Opto-electronic properties of single-walled carbon nanotubes can be significantly modified by chromophore confinement into their hollow core. This presentation deals with quaterthiophene derivatives encapsulated into nanotubes displaying different diameter distributions. We show that the supramolecular organizations of the confined chromophores depend on the nanocontainer size. The Raman radial breathing mode frequency is monitored by both the number of confined molecules into a nanotube section and the competition between dye/dye and dye/tube wall interactions. The confinement properties lead also to an exaltation of the infrared absorption response1 in single-walled carbon nanotubes from dye molecule interactions due to a symmetry breaking, allowing us, thanks to the complementarity of DFT calculations and experimental IR investigations to study interactions between both subsystems. Significant electron transfer from the confined molecules to the nanotubes is also reported from Raman investigations. This charge transfer leads to an important enhancement of the photoluminescence intensity by a factor of nearly five depending on the tube diameter. In addition, close to the molecule resonance, the magnitude of the Raman G-band shifts is modified and the intensity loss is amplified, indicating a photo-induced electron transfer. Results are discussed in the frame of electron-phonon coupling. Thus, confinement species into nanotubes allow moving the Fermi level and consequently to monitor their opto-electronic properties.

Opto-electronic properties of single-walled carbon nanotubes can be significantly modified by chromophore confinement into their hollow core. This presentation deals with quaterthiophene derivatives encapsulated into nanotubes displaying different diameter distributions. We show that the supramolecular organizations of the confined chromophores depend on the nanocontainer size. The Raman radial breathing mode frequency is monitored by both the number of confined molecules into a nanotube section and the competition between dye/dye and dye/tube wall interactions. The confinement properties lead also to an exaltation of the infrared absorption response in single-walled carbon nanotubes from dye molecule interactions due to a symmetry breaking, allowing us, thanks to the complementarity of DFT calculations and experimental IR spectra to study interactions between both subsystems. Significant electron transfer from the confined molecules to the nanotubes is also reported from Raman investigations. This charge transfer leads to an important enhancement of the photoluminescence intensity by a factor of nearly five depending on the tube diameter. In addition, close to the molecule resonance, the magnitude of the Raman G-band shifts is modified and the intensity loss is amplified, indicating a photo-induced electron transfer. Results are discussed in the frame of electron-phonon coupling. Thus, confinement species into nanotubes allow moving the Fermi level and consequently to monitor their opto-electronic properties.

Different intracellular delivery systems of bioactive compounds have been developed, including cell-penetrating peptides. Although usually nontoxic and biocompatible, these vectors share some of the general drawbacks of peptides, notably low bioavailability and susceptibility to protease degradation, that limit their use. Herein, the conversion of short peptide sequences into poly-a-amino-g-lactam foldamers that adopt a ribbon-like structure is investigated. This template is used to distribute critical cationic and/or hydrophobic groups on both sides of the backbone, leading to potent short, cell-permeable foldamers with a low positive-charge content. The lead compound showed dramatically improved protease resistance and was able to efficiently deliver a biologically relevant cargo inside cells. This study provided a simple strategy to convert short peptide sequences into efficient protease-resistant cell-penetrating foldamers.

The use of electrochemical template synthesis for the formation of electrochromic composite nickel hydroxide/PVA films with poor inside stress, effective adhesion to substrate and high optical and electrochemical properties is proposed.Influence of the deposition current density and of the amount of PVA on the structure, surface morphology and transparency of the electrodeposit films is investigated. It is thus concluded that the optimal current density is 0.625 mA/cm2 for the pure Ni(OH)2 film whereas the optimal concentration of PVA is 5% weight is. Overall, the electroplated Ni(OH)2/PVA films exhibit an X-ray amorphous structure, due to the Ni(OH)2 particle growth in the nano-size cells of the 3D network of the PVA template. Surface morphology of films, deposited with the template synthesis, is investigated by SEM. The film electrodepositing rate by template synthesis was estimated around the 3.87 μm/h at the current density of the 0.625 mA/cm2. Template incorporating into the nickel hydroxide film has been proved by EDX analysis. Electrochemical and electrochromic properties of films, deposited by electrochemical template synthesis and dried at 20 °C and 90 °C, have been investigated. It was shown that both types of films have high properties (charge/discharge and colorization-bleaching processes). But films, dried at 20 °C, has the best electrochemical properties and larger colorization depth, however the colorization/bleaching process has larger reversibility for the sample dried at 90 °C

The rise of efficient extraction techniques triggered a renewal of interest in semiconducting carbon nanotubes (s-SWNT) research. It represents a great interest for optoelectronics, with outstanding properties in field-effect transistor, and s-SWNT ability to efficiently emit light in the near-IR range. In particular, polyfluorene (PFO) wrapped s‑SWNT (s-SWNT@PFO) display strong photoluminescence, and could be coupled with photonic devices such as microring resonators [1,2] to control photoluminescence linewidth and enhance photoluminescence intensity.The main challenge for using s-SWNT@PFO in optoelectronics lies in the difficulty to establish good electrical contact with a PFO embedded carbon nanotube. We propose to investigate these issues by tuning the amount of PFO wrapping around s-SWNT. A low pressure annealing process is used to selectively remove PFO around s‑SWNT without burning nanotubes themselves (Figure). The resulting s-SWNT@PFO networks are then probed by AFM, Raman spectroscopy, absorption, photoluminescence and electrical experiments.

Nanophotonics is an emerging field where researchers look for potential application of carbon nanotubes (SWNT) in the framework of silicon photonics technology, due to SWNT ability to emit, modulate and detect light in the wavelength range of silicon transparency.In this field of nanotube photonics, a first milestone was to couple light emission from SWNT into silicon waveguides [1]. Current researches focus on coupling SWNT with optical cavities, either for enhancing nanotube photoluminescence (PL) or nonlinear optical phenomena at the nanoscale, using microdisk resonators, or photonic crystal cavities. However, these kinds of cavities could not be easily coupled to silicon waveguides, hindering subsequent integration into more complex photonic devices.Building up on our previous work [2], we propose to couple SWNT PL with silicon microring resonators in a fully integrated configuration, with an acess waveguide [3]. PL coupled to microring modes could be collected from the access waveguide, with efficient rejection on non-resonant photons. Emission quality factor up to 8000 were observed. This design allow for collinear excitation of SWNT through the access waveguide, leading to efficient excitation and collection of SWNT PL at different wavelengths. The requirement for out-of-the-plane SWNT excitation is lifted, underlining the pertinence of this approach for realistic carbon nanotube based photonic devices.References1. E. Gaufrès, N. Izard, A. Noury, X. Le Roux, G. Rasigade, A. Beck and L. Vivien, ACS Nano 6, 3813 (2012)2. A. Noury, X. Le Roux, L Vivien and N. Izard, Nanotechnology 25, 215201 (2014)3. A. Noury, X. Le Roux, L. Vivien and N. Izard, Nanotechnology 26, 345201 (2015)