Effect of Graphene Nanowall Size on the Interfacial Strength of Carbon Fiber Reinforced Composites

Abstract

Graphene nanowalls (GNWs) with different sizes (i.e., length and height) were grown directly on the surface of individual carbon fibers (CFs) using a radio frequency plasma-enhanced chemical vapor deposition (RF-PECVD) technique. The size was controlled by varying the deposition time. The GNW-modified CFs were embedded into epoxy resin matrix to prepare a series of carbon-fiber-reinforced composites (CFRCs). The results indicated that GNWs were remarkably effective in improving the interfacial shear strength (IFSS) and interlaminar shear strength (ILSS) of the carbon-fiber-reinforced composites. The enhancement effect on the strength strongly depended on the size of GNWs. It increased with the increase in the GNWs’ size and reached the maximum upon the incorporation of GNWs that were grown for 45 min. Noticeable increases of 222.8% and 41.1% were observed in IFSS and ILSS, respectively. The enhancement mechanism was revealed by means of scanning electron microscope (SEM) fractography analysis. However, further increase of GNW size led to no more improvement in the shear strength. It could result from the increased defect concentration and wrinkle size in the GNWs, which deteriorated the strength.

Multifunctional Structural Supercapacitor Based on Urea-Activated Graphene Nanoflakes Directly Grown on Carbon Fiber Electrodes

“…Graphene nanoflakes (GNFs) are three-dimensional (3D) networks of vertically oriented multiple graphene layers, also met with names of graphene nanopetals and carbon or graphene nanowalls. Recently, GNFs directly grown on carbon fibers (denoted here as gCF ), by a catalyst-free radio frequency plasma-enhanced chemical vapor deposition (rf-PECVD), − have been demonstrated as a novel interface for improving the interfacial shear strength (IFSS) between the carbon fiber and the epoxy, with a maximum increase in IFSS of ∼118.7% without degrading the tensile strength of the underneath CF . Most lately, we demonstrated that radially aligned graphene nanoflakes (GNFs), grown by microwave PECVD within a few minutes, not only improve the interfacial shear strength (IFSS) by 101.5% but also lead to a remarkable 28% enhancement in the tensile strength of the hybrid fibers as observed via single-fiber tensile strength tests.…”

Establishment of Silane/GO Multistage Hybrid Interface Layer to Improve Interfacial and Mechanical Properties of Carbon Fiber Reinforced Poly (phthalazinone ether ketone) Thermoplastic Composites

“…Therefore, considerable studies have been concentrating on the surface treatments of CF to heighten the interfacial bonding of CFRTPs [ 9 , 10 , 11 ]. Plasma treatment [ 12 ], high-energy irradiation [ 13 ], sizing coatings [ 14 , 15 ], chemical grafting [ 16 ] techniques, etc., bring forth ways and means to settle the weak interface adhesion of CFRTP sectors.…”

Radially Grown Graphene Nanoflakes on Carbon Fibers as Reinforcing Interface for Polymer Composites

“…GNFs have received significant attention over recent years due to their conductive, porous morphology, and electron rich edges, which make them well suited for a variety of fields including electron field emission, blackbody antireflective coatings, electrodes for sensing, − and energy conversion and storage (electrodes for fuel cells, , batteries supercapacitors, − and solar cells , ). However, their use as a nano-reinforcement interface is an almost unexplored terrain with only limited work reported so far − on radio-frequency plasma enhanced chemical vapor deposited (rf-PECVD) GNFs on CFs. Furthermore, there are no studies that combine electrical, electrochemical, and mechanical properties to assess the potential for multifunctionality of the hybrid GNFs/CF fibers on structural composite applications.…”