Role of Solvent Polarity on Dispersion Quality and Stability of Functionalized Carbon Nanotubes

Abstract

Dispersion of carbon nanotubes (CNT) in solvents and/or polymers is essential to reach the full potential of the CNTs in nanocomposite materials. Dispersion of CNTs is especially challenging due to the van-der-Waals attraction forces between the CNTs, which let them tend to re-bundle and/or re-aggregate. This paper presents a brief analysis of the quality and stability of functionalized multiwalled carbon nanotubes (fMWCNT) dispersion on polar solvents. A comparative study of functionalized CNT dispersion in water, methyl, and alcohol-based organic solvents has been carried out and the dispersion has been characterized by UV-VIS spectroscopy, electrochemical characterization such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Visual analysis of the dispersion has been investigated for up to 14 days to assess the dispersion’s stability. Based on the material characterization, it was observed that the degree of affinity fMWCNT with -COOH group highly depends on the polarity of the solvent, where the higher the polarity, the better the interaction of fMWCNT with solvents.

Plasmonic Nanofluids: Enhancing Photothermal Gradients toward Liquid Robots

“…On the contrary, polydispersity occurs in water, with a larger fraction of clusters around d ≈ 100 nm and a mean d ≈ 140 nm. The lower sizes obtained in water are attributed to its polar nature, which contributes to keeping particles separated as observed in other works . SAXS of a 0.025 wt % oil-based nanofluid further indicates that the average particles size composing the larger agglomerate is around D saxs ≈ 28 nm (Figure S1a), in agreement with the SEM estimates of the dry powder.…”

“…The lower sizes obtained in water are attributed to its polar nature, which contributes to keeping particles separated as observed in other works. 49 SAXS of a 0.025 wt % oil-based nanofluid further indicates that the average particles size composing the larger agglomerate is around D saxs ≈ 28 nm (Figure S1a), in agreement with the SEM estimates of the dry powder. It can be concluded that in the oil-based nanofluid, there are TiN nanoclusters with a dimension of around 300 nm, composed of NPs with a diameter of around 30 nm.…”

Characterization of Microstructured Multiwalled Carbon Nanotube/Polydimethylsiloxane Composites for Piezoresistive Sensing Applications

“…[17,[25][26][27] However, to homogeneously disperse the MWCNT, researchers often resort to aggressive polar solvents such as toluene, methanol, and dimethylformamide because they grant a faster and longerlasting dispersion of the nanotubes. [28] In an effort to contradict this tendency, Rajendram et al conducted a study using different solvents, namely water, ethanol, 2-propanol (IPA), and toluene to analyze their influence on the dispersion of MWCNT. [28] According to their findings, the affinity of functionalized MWCNT is higher for water, followed by ethanol, IPA, and finally, toluene.…”

A Binder‐Free and Flexible VOPO4/CNT Film as Cathode for Aqueous Rechargeable Zn‐Metal Battery

“…[29][30][31][32] However, it is worth noting that the poor dispersion of CNT in various solvents causes inhomogeneous mixing with the active material. [29,33,34] To overcome this issue, in this work, CNT is chemically functionalized to create oxygencontaining surface functional groups prior to the in-situ mixing in the aqueous vanadium precursor solution. The water contact angle measurements on the pristine CNT (pCNT, Figure S1a, Supporting Information) and fCNT samples (Figure S1b, Supporting Information) prove that the latter possesses more hydrophilicity than the former.…”

“…For instance, pCNT displays a high water contact angle of 94.1°, whereas the same is extremely low in fCNT due to its excellent wetting behavior, suggesting the importance of the pre-functionalization of CNT. [34] The attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) measurement of fCNT (Figure S2b, Supporting Information) shows the appearance of the broad peaks at 3050 to 3500, 1630, and 1020 cm −1 related to the presence of the different oxygen functionalities (-OH, -COOH, -C=O, and -C-O) that contribute to its hydrophilic nature and improved dispersion in the aqueous medium (Figure S2a, Supporting Information). [35,36] During the synthesis of VP/fCNT-P composite, these functional groups on fCNTs can electrostatically interact with the VO 2 + ions present in the reaction solution and serve as the anchoring sites for the growth of the VP nanosheets.…”