Cu–MWCNT Composite Films Fabricated by Electrodeposition

Kirihata

Ueda

et al. 2017

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Copper/single-walled carbon nanotube (SWCNT) composites were fabricated by electrodeposition using a freestanding SWCNT film as a template. The SWCNT films were directly electrodeposited to form copper/SWCNT composites. An acidic copper sulfate bath was employed as a basic plating bath, and the effects of additives to the basic bath on the morphologies of copper deposits were examined. Poly(ethylene glycol), chloride ions (Cl -), bis(3-sulfopropyl)disulfide (SPS), and Janus green B (JGB) were added individually or in combination as additives. Electrodeposition of copper occurred only on the surface of the SWCNT film when using the basic plating bath without additives. In contrast, copper was deposited not only on the surface but also in the interior of the SWCNT film when using the plating baths containing at least PEG and Cl -, resulting in copper/SWCNT composites. Electrodeposition of copper inside the SWCNT film was accelerated dramatically when all four additives (PEG, Cl -, SPS, and JGB) were added to the basic bath. This novel fabrication method of copper/CNT composites using CNT films as templates can be applied to the fabrication of various types of metal/CNT composites. Carbon nanotubes (CNTs) exhibit high thermal conductivity 1-6 and high current-carrying capacity (ampacity) 7 as well as excellent mechanical characteristics.8-10 Therefore, the development of practical applications of CNTs is an active area of research. Copper/CNT composites are promising materials, especially in the electronics field, and many fabrication methods, such as spark plasma sintering, [19][20][21][22][23] have been reported. The CNT composite plating has advantages, such as the uniform distribution of CNTs in metal matrices derived from a homogeneous dispersion of CNTs in plating baths, which results in little damage to CNTs due to dispersant addition at room temperature instead of direct grafting of hydrophilic groups that makes CNTs hydrophilic. Copper/CNT composite films possess excellent tribological 24,25 and field emission 26,27 properties. However, in general, the CNT content in electrodeposited composites is low (ca. 0.5 mass% 22 ), which could lead to insufficient thermal conductivity. 22 Therefore, other methods to obtain copper/CNT composites with a greater CNT content are needed.Recently, a freestanding, thin CNT film, 28,29 made from an aggregate of CNTs and so-called "bucky paper," has attracted considerable attention for its application as high efficiency filters, 30,31 displays, 32 lithium-ion battery anodes, 33 and supercapacitors. 34,35 Furthermore, composites using freestanding CNT films as flexible scaffolds for active materials have been investigated particularly intensively for their application to rechargeable batteries. [36][37][38][39][40][41][42][43][44][45][46][47][48] Electrodeposition of copper inside the freestanding CNT film was expected to be an effective method for forming copper/CNT composites with greater CNT content. However, few studies on direct electrodeposition not limited to copper o...

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confidence: 99%

Fabrication of Copper/Single-Walled Carbon Nanotube Composites by Electrodeposition Using Free-Standing Nanotube Film

Kirihata

Ueda

et al. 2017

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“…We have also examined the electrodeposition of metal/CNT composite films and reported the fabrication and characteristics of dense Cu/CNT composite films. 23 Consequently, a combination of the 3DC1 technology and the Cu/CNT composite plating technology is expected to produce a practical 3DC/CNT composite film material.In this study, the fabrication of 3DC/CNT composite films by one-step electrodeposition and the resulting microstructure of the 3DC/CNT composite films were investigated. * Electrochemical Society Member.…”

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confidence: 99%

mentioning

confidence: 99%

Fabrication of Three-Dimensional (3D) Copper/Carbon Nanotube Composite Film by One-Step Electrodeposition

Ozawa

Shimizu

2016

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A three-dimensional (3D) composite film containing copper nanostructures and carbon nanotubes (3DC/CNT composite film) was fabricated by one-step electrodeposition. The 3DC/CNT composite film was formed under galvanostatic conditions using a copper sulfate bath containing CNTs and polyacrylic acid which acts as both a 3DC-forming and a CNT-dispersing agent. The composite film consists of thin copper sheets with thicknesses of ca. 70-80 nm and CNTs, with large interior spaces between sheets. The CNTs were homogeneously distributed inside the composite film and were fixed by the copper sheets where CNTs pierce the copper sheets. The CNT content in the composite films increased with the CNT concentration of the plating bath. The 3DC film without CNTs did not maintain its 3D spaces when the film thickness was increased due to insufficient structural strength, whereas the 3DC/CNT composite film maintained the 3D spaces despite an increase in film thickness, which suggests that the CNTs reinforce the film to maintain the 3D spaces. Three-dimensional (3D) nanostructured metal architectures typically exhibit large specific surface areas and high electrical conductivity; therefore, their application as electrodes in functional devices such as supercapacitors, 1 fuel cells 2 and batteries 3 have been widely researched. For these potential applications, the use of 3D copper nanostructured architectures 4-8 is most attractive. However, although 3D copper nanostructured architectures are very effective to improve electrode functions, their manufacture requires many steps and is therefore complex. Our group has previously developed a very straightforward method for the fabrication of 3D copper nanostructured architectures by electrodeposition, in which an organic additive is simply added to an electrodeposition bath.9 This process for the preparation of 3D copper nanostructured architecture films by onestep electrodeposition (the resulting products henceforth being designated as 3DC1 film) is expected to be used as a practical method for the fabrication of various components, such as current collectors for tin-based lithium-ion battery anodes.10 However, the 3DC1 film consists of very thin (30-50 nm) copper sheets; therefore, its structural strength is low, which results in deformation of the 3D structure when a slight physical force is applied.In contrast, carbon nanotubes (CNTs) 11,12 have excellent mechanical characteristics, 13-15 such as high tensile strength and high elastic modulus, in addition to high thermal [16][17][18] and electrical conductivity. 19,20 Research into CNT composites such as metal/CNT composites has thus been actively pursued.21,22 A 3D-copper nanostructured architecture containing CNTs (3DC/CNT composite) is thus considered to be an attractive copper-based 3D composite material that would have sufficient structural strength due to the reinforcement effect of the CNTs. If a 3DC/CNT composite could be fabricated by a simple method, then the 3DC/CNT composite materials would be expected to be used for ...

“…[19][20][21] This method has several advantages. For instance, Cu/CNT composites can be formed at ambient temperature and atmospheric pressure.…”

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confidence: 99%

Fabrication of Copper/Multiwalled Carbon Nanotube Composites Containing Different Sized Nanotubes by Electroless Deposition

Osaki

2014

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Cu/multiwalled carbon nanotube (MWCNT) composites containing two different sized MWCNTs were fabricated using an electroless deposition technique in aqueous solution. In order to disperse the MWCNTs in the solution, an anionic dispersant of sodium dodecyl sulfate (SDS) and a polymeric dispersant of hydroxypropyl cellulose (HPC) were used. The dispersibility of the MWCNTs in solution was evaluated by measuring the particle size distribution. The zeta potential for the MWCNTs was also evaluated to examine the dispersibility. Uniform Cu/MWCNT composites containing the two different sized MWCNTs were fabricated through the electroless copper deposition process from a solution containing copper ions, a complexing agent, a reducing agent, and two dispersants, SDS and HPC, in addition to the two different sized MWCNTs.