Curing kinetics of an industrially important printedcircuitboard (PCB) base material (epoxy–phenol/glass fillers)were studied by isothermal differential scanning calorimetry(DSC) measurements between 150 and 190°C, as relevant curingtemperatures for the PCB industry. The extent of cure was calculatedby integration of the exothermic peak and normalizationby the total heat of reaction (obtained by nonisothermal DSC).Although the cross-linking was completed above 180°C, thekinetic profiles show two regimes: one fast and one slow. Thekinetic parameters have been elucidated using an isoconversionalmodel-free kinetic method, with the exact method of Friedman,to give to the PCB manufacturers a road map to predict curingbehavior of base material. The linearity of Arrhenius plots wassatisfactory. The apparent activation energy of curing reactionhas been found to increase with the degree of conversion. Theelucidation of the kinetic parameters allows us to propose anaccurate and predictive description of the curing kinetics withinthe fast regimen of reaction (i.e., without vitrification). Finally,we discuss how these kinetic measurements and models can becompleted and optimized.

We simulated the low temperature (T = 77 K) hydrogen adsorption in carbon slit-shaped nanopores using consecutively united atom (UA) and all atom (AA) representation of hydrogen molecule. We showed that both approximations give comparable estimation of the amount stored, for the wide range of pore width (0.6-2.5 nm). We also showed that at very high pressure (P = 400 bar, corresponding to the fugacity f used in grand canonical Monte Carlo simulations of f = 800 bar) the density of the adsorbed hydrogen structures is larger than the density of bulk liquid at critical temperature (∼76 kg/m3). This result agrees with the experimental observation of the density of the order of 100 kg/m3 for the hydrogen adsorbed in microporous carbons, reported recently in the literature.

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)