A5026566905- Gold and Silver Nanoparticles Synthesis and Applications
- Electrowetting and Microfluidic Technologies
- Modular Robots and Swarm Intelligence
- Analytical Chemistry and Sensors
- Quantum Dots Synthesis And Properties
- TiO2 Photocatalysis and Solar Cells
- Laser-Ablation Synthesis of Nanoparticles
- Advanced Photocatalysis Techniques
- Nanocluster Synthesis and Applications
- Surface Modification and Superhydrophobicity
- Nonlinear Optical Materials Studies
- Biosensors and Analytical Detection
- Electrochemical Analysis and Applications
- Electrohydrodynamics and Fluid Dynamics
- Electrocatalysts for Energy Conversion
- Image Processing Techniques and Applications
- nanoparticles nucleation surface interactions
- Electrospun Nanofibers in Biomedical Applications
- Neuroscience and Neural Engineering
- Plasmonic and Surface Plasmon Research
- Gas Sensing Nanomaterials and Sensors
- Safety Systems Engineering in Autonomy
- Electrophoretic Deposition in Materials Science
- Digital Holography and Microscopy
- Spectroscopy and Laser Applications
Laboratoire des Multimatériaux et Interfaces
2015-2024
Université Claude Bernard Lyon 1
2015-2023
Centre National de la Recherche Scientifique
2000-2023
Corning (France)
2018
Forum Réfugiés - Cosi
2017
Parrot (France)
2017
Université de Lyon
2015
École Normale Supérieure
2014
Sorbonne Université
2000-2003
Columbia University
2003
Molecular surface enhanced Raman scattering (SERS) in compact clusters of 30−70 nm Ag nanocrystals has shown single molecule cross sections that are orders magnitude larger than free space luminescence sections. We analyze certain aspects this phenomenon with new numerical electromagnetic calculations, and we also present spectral depolarization data for rhodamine 6G scattering. stress the central role femtosecond radiative lifetime, spatial distribution excited electrons, near field far...
The photoreduction of silver ions by citrate, catalyzed on seeds, is used to synthesize disk-shaped nanoparticles in solution. reaction characterized transmission electron microscopy (TEM), atomic force (AFM), optical absorption spectroscopy, and measuring the ion concentration during reaction. irradiation wavelength determines final shape these particles due dependence Ag plasmon spectrum. quantum yield this has been calculated, a growth mechanism outlined.
Flat silver nanocrystals have been synthesized by using a soft chemical procedure that involves mixing two reverse micellar solutions. The resulting "nanodisks" display highly anisotropic optical properties attributed to their shape anisotropy. A dark-field TEM image of such nanodisk, illustrating its single crystal nature, is shown in the Figure.
This paper describes the first method for making nanodisks having similar aspect ratios and differing by their size. Flat, single-crystal silver in equilibrium with spheres are produced using colloidal solutions. The nanodisk size is tuned relative amount of reducing agent involved synthesis whereas remain same order magnitude. 3D shape determined transmission electronic microscopy weak-beam dark-field technique. These characterized such anisotropic shapes exhibit several plasmon resonance...
Electron-lattice energy exchanges are investigated in gold and silver nanoparticles with sizes ranging from 30 to 2.2 nm embedded different environments. Femtosecond pump-probe experiments performed the low-perturbation regime demonstrate a strong increase of intrinsic electron-phonon interaction for smaller than 10 due confinement effect.
By controlling solvent evaporation rates, it has been possible to form micrometer rings and hexagonal arrays made of nanocrystals different sizes, shapes materials. Such patterns are driven by surface tension gradients that induce Bénard−Marangoni instabilities in the liquid films. The resulting self-assembled structures consistent with theoretical prediction hydrodynamic instabilities.
Rings and hexagonal arrays of nanocrystals (see Figure), where the structures correspond to micrometer wavelength range, are shown be produced by controlling deposition conditions. Silver deposited from hexane in air form ring same other solvents or a quasi-saturated atmosphere react differently.
A process to synthesize continuous conducting nanofibers were developed using PEDOT:PSS as a polymer and an electrospinning method. Experimental parameters carefully explored achieve reproducible conductive synthesis in large quantities. In particular, relative humidity during the was proven be of critical importance, well doping post-treatment involving glycols alcohols. The synthesized fibers assembled mat on glass substrates, forming transparent electrode their optoelectronic have been...
α , β, and γ relaxation mechanisms have been identified in semicrystalline (45% of crystallinity) parylene-C (–H2C–C6H3Cl–CH2–)n films. C–Cl bonds induce the β-relaxation explain increase dielectric constant as frequency decreases usual temperatures operation for devices incorporating parylene-C. At cryogenic temperature (<−20 °C), γ-relaxation is assigned to local motions phenyl groups. Both β processes obey an Arrhenius law with activation energy Ea(β)=91.7 kJ/mole Ea(γ)=8.68...
This study focuses on electrowetting using two immmiscible liquids a dielectric coating. It is demonstrated that low contact angle of oil the hydrophobic surfaces key parameter to obtain hysteresis system, below 2 degrees . On basis these results, three aspects wetting properties have been studied: influence surface properties, design according surface, and graphical method solve Bartell-Osterhof equation predict surface. These results define clear rules useful for many applications from...
The influence of the substrate on morphology 2D and 3D superlattices made 5.8 nm silver sulfide nanocrystals coated with dodecanethiol is reported. two substrates used are highly oriented pyrolytic graphite (HOPG) molybdenum disulfide (MoS2). self-assemblies were characterized scanning electron microscopy atomic force techniques, it was found that self-organization in markedly differs used. These changes behavior explained terms particle−particle particle−substrate van der Waals interactions...
Experimental and calculated reflectivity spectra of silver nanocrystals self-assembled in compact hexagonal networks on various substrates [highly oriented pyrolytic graphite (HOPG), gold, silicon, ${\mathrm{Al}}_{0.7}{\mathrm{Ga}}_{0.3}\mathrm{As}]$ are compared. The deduced from a model based mean-field theory taking into account the electromagnetic resonances for p (parallel) s (perpendicular) polarizations. From experimental spectra, it is concluded that major change responses due to...
We have developed a miniature liquid lens component based on electro-wetting. It is designed to be plugged fix focus camera module provide both optical image stabilization (OIS) and auto-focus (AF) functions without any mobile mechanical parts. The OIS/AF features conical shape supporting the interface in order maintain stable axis multi-electrode design able induce an average tilt of when bias voltage applied different electrodes. size well adapted imaging applications with ¼ inch, 1/3 inch...
The optical and nonradiative relaxation dynamics of 5 nm thick silver nanodisks with a 25 diameter have been investigated in an organic solvent by continuous wave (cw) femtosecond pump−probe time-resolved spectroscopies. Several surface plasmon absorption bands are observed due to the disk shape these particles. In experiments, time dependence bleach resulting from pulsed excitation is studied. On 1−3 ps scale, decay electron−phonon observed. longer scale (>20 ps), rise rather than further...
We report photoelectrochemical measurements from mesoporous titanium dioxide filled with silver nanoparticles under illumination. A 200 mV potential switch of ion reduction is observed, depending on light wavelength. An easier in the presence linked to plasmon induced charge separation (PICS). SEM and TEM analysis before after photoelectrochemistry have also shown an electrochemical Ostwald ripening during continuous visible irradiation, a growth particles at sample surface. The combined use...
The self-assembly block copolymer method was used to synthesize mesoporous titania films and silver nanoparticles (NPs) were grown inside the films. Such NPs-titania are known for their multicolor photochromic properties due a photo-oxidation reaction of in presence under light excitation which is attributed plasmon induced charge separation. Here, photoelectrochemical these composite have been investigated at different wavelengths chemical environment order characterize light-induced redox...
Commercial electrowetting-based liquid lenses are optical devices containing two immiscible liquids as an medium. The first phase is a droplet of high refractive index oil placed in ring-shaped chassis. second electrically conductive and has similar density over wide temperature range. Droplet curvature difference determine the strength lens. Liquid take advantage electrowetting effect, which induces change interface's by applying voltage, thereby providing variable focal that useful...
A new generation of liquid lenses based on electrowetting has been developed, using a multi-electrode design, enabling to induce optical tilt and focus corrections in the same component. The basic principle is rely conical shape for supporting interface, insuring restoring force interface come at center position. design enables an average when bias voltage applied different electrodes. This reversible, vanishing cancelled. Possible application this lens component realization miniature camera...
A new method to measure surface energy based on competitive spreading of immiscible liquids is reported. This more sensitive polarity than standard methods and provides information chemistry pH sensitivity.
We explored polarization mechanisms at the interface between a dielectric material (an electrolyte) and an insulating liquid, during electrowetting actuation.