Dry‐Processable Carbon Nanotubes for Functional Devices and Composites

Abstract

Assembly of carbon nanotubes (CNTs) in effective and productive ways is of vital importance to their application. Recent progress in synthesis of CNTs has inspired new strategies for utilizing the unique physiochemical properties of CNTs in macroscale materials and devices. Assembling CNTs by dry processes (e.g., directly collecting CNTs in the form of freestanding films followed by pressing, stretching, and multilayer stacking instead of dispersing them in solution) not only considerably simplifies the processes but also avoids structural damage to the CNTs. Various dry-processable CNTs are reviewed, focusing on their synthesis, properties, and applications. The synthesis techniques are organized in terms of aggregative morphologies and microstructure control of CNTs. Important applications such as functional thin-film devices, strong CNT films, and composites are included. The opportunities and challenges in the synthesis techniques and fabrication of advanced composites and devices are discussed.

A silicon-impregnated carbon nanotube mat as a lithium-ion cell anode

“…CNTs can also be used as conductive additives; they exhibit excellent axial electric conductivity on the order of hundreds of S cm -1 depending on their configuration (i.e., aligned CNT mats, CNT powders, surface functionalized CNTs, etc.) [20][21][22] and when arranged into a mat configuration as shown in Figure 1.9 and Figure 1.10 [23,24] , their through-plane conductivity is on the same order as that of carbon black [25] .…”

Key factors limiting carbon nanotube strength: Structural characterization and mechanical properties of multi-walled carbon nanotubes

“…The structural defect densities of the MWCNTs, namely the number of the defects per unit of MWCNT length were quantified by measuring the number of the structural defects in 3-5 TEM 2 For more than two decades, many researchers have focused on carbon nanotubes (CNTs) which have remarkable values for their Young's modulus, tensile strength (Peng, et al, 2008), electrical/thermal conductivity Lorents, 1995, Ebbesen, et al, 1996) and negative thermal expansion coefficient (Yoshida, 2000, Shirasu, et al, 2015, motivating their use in composites as a fibrous reinforcing agent. Recently, continuous multi-walled CNT (MWCNT) yarns and sheets, which are prepared by directly drawing MWCNTs from spinnable MWCNT arrays, have been developed (Zhang, et al, 2004(Zhang, et al, , 2005 and new processing methods utilizing MWCNT yarns and sheets have emerged as means of producing preforms and composites with higher MWCNT volume fractions (Di, et al, 2014). The Young's modulus and strength of CNTs are well known to depend critically on the structure (e.g.…”

A new approach to fabricate carbon fiber reinforced polymer with roller pre‐stretching method and characterization of their mechanical properties

“…Furthermore, there are several studies conducted to increase the strength properties of the composite materials by increasing fibers linearity . Di et al investigated the stretching effect of mechanical properties on large‐scale carbon nanotube (CNT) films where CNTs were randomly aligned. The tensile strength increased to 390, 508, and 668 MPa, represented 90%, 148%, and 226% improvements, after stretched 30%, 35%, and 40%, respectively.…”