Efficient Dispersion of “Super-Growth” Single-Walled Carbon Nanotubes Using a Copolymer of Naphathalene Diimide and Poly(dimethylsiloxane)

Abstract

The dispersion of carbon nanotubes is a key issue for maximizing their performance in many applications. Here we describe the design and synthesis of an efficient dispersant for the so-called “super-growth” single-walled carbon nanotubes (SG-SWNTs) to provide a stable and homogeneous dispersion in typical organic solvents simply by sonication. The synthesized dispersant is a copolymer composed of a naphthalene diimide and poly(dimethylsiloxane), and the dispersions were characterized using visible absorption, Raman, AFM, and TGA measurements as well as molecular-mechanics simulations. It was found that the copolymer efficiently dissolves the SG-SWNTs in many solvents including methyl ethyl ketone, methyl isobutyl ketone, and toluene that are widely-used solvents in polymer/resin-related industrial areas.

Flexural behavior of 3Dpara-aramid/phenolic/nano (MWCNT) composites

“…39 It was claimed that a naphthalene diimide and poly(dimethylsiloxane) based dispersant was synthesized to enhance the agglomeration of the SWCNTs in the matrix. 40 It was reported that the bending modulus of the binary nanocomposite showed an improvement of about onethird compared to the neat composite. 41 In addition, the carbon ber surface characteristics were also found to have a signicant effect on the bending properties of the composite.…”

Solid-Phase Debundling of Single-Walled Carbon Nanotubes for the “Stock Solid” Delivery of Concentrated Nanotube Dispersions

“…Between the two approaches developed so far for preparing SWNTs dispersions, noncovalent functionalization is considered to be superior to the covalent one in terms of preserving the conjugated structure and intrinsic properties of SWNTs. Therefore, a number of researchers have concentrated on developing novel and efficient dispersants, including surfactants, − biomolecules, − aromatic compounds, − and polymers, ,, for noncovalent functionalization of SWNTs. On the other hand, the means employed to achieve noncovalent functionalization have been mostly limited to bath and probe type sonication. ,,− Although these liquid-phase sonication based techniques are sufficient for debundling and dispersing SWNTs in various solvents in the presence of dispersant, they suffer from either low concentration or low yield (<60 μg / mL or <15%, respectively) .…”

“…Therefore, a number of researchers have concentrated on developing novel and efficient dispersants, including surfactants, − biomolecules, − aromatic compounds, − and polymers, ,, for noncovalent functionalization of SWNTs. On the other hand, the means employed to achieve noncovalent functionalization have been mostly limited to bath and probe type sonication. ,,− Although these liquid-phase sonication based techniques are sufficient for debundling and dispersing SWNTs in various solvents in the presence of dispersant, they suffer from either low concentration or low yield (<60 μg / mL or <15%, respectively) . Furthermore, the presence of solvent may make the concentration less controllable and less precise.…”

“…Since no solvent was added, the milled powder can be stored as a “stock solid” and readily dispersed in water simply by shaking with hand prior to use, avoiding the sedimentation from “stock dispersion” . These are considered to be advantages of dry ball milling over wet process including bath and probe type sonication, shearing, and wet ball milling, in terms of long-term storage. ,,,− Furthermore, through the ball milling debundling combined with shake-assisted dispersing process, about 60% SWNTs were well dispersed in H 2 O. This value is much higher than that through sonication (mostly <30%) ,,, and vibration milling mentioned above (<6%) …”

Carbon nanotube/metal-sulfide composite flexible electrodes for high-performance quantum dot-sensitized solar cells and supercapacitors

“…Therefore, other CE materials, such as PbS, Cu 2 S, CoS, CoS/CuS, NiS, carbon, ZnO/metal sulfides, and Cu 2 S-reduced graphene oxide composites, have been inspected for their higher electrocatalytic activity towards the reduction of the polysulfide redox couple 14 15 16 17 18 19 20 21 . Carbon nanotubes (CNTs) are attractive candidates with high electrical conductivity, large surface area, and low density, making them candidates for applications in various fields, such as microelectronics, energy, and biotechnology 22 23 24 25 26 . Recently, multiwall carbon nanotubes (MWCNTs) were proposed as an efficient CE material in QDSSCs to suppress the charge transfer resistance at the CE/electrolyte interface and achieve higher efficiency (4.67%) than CuS CE (3.67%) 27 .…”