Recent Developments in Carbon Nanotubes-Reinforced Ceramic Matrix Composites: A Review on Dispersion and Densification Techniques

Abstract

Ceramic matrix composites (CMCs) are well-established composites applied on commercial, laboratory, and even industrial scales, including pottery for decoration, glass–ceramics-based light-emitting diodes (LEDs), commercial cooking utensils, high-temperature laboratory instruments, industrial catalytic reactors, and engine turbine blades. Despite the extensive applications of CMCs, researchers had to deal with their brittleness, low electrical conductivity, and low thermal properties. The use of carbon nanotubes (CNTs) as reinforcement is an effective and efficient method to tailor the ceramic structure at the nanoscale, which provides considerable practicability in the fabrication of highly functional CMC materials. This article provides a comprehensive review of CNTs-reinforced CMC materials (CNTs-CMCs). We critically examined the notable challenges during the synthesis of CNTs-CMCs. Five CNT dispersion processes were elucidated with a comparative study of the established research for the homogeneity distribution in the CMCs and the enhanced properties. We also discussed the effect of densification techniques on the properties of CNTs-CMCs. Additionally, we synopsized the outstanding microstructural and functional properties of CNTs in the CNTs-CMCs, namely stimulated ceramic crystallization, high thermal conductivity, bandgap reduction, and improved mechanical toughness. We also addressed the fundamental insights for the future technological maturation and advancement of CNTs-CMCs.

Improved Performance of Composite Bipolar Plates for PEMFC Modified by Homogeneously Dispersed Multi-Walled Carbon Nanotube Networks Prepared by In Situ Chemical Deposition

“…For I-CBPs, the flexural strength rose with low CNT content and decreased with high CNT content, and the best flexural strength was achieved under the condition that the mass fraction of MWCNTs was 2%, and its flexural strength could reach 50.24 MPa. MWCNTs as nano-fillers have a good strengthening effect on EG, and the surface-grown MWCNTs can not only make the contact points between graphite particles increase and make the graphite surface rougher [ 48 ] but also fills the pores of the matrix [ 49 ]. CNTs with the right content have a good strengthening effect on EG.…”

Tribological Properties of Blocky Composites with Carbon Nanotubes

“…It is common to prepare CNT ceramic matrix composites through powder processing, which typically requires two to three steps [114]. Figure 19 compares two-step and three-step powder processing.…”

“…Colloidal processing involves a variety of physical/chemical methods to disperse CNT with water/solvents, employing dispersion steps such as ultrasonication, magnetic stirring, and chemical oxidation to convert it into CNT nanofluids, which in turn are Colloidal processing involves a variety of physical/chemical methods to disperse CNT with water/solvents, employing dispersion steps such as ultrasonication, magnetic stirring, and chemical oxidation to convert it into CNT nanofluids, which in turn are added to ceramic powders and densified to obtain ceramic matrix composite products. Whereas the choice of CNT dispersant is limited [114] as it needs to fulfill the following sintering steps.…”

Zirconia-Based Ceramics Reinforced by Carbon Nanotubes: A Review with Emphasis on Mechanical Properties

“…Different processing routes have been proposed over the last few years for the preparation of CNT/ceramic-matrix composites, as comprehensively reviewed by Chan et al [50]. The techniques may greatly vary depending on the type of ceramic used, but, in general, a sintering step is always necessary to consolidate the final product.…”