Electrodeposition is a versatile method for synthesizing nanostructured films, but controlling the morphology of films containing two or more elements requires a detailed understanding of the deposition process. We used liquid cell transmission electron microscopy to follow the electrodeposition of PtNi nanoparticle films on a carbon electrode during cyclic voltammetry. These observations show that the film thickness increases with each cycle, and by the fourth cycle, branched and porous structures could be deposited.
View Article and Find Full Text PDFA current challenge in silicon chemistry is to perform liquid-phase synthesis of silicon nanoparticles, which would permit the use of colloidal synthesis techniques to control size and shape. Herein we show how silicon nanoparticles were synthesized at ambient temperature and pressure in organic solvents through a redox reaction. Specifically, a hexacoordinated silicon complex, bis(,'-diisopropylbutylamidinato)dichlorosilane, was reduced by a silicon Zintl phase, sodium silicide (NaSi).
View Article and Find Full Text PDFNoble metal nanostructured films are of great interest for various applications including electronics, photonics, catalysis, and photocatalysis. Yet, structuring and patterning noble metals, especially those of the platinum group, is challenging by conventional nanofabrication. Herein, an approach based on solution processing to obtain metal-based films (rhodium, ruthenium (Ru) or iridium in the presence of residual organic species) with nanostructuration at the 20 nm-scale is introduced.
View Article and Find Full Text PDFDue to their high porosity and chemical versatility, metal-organic frameworks (MOFs) exhibit physical properties appealing for photonic-based applications. While several MOF photonic structures have been reported, examples of applications thereof are mainly limited to chemical sensing. Herein, the range of application of photonic MOFs is extended to local thermal and photothermal sensing by integrating them into a new architecture: MOF photonic balls.
View Article and Find Full Text PDFA goal in the field of nanoscale optics is the fabrication of nanostructures with strong directional light scattering at visible frequencies. Here, the synthesis of Mie-resonant core-shell particles with overlapping electric and magnetic dipole resonances in the visible spectrum is demonstrated. The core consists of silicon surrounded by a lower index silicon oxynitride (SiON) shell of an adjustable thickness.
View Article and Find Full Text PDFSilicon has emerged as the most desirable material for optical dielectric metamaterials, however chemists struggle to obtain the required silicon nanoparticle dimensions. Here the average diameter of silicon nanoparticles is varied between 3 and 15 nm by changing the reaction solvent. Electrochemistry and NMR elucidate the role of solvent on the synthetic mechanism.
View Article and Find Full Text PDFMetamaterials have optical properties that are unprecedented in nature. They have opened new horizons in light manipulation, with the ability to bend, focus, completely reflect, transmit, or absorb an incident wave front. Optically active metamaterials in particular could be used for applications ranging from 3D information storage to photovoltaic cells.
View Article and Find Full Text PDFThe authors propose a reversible bilio-pancreatic diversion with access to the bypassed stomach. In the Messina technique, bilio-pancreatic diversion is accomplished by transecting the stomach without gastric resection, as already described by Resa et al. In addition, a temporary gastrostomy is performed on the excluded stomach and allows direct postoperative exploration of the duodenum and the biliary tree.
View Article and Find Full Text PDFLaparoscopic adjustable gastric banding (LAGB) is one of the most common bariatric procedures performed in Europe and Australia. Major post-operative complications are limited but once they occur, prompt diagnosis and treatment are mandatory. LAGB complications are related either to the port and the connecting tube, such as infection or tubing disconnection and migration, or to the band, such as slippage, pouch dilatation, or intra-gastric migration.
View Article and Find Full Text PDFTo compare the early and intermediate results of the open and laparoscopic tension-free repair of incisional hernia, 24 patients were randomized prospectively to undergo laparoscopic or open repair of incisional hernia with retromuscular placement of the prosthesis using transabdominal sutures for mesh fixation. All the procedures were completed as planned. The mean duration of surgery was not significantly different between the 2 groups (P=0.
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