Enhanced Surface Energetics of CNT-Grafted Carbon Fibers for Superior Electrical and Mechanical Properties in CFRPs

Abstract

Surface enhancement of components is vital for achieving superior properties in a composite system. In this study, carbon nanotubes (CNTs) were grown on carbon fiber (CF) substrates to improve the surface area and, in turn, increase the adhesion between epoxy-resin and CFs. Nickel (Ni) was used as the catalyst in CNT growth, and was coated on CF sheets via the electroplating method. Surface energetics of CNT-grown CFs and their work of adhesion with epoxy resin were measured. SEM and TEM were used to analyze the morphology of the samples. After the optimization of surface energetics by catalyst weight ratio (15 wt.% Ni), CF-reinforced plastic (CFRP) samples were prepared using the hand lay-up method. To validate the effect of chemical vapor deposition (CVD)-grown CNTs on CFRP properties, samples were also prepared where CNT powder was added to epoxy prior to reinforcement with Ni-coated CFs. CFRP specimens were tested to determine their electrical resistivity, flexural strength, and ductility index. The electrical resistivity of CNT-grown CFRP was found to be about 9 and 2.3 times lower than those of as-received CFRP and CNT-added Ni-CFRP, respectively. Flexural strength of CNT-grown Ni-CFRP was enhanced by 52.9% of that of as-received CFRP. Interestingly, the ductility index in CNT-grown Ni-CFRP was 40% lower than that of CNT-added Ni-CFRP. This was attributed to the tip-growth formation of CNTs and the breakage of Ni coating.

A review on carbon fiber-reinforced hierarchical composites: mechanical performance, manufacturing process, structural applications and allied challenges

“…The global market of CFRP is projected to reach $ 32 billion by 2025 [ 10 ]. CFRP consists of two constituents; a polymer matrix, either thermoplastic or thermoset, and carbon fiber (CF) as reinforcement [ 11 ]. In between the two constituents lies a three-dimensional interphase region having discrete characteristics.…”

Hybrid Polymer Composites Used in the Arms Industry: A Review

“…For the composite reinforced with the Ni-CNT-modified carbon fabric, the flexural strength increased by 52.9% compared to the reference sample. The ductility index was 40% lower than that of the composite with dispersed CNTs [ 57 ]. Nasser et al also deposited ZnO nanoparticles and wires on carbon fibers that were pre-functionalized with 70% nitric acid.…”

Mechanical properties of carbon‐fiber‐reinforced epoxy composites modified by carbon micro‐ and nanofillers

“…Some are searching for treatment techniques and manufacturing technologies providing better binder-to-fiber adhesion. [3][4][5] The others try to develop tougher epoxies. [6,7] One of the approaches allowing to improve mechanical properties of carbonfiber-reinforced polymers is associated with addition of micro-and nanoadditives to the binder.…”