Copper-Encapsulated Vertically Aligned Carbon Nanotube Arrays

Abstract

A new procedure is described for the fabrication of vertically aligned carbon nanotubes (VACNTs) that are decorated, and even completely encapsulated, by a dense network of copper nanoparticles. The process involves the conformal deposition of pyrolytic carbon (Py-C) to stabilize the aligned carbon-nanotube structure during processing. The stabilized arrays are mildly functionalized using oxygen plasma treatment to improve wettability, and they are then infiltrated with an aqueous, supersaturated Cu salt solution. Once dried, the salt forms a stabilizing crystal network throughout the array. After calcination and H2 reduction, Cu nanoparticles are left decorating the CNT surfaces. Studies were carried out to determine the optimal processing parameters to maximize Cu content in the composite. These included the duration of Py-C deposition and system process pressure as well as the implementation of subsequent and multiple Cu salt solution infiltrations. The optimized procedure yielded a nanoscale hybrid material where the anisotropic alignment from the VACNT array was preserved, and the mass of the stabilized arrays was increased by over 24-fold because of the addition of Cu. The procedure has been adapted for other Cu salts and can also be used for other metal salts altogether, including Ni, Co, Fe, and Ag. The resulting composite is ideally suited for application in thermal management devices because of its low density, mechanical integrity, and potentially high thermal conductivity. Additionally, further processing of the material via pressing and sintering can yield consolidated, dense bulk composites.

Hydrothermal Coating of Patterned Carbon Nanotube Forest for Structured Lithium‐Ion Battery Electrodes

“…First, a catalyst layer (10 nm Al 2 O 3 -1 nm Fe) is patterned using UVlithography (see the Experimental Section, Figure 1B1). From Small 2019, 15,1901201 this catalyst layer, VACNTs are grown using a thermal chemical vapor deposition (CVD) protocol (see the Experimental Section, Figure 1B2). This structure is then microcontact transfer printed onto a conductive layer on a glass substrate, termed as PCP film, composed of poly(vinylidene fluoride) (PVDF) and conductive additives (CNTs and phenyl C61 butyric acid methyl ester (PCBM)), following a recipe previously reported [21] ( Figure 1B3).…”

“…This can, for instance, be achieved by vertically aligned carbon nanotube (VACNT) “forests,” which are interesting conductive backbones for battery electrodes as they are electrochemically stable and provide a direct electrical wiring perpendicular to the current collectors . In addition, techniques are available to organize CNTs in high aspect ratio structures and to shape them in various forms, which allows to create, for instance, thick Si LIB anodes and flexible batteries …”

“…This can, for instance, be achieved by vertically aligned carbon nanotube (VACNT) "forests," which are interesting conductive backbones for battery electrodes as they are electrochemically stable and provide a direct electrical wiring perpendicular to the current collectors. [12,13] In addition, techniques are available to organize CNTs in high aspect ratio structures [12][13][14][15][16][17][18] and to shape them in various forms, [19][20][21] which allows to create, for instance, thick Si LIB anodes [7] and flexible batteries. [22][23][24][25] While the above advances are impressive, the current coating methods for VACNT forests are mainly based on gas phase processes (e.g., chemical vapor deposition of Si) in order not to damage these fragile structures, [18] which limits the battery chemistries that can be used.…”

A Review on Synthesis of CNTs and its Application in Conductive Paints

“…After drying, the salt forms a stabilizing crystal network throughout the array. The calcination and H 2 reduction, leads to deposition of Cu nanoparticles on the CNT surfaces [21].…”

Self-sensing carbon nanotube composites

“…This has stimulated the development and improvement of carbon nanotube-based multifunctional composites for enhancing mechanical properties like fracture toughness [4][5][6][7], vibration damping [8][9][10], fatigue life [11,12] along with nonstructural applications such as sensing [13,14], actuation [15,16], electromagnetic interference shielding [17,18], heat transfer [19], and energy storage and harvesting [20,21]. This has stimulated the development and improvement of carbon nanotube-based multifunctional composites for enhancing mechanical properties like fracture toughness [4][5][6][7], vibration damping [8][9][10], fatigue life [11,12] along with nonstructural applications such as sensing [13,14], actuation [15,16], electromagnetic interference shielding [17,18], heat transfer [19], and energy storage and harvesting [20,21].…”