a service environment with stray current densities [ 5 ].…”

Preparation of Boron Nitride-Coated Carbon Fibers and Synergistic Improvement of Thermal Conductivity in Their Polypropylene-Matrix Composites

“…Among these, CF has drawn more attention in composite design where anisotropic high thermal conductivity, large mechanical load transfer, and light weight are desirable. However, the inertness of the CF surface and the difference in its surface energetics with polymers play a key role in the integrity and properties of the final multicomponent system [12][13][14][15]. Therefore, the challenge addressed here is to enhance the interfacial adhesion between the matrix and the filler using the proper interfaces to obstruct the boundary phonon scattering while buffering the electrical conductivity of CFs for a better and safer performance in electronic units.…”