Raman spectroscopy of BN-SWNTs

We present results on the vibrational properties of BN-SWNTs together with a study of the synthesis material by transmission electron microscopy. Phonon modes have been investigated by Raman spectroscopy with laser excitation wavelengths in the range from 363.8 to 676.44 nm. The assignment of the modes is guided by ab-initio calculations

Revisiting urea-based gelators: strong solvent- and casting-microstructure dependencies and organogel processing using an alumina template

Urea-based gelators have been thoroughly characterized through various techniques and exhibit a strong solvent-structuration dependency in both the gel and the xerogel states. In a ground-breaking manner, gels were introduced in alumina membranes, which act as templates, in order to shape these materials and force the alignment of the corresponding self-assembled nanofibers by confinement

Spectroscopic Evidence of Carbon Nanotubes’ Metallic Character Loss Induced by Covalent Functionalization via Nitric Acid Purification

A detailed characterization of covalently functionalized HiPco single-walled carbon nanotubes (SWNTs) has been carried out using several physicochemical methods (thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and Raman scattering). The chemical process, finally leading to SWNT?ester derivatives, starts from nitric acid purification of pristine SWNTs. Besides the efficiency of the functionalization, we show that a loss of metallic character of the carbon nanotubes is initiated by the nitric acid treatment of pristine SWNTs and is maintained in the final SWNT ester derivatives. A higher reactivity of the metallic tubes is also demonstrated

Tuning the Raman Resonance Behavior of Single-Walled Carbon Nanotubes via Covalent Functionalization

We present a systematic Raman study over a range of excitation energies of arc discharge single-walled carbon nanotubes (SWCNTs) covalently functionalized according to two processes, esterification and reductive alkylation. The SWCNTs are characterized by resonance Raman spectroscopy at each step of the functionalization process, showing changes in radial breathing mode frequencies and transition energies for both semiconducting and metallic tubes. Particular attention is given to a family of tubes clearly identified in the Kataura plot for which we continuously tune the excitation energy from 704 to 752 nm. This allows us to quantify the energy shift occurring in the spacing of the van Hove singularities. We demonstrate that, independently of the functionalization technique, the type of chain covalently bound to the tubes plays an important role, notably when oxygen atoms lie close to the tubes, inducing a larger shift in transition energy as compared to that of other carbonaceous chains. The study shows the complexity of interpreting Raman data and suggests many interpretations in the literature may need to be revisited

Opportunities for polymer-based nanowires in optoelectronics and nanophotonics

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Opportunities for polymer-based nanowires in optoelectronics and nanophotonics

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Raman and FTIR studies on electro-reduction of single-walled carbon nanotube films in the presence of Li salts

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Raman and SERS studies of single-walled carbon nanotubes and Nanotubes/Conjugated polymers composites

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Vibrational and photoluminescence properties of composites based on zinc oxide and single-walled carbon nanotubes

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