Search results for "BIM"

Ultrastable, Uniform, Reproducible, and Highly Sensitive Bimetallic Nanoparticles as Reliable Large Scale SERS Substrates

2015

International audience; A strong interest exists in developing surface-enhanced Raman spectroscopy (SERS) substrates that uniformly enhance Raman signals of chemical and biological molecules over large scales while reaching the detection limit of trace concentrations. Even though the resonant excitation of localized surface plasmons of single or assembled metallic nanoparticles used in SERS substrates can induce large electromagnetic fields, these substrates display a SERS activity which suffers from poor reproducibility, uniformity, and stability, preventing them from being reliable for applications. In this work, we have developed self-supported large scale Ag/Au bimetallic SERS-active su…

Insertion of Magnetic Bimetallic Oxalate Complexes into Layered Double Hydroxides

2006

Bimetallic oxalate complexes have been successfully inserted into layered double hydroxides as ferromagnetic oxalate-bridged oligomers. Different preparation methods afford different sizes and compositions for the oligomers. In all cases, no magnetic ordering has been observed above 2 K.

Modeling bimetallic corrosion under thin electrolyte films

2011

A finite element model (FEM) was developed to calculate the potential distribution in the electrolyte in the case of bimetallic corrosion between iron and zinc electrodes, taking into account mass transport of oxygen in the solution. This model was first compared with experimental results obtained by scanning vibrating electrode technique (SVET) on a galvanized steel cut-edge in immersion conditions in a 0.03 M NaCl electrolyte. A good agreement was obtained between the calculated and experimental current densities. The model predicted the evolution of the galvanic coupling as function of the electrolyte thickness and for various iron–zinc surface area ratios. Different coupling regimes wer…

Compressibility and structural stability of ultra-incompressible bimetallic interstitial carbides and nitrides

2012

We have investigated by means of high-pressure x-ray diffraction the structural stability of Pd 2Mo 3N, Ni 2Mo 3C 0.52N 0.48, Co 3Mo 3C 0.62N 0.38, and Fe 3Mo 3C. We have found that they remain stable in their ambient-pressure cubic phase at least up to 48 GPa. All of them have a bulk modulus larger than 330 GPa, the least compressible material being Fe 3Mo 3C, B 0 = 374(3) GPa. In addition, apparently a reduction of compressibility is detected as the carbon content is increased. The equation of state for each material is determined. A comparison with other refractory materials indicates that interstitial nitrides and carbides behave as ultra-incompressible materials. © 2012 American Physic…

XPS study of pumice-supported palladium and platinum catalysts

1992

An XPS study has been performed on samples of monometallic of palladium and platinum and on bimetallic Pd-Pt catalysts supported on pumice. A negative shift of about 0.5 eV in the Pd 3d and Pt 4f binding energies of the catalysis relative to the energies of the same levels in the pure metals suggested an increase in the electron density in both metals. A quantitative XPS analysis indicated that the supported metals did not modify the surface atomic composition of pumice

Mechanical Properties of Deformed Interfaces in Bimetallic Joints

2003

MOF-Mediated Synthesis of Supported Fe-Doped Pd Nanoparticles under Mild Conditions for Magnetically Recoverable Catalysis**

2020

Metal–organic framework (MOF)-driven synthesis is considered as a promising alternative for the development of new catalytic materials with well-designed active sites. This synthetic approach is used here to gradually transform a new bimetallic MOF, with Pd and Fe as the metal components, by the in situ generation of aniline under mild conditions. This methodology results in a compositionally homogeneous nanocomposite formed by Fe-doped Pd nanoparticles that, in turn, are supported on iron oxide-doped carbon. The nanocomposite has been fully characterized by several techniques such as IR and Raman spectroscopy, TEM, XPS, and XAS. The performance of this nanocomposite as an heterogeneous cat…

Wavelength-Selective Softening of Hydrogel Networks.

2021

Photoresponsive hydrogels hold key potential in advanced biomedical applications including tissue engineering, regenerative medicine, and drug delivery, as well as intricately engineered functions such as biosensing, soft robotics, and bioelectronics. Herein, the wavelength-dependent degradation of bio-orthogonal poly(ethylene glycol) hydrogels is reported, using three selective activation levels. Specifically, three chromophores are exploited, that is, ortho-nitrobenzene, dimethyl aminobenzene, and bimane, each absorbing light at different wavelengths. By examining their photochemical action plots, the wavelength-dependent reactivity of the photocleavable moieties is determined. The wavele…

Low Temperature Investigation of the Thermal and Magnetic Properties of 1-d Ferrimagnetic Systems

1987

The series of structurally ordered bimetallic chains formulated as MM′ (EDTA).6H2O, in short (MM′), provides the most versatile known example of 1-dimensional ferrimagnets, since on the same structural support many different magnetic ions (Mn, Co, Ni and Cu(II)) can be selectively accommodated.1 Consequently, many choices of alternating magnetic moments with Heisenberg or Ising exchange couplings can be investigated. Moreover, taking into account that the M-M′ distances along the chain are alternating, this series could show at the same time an alternation of the exchange parameter2.

Submicrometer CaCuO2 and Ca2CuO3 particles from bimetallic formate precursors

1992

Abstract CaCuO2 and Ca2CuO3 are readily obtained by thermal decomposition of two new calcium and copper formates, CaCu(HCOO)4 and Ca2Cu(HCOO)6. These chemical-precursor based syntheses, while overcoming problems related to the stoichiometry of the final products, involve very short diffusion path lengths. This, in turn, results in soft treatments yielding pure phases constituted by submicrometer (≈0.4 μm) homogeneous particles.