Enhancement of the Electrical Conductivity and Interlaminar Shear Strength of CNT/GFRP Hierarchical Composite Using an Electrophoretic Deposition Technique.

Amin Haghbin,Gholamhossein Liaghat,Homayoun Hadavinia,Mohammad Pol,Amir Arabi

doi:10.3390/ma10101120

Abstract

In this work, an electrophoretic deposition (EPD) technique has been used for deposition of carbon nanotubes (CNTs) on the surface of glass fiber textures (GTs) to increase the volume conductivity and the interlaminar shear strength (ILSS) of CNT/glass fiber-reinforced polymers (GFRPs) composites. Comprehensive experimental studies have been conducted to establish the influence of electric field strength, CNT concentration in EPD suspension, surface quality of GTs, and process duration on the quality of deposited CNT layers. CNT deposition increased remarkably when the surface of glass fibers was treated with coupling agents. Deposition of CNTs was optimized by measuring CNT’s deposition mass and process current density diagrams. The effect of optimum field strength on CNT deposition mass is around 8.5 times, and the effect of optimum suspension concentration on deposition rate is around 5.5 times. In the optimum experimental setting, the current density values of EPD were bounded between 0.5 and 1 mA/cm2. Based on the cumulative deposition diagram, it was found that the first three minutes of EPD is the effective deposition time. Applying optimized EPD in composite fabrication of treated GTs caused a drastic improvement on the order of 108 times in the volume conductivity of the nanocomposite laminate in comparison with simple GTs specimens. Optimized CNT deposition also enhanced the ILSS of hierarchical nanocomposites by 42%.

Highlights

In hierarchical composites, nanoscale reinforcements are integrated with traditional composites to manipulate the interfacial or interphase properties between fibers and the polymer resin
When higher field strength and suspension concentration were used, agglomerated carbon nanotubes (CNTs) were deposited on the surface of glass fibers
Electrophoretic deposition of CNTs on the surface of glass fibers has been found to be a versatile method to incorporate a conductive layer between nonconductive glass fiber laminates

Summary

Introduction

Nanoscale reinforcements are integrated with traditional composites to manipulate the interfacial or interphase properties between fibers and the polymer resin. Reinforcing the traditional fiber-reinforced polymers (FRPs) with carbon nanotubes (CNTs) has shown many improvements in toughness, stiffness, strength, and electrical conductivity. Several experimental investigations [3,7,8], computational models [9,10], multi-scale material modeling [11,12,13], and other studies have shown the benefit of utilizing CNTs in polymers and FRPs to improve the mechanical/electrical performance of composite structures under various loading conditions. CNTs can increase the strength of glass fiber-reinforced polymer (GFRPs) laminates, especially their out-of-plane and shear loading capacities [14]. CNTs frequently below 2 wt % are dispersed in the polymer matrix using mechanical mixing techniques such as shear mixing, rolling, or ultrasonic dispersion

Methods

Results

Conclusion