Tailoring Interfacial Properties by Controlling Carbon Nanotube Coating Thickness on Glass Fibers Using Electrophoretic Deposition

Abstract

The electrophoretic deposition (EPD) method was used to deposit polyethylenimine (PEI) functionalized multiwall carbon nanotube (CNT) films onto the surface of individual S-2 glass fibers. By varying the processing parameters of EPD following Hamaker's equation, the thickness of the CNT film was controlled over a wide range from 200 nm to 2 μm. The films exhibited low electrical resistance, providing evidence of coating uniformity and consolidation. The effect of the CNT coating on fiber matrix interfacial properties was investigated through microdroplet experiments. Changes in interfacial properties due to application of CNT coatings onto the fiber surface with and without a CNT-modified matrix were studied. A glass fiber with a 2 μm thick CNT coating and the unmodified epoxy matrix showed the highest increase (58%) in interfacial shear strength (IFSS) compared to the baseline. The increase in the IFSS was proportional to CNT film thickness. Failure analysis of the microdroplet specimens indicated higher IFSS was related to fracture morphologies with higher levels of surface roughness. EPD enables the thickness of the CNT coating to be adjusted, facilitating control of fiber/matrix interfacial resistivity. The electrical sensitivity provides the opportunity to fabricate a new class of sizing with tailored interfacial properties and the ability to detect damage initiation.

Quantification of carbon nanotube dispersion and its correlation with mechanical and thermal properties of epoxy nanocomposites

“…This results in an extra energy of fracture and enhancement in the interfacial toughness . Localized inelastic matrix deformation, filler debonding and pull‐out, crack immobilization and deflection, filler deformation or breaking at crack tip are some other mechanisms responsible for enhanced properties of nanocomposites …”

Smart cord-rubber composites with integrated sensing capabilities by localised carbon nanotubes using a simple swelling and infusion method

“…potential of the developed CNT infused glass cord as smart reinforcements for rubber products, with added interfacial damage and strain sensing capabilities, efforts were made to evaluate the effect of CNT infusion on adhesion between cord and rubber.Several micromechanical characterisations can be used to quantitatively evaluate the interfacial shear strength (IFSS) between a reinforcing fibre and its surrounding matrix, including single fibre pull-out and fibre fragmentation tests[34].Figure 8apresents the single cord pull-out test results of various CNT infused glass cord-rubber and as-received glass cord-rubber composites swollen in various solvents without the presence of CNTs (acetone, NMP, and DMF, respectively) for 1 h under the same conditions before embedded into the HNBR matrix. It can be seen that no significant change in IFSS values was observed, within typical experimental error[16,19,35]. Fractographic analysis (Figure 8band 8c) of fracture surfaces after pull-out indicated a change from failure mode of the elastomeric coating/HNBR interface failure to failure at the elastomeric coating/glass fibre interface, indicating a toughening of the elastomeric coating/HNBR interphase due to the presence of CNTs.…”

“…Other techniques used to develop CNT-coated smart textile materials include electrophoretic deposition (EPD) [15,16], chemical vapour deposition (CVD) [17,18], electrospray [19] and spray coating [20,21]. For instance, hierarchical CNT-GF with preferred CNT alignment was achieved by CVD and employed for in-situ SHM of glass fibre reinforced composites during flexural testing [11].…”

Design of Electrically Conductive Structural Composites by Modulating Aligned CVD-Grown Carbon Nanotube Length on Glass Fibers

“…[21][22][23][24][25][26][27][28] Several techniques have been reported to develop CNTs-coated GF, which include the solution coating methods such as dip coating, spray coating and electrophoretic deposition, and chemical vapor deposition (CVD). [27][28][29][30][31][32][33][34] For the solution deposition techniques, it is a prerequisite to have homogeneous and stable CNT suspension. In general, some chemical surfactants or polymers are employed during CNT dispersion process due to their inert surface characteristics.…”