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Confinement dans les nanotubes
(3) Production(s) de l'année 2024
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Impact of Single-Walled Carbon Nanotube Functionalization on Ion and Water Molecule Transport at the Nanoscale 
Auteur(s): Mejri Alia, Arroyo Nicolas, Herlem Guillaume, Palmeri J., Manghi Manoel, Henn F., Picaud Fabien
(Article) Publié:
Nanomaterials, vol. 14 p.117 (2024)
Ref HAL: hal-04411217_v1
DOI: 10.3390/nano14010117
Exporter : BibTex | endNote
Résumé: Nanofluidics has a very promising future owing to its numerous applications in many domains. It remains, however, very difficult to understand the basic physico-chemical principles that control the behavior of solvents confined in nanometric channels. Here, water and ion transport in carbon nanotubes is investigated using classical force field molecular dynamics simulations. By combining one single walled carbon nanotube (uniformly charged or not) with two perforated graphene sheets, we mimic single nanopore devices similar to experimental ones. The graphitic edges delimit two reservoirs of water and ions in the simulation cell from which a voltage is imposed through the application of an external electric field. By analyzing the evolution of the electrolyte conductivity, the role of the carbon nanotube geometric parameters (radius and chirality) and of the functionalization of the carbon nanotube entrances with OH or COO− groups is investigated for different concentrations of group functions.
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Revealing two chemical strategies to tune bright one- and two-photon excited fluorescence of carbon nanodots
Auteur(s): Mucha S., Firlej L., Formalik F., Bantignies J.-L., Anglaret E., Samoć Marek, Matczyszyn Katarzyna
(Article) Publié:
Journal Of Materials Chemistry C, vol. p. (2024)
Ref HAL: hal-04398741_v1
DOI: 10.1039/D3TC03211F
Exporter : BibTex | endNote
Résumé: Carbon-based dots (CDs) are a novel class of luminescent carbon nanomaterials that have attracted much attention as promising alternatives for cadmium-based quantum dots and fluorescent organic dyes. Although different strategies have been proposed to produce CDs with intense and tuneable one-photon excited fluorescence (OPEF), the case of analogous two-photon excited fluorescence (TPEF) has not been fully explored yet. By varying the synthesis conditions, we produced three types of phloroglucinol-based carbon nanodots (PG CNDs). Their remarkable OPEF and TPEF properties can be tuned by (Ia) the conjugated aromatic domains and (Ib) the content of oxygenous moieties. In addition, the emission colour of the PG CNDs is strongly responsive to (II) the hydrogen-bonding network, enabling colour-switching while maintaining excellent fluorescence yields (both OPEF and TPEF). These three factors were evaluated for their suitability for the tuning of the emission colour. Our studies point out the advantages of the tuneable PG CNDs to be used in optoelectronics and biological application domains.
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Influence of the Quantum Capacitance on Electrolyte Conductivity through Carbon Nanotubes
Auteur(s): Hennequin-Nespoulous Théo, Manghi Manoel, Noury A., Henn F., Jourdain V., Palmeri J.
(Article) Publié:
Journal Of Physical Chemistry Letters, vol. 15 p.2177–2183 (2024)
Texte intégral en Openaccess : 
Ref HAL: hal-04234607_v1
Ref Arxiv: 2307.12071
DOI: 10.1021/acs.jpclett.3c03248
Ref. & Cit.: NASA ADS
Exporter : BibTex | endNote
Résumé: In recent experiments, unprecedentedly large values for the conductivity of electrolytes through carbon nanotubes (CNTs) have been measured, possibly owing to flow slip and a high pore surface charge density whose origin is still unknown. By accounting for the coupling between the {quantum} CNT and the {classical} electrolyte-filled pore capacitances, we study the case where a gate voltage is applied to the CNT. The computed surface charge and conductivity dependence on reservoir salt concentration and gate voltage are intimately connected to the CNT electronic density of states. This approach provides key insight into why metallic CNTs have larger conductivities than semi-conducting ones.
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