Comparative Measures of Single-Wall Carbon Nanotube Dispersion

Size exclusion chromatography (SEC) is shown to be an effective method to characterize single-wall carbon nanotube (SWNT) dispersions. SEC separates nanotube dispersions by size, and an on-line viscosity detector gives intrinsic viscosity as a function of hydrodynamic size, as is determined by universal calibration. The scaling contains information about the shape of the dispersed particles. This characterization method was tested on three representative dispersions, octadecylamine functionalization (SWNT-ODA) in tetrahydrofuran (THF), butyl group functionalization (SWNT-butyl) in THF, and DNA wrapping (SWNT/DNA) in aqueous solution. Significant differences between the dispersions were found. Small-angle neutron scattering (SANS) and atomic force microscopy (AFM) produced results consistent with the SEC method.

show abstract

“…13 Additional measurements of SWNT dispersion have recently been made on nanotube dispersions in a solid matrix. 33 SWNT/ …”

Section: Resultsmentioning

confidence: 99%

Measurement of Single-Wall Nanotube Dispersion by Size Exclusion Chromatography

et al. 2007

View full text Add to dashboard Cite

show abstract

“…Physical surface modification is the noncovalent stabilization of CNTs by interaction with certain solvents, such as surfactants, polymers, and biomolecules. [15][16][17] For instance, sodium dodecylbenzene sulfonate was used as surfactant to assist the dispersion of CNTs. [15] A major drawback of both chemical and physical surface modifications is that impurity is often introduced into the CNT solution, and such impurity which is difficult to remove in further processes or applications.…”

Section: Doi: 101002/adma201104337mentioning

confidence: 99%

Hydrogen Passivation Induced Dispersion of Multi‐Walled Carbon Nanotubes

Yang

Pan

et al. 2012

Advanced Materials

View full text Add to dashboard Cite

show abstract

“…Four different methods using small-angle neutron scattering, near-infrared fluorescence measurement, optical absorption spectroscopy, and resonant Raman scattering were applied to determine the dispersion of DNA-wrapped single-walled carbon nanotubes (SWNT) in poly(acrylic acid) [25]. The morphology of dispersed SWNT was determined by light scattering [12] and the length and the diameter of multi-walled carbon nanotubes (MWNT) suspended in an aqueous solution were determined by analysis of the images taken by field emission gun scanning microscope [15].…”

Section: Introductionmentioning

confidence: 99%

Relationship between dispersion metric and properties of PMMA/SWNT nanocomposites

Kashiwagi

Fagan

Douglas

et al. 2007

Polymer

169

113

View full text Add to dashboard Cite

Particle spatial dispersion is a crucial characteristic of polymer composite materials and this property is recognized as especially important in nanocomposite materials due to the general tendency of nanoparticles to aggregate under processing conditions. We introduce dispersion metrics along with a specified dispersion scale over which material homogeneity is measured and consider how the dispersion metrics correlate quantitatively with the variation of basic nanocomposite properties. We then address the general problem of quantifying nanoparticle spatial dispersion in model nanocomposites of single wall carbon nanotubes (SWNT) dispersed in poly(methyl methacrylate) (PMMA) at a fixed SWNT concentration of 0.5 % using a 'coagulation' fabrication method. Two methods are utilized to measure dispersion, UV-Vis spectroscopy and optical confocal microscopy. Quantitative spatial dispersion levels were obtained through image analysis to obtain a 'relative dispersion index' (RDI) representing the uniformity of the dispersion of SWNTs in the samples and through absorbance. We find that the storage modulus, electrical conductivity, and flammability containing the same amount of SWNTs, the relationships between the quantified dispersion levels and physical properties show about four orders of magnitude variation in storage modulus, almost eight orders of magnitude variation in electric conductivity, and about 70 % reduction in peak mass loss rate at the highest dispersion level used in this study. The observation of such a profound effect of SWNT dispersion indicates the need for objective dispersion metrics for correlating and understanding how the properties of nanocomposites are determined by the concentration, shape and size of the nanotubes. conditions. We introduce dispersion metrics along with a specified dispersion scale over which material homogeneity is measured and consider how the dispersion metrics correlate quantitatively with the variation of basic nanocomposite properties. We then address the general problem of quantifying nanoparticle spatial dispersion in model nanocomposites of single wall carbon nanotubes (SWNT) dispersed in poly(methyl methacrylate) (PMMA) at a fixed SWNT concentration of 0.5 % using a 'coagulation' fabrication method. Two methods are utilized to measure dispersion, UV-Vis spectroscopy and optical confocal microscopy. Quantitative spatial dispersion levels were obtained through image analysis to obtain a 'relative dispersion index ' (RDI) representing the uniformity of the dispersion of SWNTs in the samples and through absorbance. We find that the storage modulus, electrical conductivity, and flammability † This was carried out by the National Institute of Standards and Technology (NIST), an agency of the US Government and is not subject to copyright in the US. ‡ Correspondence to: T. Kashiwagi (E-mail: takashi.kashiwagi@nist.gov) 1 property of the nanocomposites correlates well with the RDI. For the nanocomposites containing the same amount of SWNTs, the relationships betw...

show abstract

Comparative Measures of Single-Wall Carbon Nanotube Dispersion

Cited by 89 publications

References 26 publications

Measurement of Single-Wall Nanotube Dispersion by Size Exclusion Chromatography

Measurement of Single-Wall Nanotube Dispersion by Size Exclusion Chromatography

Hydrogen Passivation Induced Dispersion of Multi‐Walled Carbon Nanotubes

Relationship between dispersion metric and properties of PMMA/SWNT nanocomposites

Contact Info

Product

Resources

About