Bacsa W.S. – TechConnect Briefs

Interlayer interaction and disorder in Few Layer Graphene (FLG) powders prepared by fluidized bed chemical vapor deposition

Bacsa R., Bacsa W.S., Serp Ph., Lecante P., Pavlenko E., Cameán I., Ramos A., Garcia A.B., Bacsa R., Bacsa W.S., University of Toulouse, FR

The growth of few layer graphene (FLG) in powder form by CVD is particularly promising for its large scale production and use in composites as well as electrochemical and energy applications. The electronic and mechanical [...]

Correlating electrical and structural properties in surface layer of carbon nanotube polymer composite

Pavlenko E., Tishkova V., Puech P., Bacsa W.S., CNRS and University of Toulouse, FR

We have recently shown that annealing of agglomerated carbon nanotubes on thermoplast polymers form surface composite films (70 micrometers) (1). This has been explained by preferential carbon nanotubes absorption of infrared radiation leading to local [...]

Unusual thermal diffusion of carbon nanotubes in a thermoplastic polymer

Tishkova V., Pavlenko E., Puechmont P., Flahaut E., Bacsa W.S., CEMES, Univ. Toulouse, FR

The dispersion of carbon nanotubes in polymer composites is a major challenge. Although nanotubes have a high aspect ratio, their tendency to agglomerate limit percolation at low loading. We find that thermal diffusion is reducing [...]

Dispersing carbon nanotubes in polymer nanocomposites: detecting individually dispersed tubes

Tishkova V., Bonnet G., Puechmont P., Flahaut E., Bacsa W.S., CEMES, Univ. Toulouse, FR

Carbon nanotubes (CNTs) are used to make polymer composites conductive. Small amounts of CNTs (0.1-1 wt%) increase the conductivity by several orders of magnitude. The electrical percolation threshold depends strongly on the dispersion state of [...]

Effect of doping on the radial breathing mode of carbon nanotubes

Gerber I.C., Puech P., Gannouni A., Bacsa W.S., CEMES-CNRS, FR

Doping CNTs is an attractive alternative to control the electronic conductivity of CNTs independent of their diameter. Highly conducting nanotubes are of interest for applications in transparent thin film electrodes. When doping CNTs through substitution [...]

Vibrational spectroscopy of nanoscale needle shaped histamine

Sonois V., Faller P., Bacsa W.S., Fazouan N., Estève A., University Paul Sabatier, FR

Amino acids in aqueous solutions have low Raman signals and are difficult to detect at low concentrations. To increase Raman signals one often uses UV excitation. We find that nano-needels can be grown from droplets [...]

Depth resolution capabilities using optical standing waves near surfaces

Neumayer F., Bacsa W.S., University Paul Sabatier, FR

The physics of standing waves has been explored for more than 50 years. Standing wave fields can be used to selectively enhance luminescence or enhance the Raman signal. We explore here the optical standing wave [...]

Heating double wall carbon nanotubes with UV photons

Puech P., Bassil A., Flahaut E., Bacsa W.S., University Paul Sabatier, FR

Light absorption leads inevitably to electronic excitation and inelastic electron scattering, creating phonons and resulting in the increase of the lattice temperature. By using photons with energies significantly above the fundamental band gap of the [...]

Local diffuse light scattering and surface inspection

Caumont M., Bacsa W.S., University Paul Sabatier, FR

Overlap of the incident and scattered field from local surface non-uniformities lead to lateral standing waves which can be mapped using a scanning optical probe in collection mode. The lateral standing waves form diffraction fringes [...]

Cubic and oriented Ag nano-particles by high vacuum evaporation

Berner D., Zuppiroli L., Caumont M., Bacsa W.S., University Paul Sabatier, FR

Optical properties of metal nanoparticles depend strongly on size and shape. Controlling these parameters implies improving the control of their optical properties. Metal nanoparticles find applications in photonics, biological labeling and catalysis. A number of [...]