Ms. Theresa G. Hedderman Profile

Theresa G. Hedderman

at Technological Univ Dublin

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Publications (6)

Proceedings Article | 3 June 2005 Paper

Fluorescence concentration studies of HiPco SWNTs and semi-conjugated polymers

S. Keogh, T. Hedderman, E. Gregan, G. Farrell, P. Lynch, G. Chambers, F. Lyng, H. Byrne

Proceedings Volume 5826, (2005) https://doi.org/10.1117/12.605060

KEYWORDS: Polymers, Composites, Single walled carbon nanotubes, Luminescence, Carbon nanotubes, Fluorescence spectroscopy, Spectroscopy, Raman spectroscopy, Absorption, Molecules

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Proceedings Article | 3 June 2005 Paper

Spectroscopic analysis of the interaction of SWNT with simple organic molecules

Theresa Hedderman, Sinead Keogh, Gordon Chambers, Hugh Byrne

Proceedings Volume 5826, (2005) https://doi.org/10.1117/12.601451

KEYWORDS: Single walled carbon nanotubes, Composites, Molecules, Luminescence, Raman spectroscopy, Polymers, Molecular interactions, Molecular spectroscopy, Solids, Spectroscopy

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This paper shows the solublisation and de-bundling of SWNT with an aim to obtaining individual SWNT. By achieving this goal their theoretically proposed properties can be verified and their industrial potential realised. It is well documented that Single Wall Carbon Nanotubes (SWNTs) show varying degrees of solubility in a number of organic solvents. Solubility of SWNTs in toluene was found to be negligible. With toluene having such a poor affinity for SWNT it is clear that the solvent interaction with the SWNT is negligible. Therefore toluene is an ideal candidate for monitoring the improvements in the solubility of the SWNTs as a result of interaction with dye molecules such as terphenyl and anthracene. The suspensions formed are stable for periods greater than thirty-six months. Spectroscopic analysis clearly shows interaction and de-bundling of SWNT on addition of the dye molecules. The fluorescence of the dye molecules is quenched on interaction with SWNTs and in the case of terphenyl, the spectrum is red shifted which gives further support to the notion of interaction. With the quenching in fluorescence of the dye molecules signifying interaction, a large range of concentrations were studied in order to quantify the degree of interaction between the SWNT and dye molecules. It was found at high concentrations such as 1 x 10^-3 M, that both the dye molecules and SWNT formed aggregates. At lower concentrations such as 1 x 10^-9 M for terphenyl and 1 x 10^-6 M for anthracene, it was found that free dye and individual SWNT were interacting. Raman spectroscopy of the composites formed on interaction show vibrational modes that are not present in either the SWNTs or dye powders. It was found that both the dye and SWNTs had Infra Red (IR) active vibrational modes at the positions at which these new or unique Raman modes occur in the composite spectra. It is therefore thought that the new Raman modes in the composite samples are related to the IR modes. The Raman Radial Breathing Modes (RBMs) give detail as to how diameter selective the dye samples are when compared to the pristine SWNT modes. Red shifting of the RBMs for both composite spectra was observed. It is believed that such a result is due to the de-bundling of the SWNT on interaction with the dye molecules.

Proceedings Article | 3 June 2005 Paper

Use of Raman spectroscopy in the investigation of debundling of single walled carbon nanotubes

E. Gregan, S. Keogh, T. Hedderman, G. Chambers, H. Byrne

Proceedings Volume 5826, (2005) https://doi.org/10.1117/12.605062

KEYWORDS: Raman spectroscopy, Single walled carbon nanotubes, Semiconductors, Carbon nanotubes, Graphene, Carbon, Molecules, Imaging systems, Confocal microscopy, Macromolecules

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Proceedings Article | 27 August 2003 Paper

Physical interactions between HiPco SWNTs and semiconjugated polymers

Sinead Keogh, A. Maguire, Theresa Hedderman, Elizabeth Gregan, Garrett Farrell, Alan Dalton, Brendan McCarthy, Gordon Chambers, Hugh Byrne

Proceedings Volume 4876, (2003) https://doi.org/10.1117/12.463665

KEYWORDS: Single walled carbon nanotubes, Polymers, Composites, Raman spectroscopy, Carbon nanotubes, Laser energy, Carbon, Absorption, Statistical analysis, Carbon monoxide

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Proceedings Article | 27 August 2003 Paper

Stokes/anti-Stokes Raman spectroscopy of HiPco single-walled carbon nanotubes

Elizabeth Gregan, Sinead Keogh, Theresa Hedderman, Gordon Chambers, Hugh Byrne

Proceedings Volume 4876, (2003) https://doi.org/10.1117/12.463955

KEYWORDS: Raman spectroscopy, Single walled carbon nanotubes, Carbon nanotubes, Semiconductors, Near infrared, Graphene, Absorption, Carbon, Spectroscopy, Absorption spectroscopy

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Proceedings Article | 27 August 2003 Paper

Single-wall carbon nanotubes as templates for organic molecules

Theresa Hedderman, Luke O'Neill, A. Maguire, Sinead Keogh, Elizabeth Gregan, Brendan McCarthy, Alan Dalton, Gordon Chambers, Hugh Byrne

Proceedings Volume 4876, (2003) https://doi.org/10.1117/12.463634

KEYWORDS: Single walled carbon nanotubes, Molecules, Luminescence, Composites, Carbon nanotubes, Molecular interactions, Raman spectroscopy, Magnesium, Molecular spectroscopy, Polymers

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Showing 5 of 6 publications

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