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Study Findings from Valencia Polytechnic University Provide New Insights into Biological Pigments

February 11, 2014

By a News Reporter-Staff News Editor at Life Science Weekly -- A new study on Biological Factors is now available. According to news originating from Valencia, Spain, by NewsRx correspondents, research stated, "Double-wall carbon nanotubes (DWCNTs) with pyridyl units covalently attached to the external wall through isoxazolino linkers and carboxylic groups that have been esterified by pentyl chains are synthesized. The properties of these modified DWCNTs are then compared with an analogous sample based on single-wall carbon nanotubes (SWCNTs)."

Our news journalists obtained a quote from the research from Valencia Polytechnic University, "Raman spectroscopy shows the presence of characteristic radial breathing mode vibrations, confirming that the samples partly retain the integrity of the nanotubes in the case of DWCNTs, including the internal and external nanotubes. Quantification of the pyridyl content for both samples (DWCNT and SWCNT derivatives) is based on X-ray photoelectron spectroscopy and thermogravimetric profiles, showing very similar substituent load. Both pyridyl-containing nanotubes (DWCNTs and SWCNTs) form a complex with zinc porphyrin (ZnP), as evidenced by the presence of two isosbestic points in the absorption spectra of the porphyrin upon addition of the pyridyl-functionalized nanotubes. Supramolecular complexes based on pyridyl-substituted DWCNTs and SWCNTs quench the emission and the triplet excited state identically, through an energy-transfer mechanism based on pre-assembly of the ground state. Thus, the presence of the intact inner wall in DWCNTs does not influence the quenching behavior, with respect to SWCNTs, for energy-transfer quenching with excited ZnP."

According to the news editors, the research concluded: "These results sharply contrast with previous ones referring to electron-transfer quenching, in which the double-wall morphology of the nanotubes has been shown to considerably reduce the lifetime of charge separation, owing to faster electron mobility in DWCNTs compared to SWCNTs."

For more information on this research see: Double-Wall Carbon Nanotube-Porphyrin Supramolecular Hybrid: Synthesis and Photophysical Studies. Chemphyschem, 2014;15(1):100-108. Chemphyschem can be contacted at: Wiley-V C H Verlag Gmbh, Boschstrasse 12, D-69469 Weinheim, Germany. (Wiley-Blackwell -; Chemphyschem -

The news correspondents report that additional information may be obtained from M. Vizuete, Valencia Polytechnic University, Inst Univ Tecnol Quim CSIC UPV, Valencia 46022, Spain. Additional authors for this research include M.J. Gomez-Escalonilla, J.L.G. Fierro, P. Atienzar, H. Garcia and F. Langa (see also Biological Factors).

Keywords for this news article include: Spain, Europe, Valencia, Fullerenes, Porphyrins, Nanotechnology, Supramolecular, Carbon Nanotubes, Biological Factors, Biological Pigments, Emerging Technologies

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Source: Life Science Weekly

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