Hybrid Composites Based on Carbon Fiber/Carbon Nanofilament Reinforcement.

Mehran Tehrani,Marwan Al-Haik,Ayoub Yari Boroujeni,Claudia Luhrs,Jonathan Phillips

doi:10.3390/ma7064182

Mehran Tehrani, Marwan Al-Haik + Show 3 more

Open Access

https://doi.org/10.3390/ma7064182

Copy DOI

Abstract

Carbon nanofilament and nanotubes (CNTs) have shown promise for enhancing the mechanical properties of fiber-reinforced composites (FRPs) and imparting multi-functionalities to them. While direct mixing of carbon nanofilaments with the polymer matrix in FRPs has several drawbacks, a high volume of uniform nanofilaments can be directly grown on fiber surfaces prior to composite fabrication. This study demonstrates the ability to create carbon nanofilaments on the surface of carbon fibers employing a synthesis method, graphitic structures by design (GSD), in which carbon structures are grown from fuel mixtures using nickel particles as the catalyst. The synthesis technique is proven feasible to grow nanofilament structures—from ethylene mixtures at 550 °C—on commercial polyacrylonitrile (PAN)-based carbon fibers. Raman spectroscopy and electron microscopy were employed to characterize the surface-grown carbon species. For comparison purposes, a catalytic chemical vapor deposition (CCVD) technique was also utilized to grow multiwall CNTs (MWCNTs) on carbon fiber yarns. The mechanical characterization showed that composites using the GSD-grown carbon nanofilaments outperform those using the CCVD-grown CNTs in terms of stiffness and tensile strength. The results suggest that further optimization of the GSD growth time, patterning and thermal shield coating of the carbon fibers is required to fully materialize the potential benefits of the GSD technique.

Highlights

Fiber-reinforced polymer plastics (FRPs) possess superior specific strengths and stiffness in comparison to other structural composites, such as metal or ceramic-reinforced composites
The nickel film should be fragmented into particles to grow carbon nanofilaments via graphitic structures by design (GSD); otherwise, it might lead to the growth of either graphene of graphite [18]
The surface modification of the carbon fiber through heat treatment, coating with SiO2 film in an attempt to prevent the fibers’ thermal degradation and growing carbon nanofilaments via GSD and chemical vapor deposition (CCVD) on the surface influence the mechanical properties of the composites based on these different fiber configurations

Summary

Introduction

Fiber-reinforced polymer plastics (FRPs) possess superior specific strengths and stiffness in comparison to other structural composites, such as metal or ceramic-reinforced composites. Multi-walled CNTs with smooth walls and low impurity content were grown on a carbon fiber cloth using plasma-enhanced chemical vapor deposition (PECVD) from a mixture of acetylene and ammonia [13] In this case, a cobalt colloid was utilized to achieve the good coverage of nanofibers on the carbon cloth. GSD could offer the opportunity to place CNTs in pre-designated locations (where the catalyst is pre-deposited), whereas utilizing the CCVD technique, CNTs grow everywhere This investigation sheds some light on the effect of the growth technique on the quasistatic mechanical properties of FRPs made out of a hybrid reinforcement that utilizes carbon nanofilaments grown on the surface of carbon fibers

Results and Discussion

Growing Carbon Nanofilament Using GSD

Microstructural and Mechanical Characterization

Conclusions