Strategies to Successfully Cross-Link Carbon Nanotubes

Gao

Comptes Rendus. Mécanique

et al. 2014

The mechanics of responsive fiber-network materials have been explored here by performing coarse-grained molecular dynamics simulations. Theoretical analysis based on a simple viscoelastic model is used to characterize the relationship between their microstructures and overall mechanical behaviors. The dynamic responses in stress and strain induced by externally tuned interfiber crosslinks are discussed. Our results here indicate the possibility of optimizing the dynamic performance of macroscopic network materials by tuning the crosslinks at the molecular level, and lay the groundwork for dynamic material design for structural and mechanical applications.

Section: Discussionmentioning

confidence: 99%

Mechanics of network materials with responsive crosslinks

Gao

Comptes Rendus. Mécanique

et al. 2014

“…The MWCNTs networks were prepared using FFS method according to [26]. An N, N dimethylformamide (DMF) solution was calibrated to certain pH (a measure of the acidity of the DMF solution).…”

Section: Preparation Of Mwcnts-oh Networkmentioning

confidence: 99%

“…This method is used to create an interlocking network that is simple and straightforward because it does not require the use of high-pressure processes or electron beams to fuse the tubes. The reaction conditions can be controlled by maintaining the tubes' temperature and dispersion until the suspension is ready to cast and produces a flexible network [26].…”

Section: Introductionmentioning

confidence: 99%

Fabrication and Characterization of Functionalized Multi-Wall Carbon Nanotubes Flexible Network Modified by a Layer of Polypyrrole Conductive Polymer and Metallic Nanoparticles

Taradh

Saleh

2022

NHC

Short Multi-Walled Carbon Nanotubes functionalized with OH group (MWCNTs-OH) were used to synthesize flexible MWCNTs networks. The MWCNTs suspension was synthesized using Benzoquinone (BQ) and N, N Dimethylformamide alcohol (DMF) in specific values and then deposited on filter paper by filtration from suspension (FFS) method. Polypyrrole (PPy) conductive polymer doped with metallic nanoparticles (MNPs) prepared using in-situ chemical polymerization method. To improve the properties of the MWCNTs networks, a coating layer of (PPy) conductive polymer, PPy:Ag nanoparticles, and PPy: Cu nanoparticles were applied to the network. The fabricated networks were characterized using an X-ray diffractometer (XRD), UV-Vis. spectrometer, and Atomic Force Microscope (AFM). XRD results revealed that the broadening for the (002) peak decreased after being coated with PPy and increased for the doped samples with MNPs, indicating on decrease in the crystalline size (MWCNTs/PPy) sample and increasing for doped ones with Ag and Cu MNPs. AFM images revealed that the surface roughness of the MWCNTs-OH network decreased after being coated with PPy, PPy: Ag, and PPy: Cu. With the help of AFM and XRD results, the CNTs contain 14 layers, while the inner and outer diameters were 18.2 nm and 27 nm receptivity. The UV-Vis. spectrum of MWCNTs showed several peaks, the highest in the 350 nm range. The coated of MWCNTs greatly affected the absorption spectrum, with many bands appearing between 300 to 450 nm and increasing the absorbance along the overall spectrum. For samples doped with Ag NPs and Cu NPs, a weak absorption peak of the plasmonic resonance frequency of the metallic nanoparticles. Analysis of Raman spectra shows that (ID/IG) ratios for all networks are less than one, which prove that the fabricated networks have few impurities and have good homogeneity. This work aimed to synthesize and characterize a flexible MWCNTs network and develop it by coated with a layer of conductive polymer and metallic nanoparticles for gas sensing application using quick and straightforward preparation methods.

“…There are several different classes of methods for successfully cross-linking CNTs. 13 10 Another method employs cyclo-addition reactions to break C C bonds in order to functionalize the sidewalls of the nanotubes. 14 In 2008, Zhang et al were the first to publish reports on the use of polymers for the cross-linking of carbon nanotubes.…”

Section: Introductionmentioning

confidence: 99%

High-Temperature Cross-Linking of Carbon Nanotube Multi-Yarn Using Polyvinylpyrrolidone as a Binding Agent

Misak¹,

Asmatulu²,

Whitman³

et al. 2015

j nanosci nanotechnol

Carbon nanotube (CNT) multi-yarn was cross-linked together at elevated temperatures using a poly- mer, with the intent of improving their strength and electrical conductivity. They were functionalized using an acid treatment and immersed in a bath of different concentrations (0.5%, 0.1%, and 0.2%) of polyvinylpyrrolidone (PVP). Then they were placed in an oven at various temperatures (180 °C, 200 °C, and 220 °C) in order to cause cross-linking among the carbon nanotube yarns. The phys- ical, chemical, electrical, and mechanical properties of the cross-linked yarns were investigated. The yarns cross-linked at higher temperatures and greater concentrations of PVP had a greater increase in linear mass density, indicating that the cross-linking process had worked as expected. Yarns that were cross-linked at lower temperatures had greater tensile strength and better spe- cific electrical conductivity. Those that were treated with a greater concentration of polymer had a greater ultimate tensile strength. All these results are encouraging first step, but still need further development if CNT yarn is to replace copper wire.