Search results for "Films"

Chromogenic and fluorogenic reagents for chemical warfare nerve agents' detection

2008

The ease of production, the extreme toxicity of organophosphorus-containing nerve agents, and their facile use in terrorism attacks underscores the need to develop accurate systems to detect these chemicals. Among different technologies we review here recent advances in the design of chromo-fluorogenic methods for the specific detection of nerve agents. Optical sensing (especially colorimetric detection) requires usually low-cost and widely used instrumentation and offers the possibility of so-called “naked eye detection”. Recent reported examples suggest that the application of chromo-fluorogenic supramolecular concepts for the chromogenic or fluorogenic sensing of nerve agents might be an…

Observable Electric Potential and Electrostatic Potential in Electrochemical Systems

1999

The role of the electric potential in the description of transport processes in electrochemical systems is critically analyzed. Since the electrostatic potential drop between two parts of a system ...

Low temperature plasma treatment of monomolecular Langmuir-Blodgett films

1993

Abstract The structure of the surface layer of materials is usually quite different from the bulk. Detailed information about the surface structure is often not available. This, together with the complex nature of low temperature plasma treatment, hinders the investigations of plasma chemical processes on solid surfaces. Monomolecular Langmuir-Blodgett (LB) structures offer a unique opportunity to prepare model surfaces with known thickness and molecular architecture. From the data obtained, the depth of the Ar plasma influence on solid organic surfaces was estimated to be about 400–1000 A depending on the nature of the surface layer. An oxygen plasma penetrates deeper with a penetration li…

Caries arresting effect of silver diamine fluoride on dentine carious lesion with S. mutans and L. acidophilus dual-species cariogenic biofilm

2013

OBJECTIVES: This in vitro study investigated the effects of silver diamine fluoride (SDF) on dentine carious lesion with cariogenic biofilm. STUDY DESIGN: Thirty human dentine blocks were inoculated with Streptococcus mutans and Lactobacillus acidophilus dual-species biofilm to create carious lesion. They were equally divided into test and control group to receive topical application of SDF and water. After incubation anaerobically using micro-well plate at 37oC for 7 days, the biofilms were evaluated for kinetics, morphology and viability by colony forming units (CFU), scanning electron microscopy (SEM), and confocal microscopy (CLSM), respectively. The carious lesion underwent crystal cha…

Fluorination of Cu(001) Surface by C60F48 Molecule Adsorption

2019

Copper surface functionalization by defluorination of C60F48 molecules with submonolayer and monolayer coverages on the Cu(001) crystal is studied by X-ray photoelectron spectroscopy. At room tempe...

Size-controlled magnetic nanoparticles in surfactant-rich thin films: a combined EXAFS, SAXS, AFM and MFM study

2008

Discrimination of nerve gases mimics and other organophosphorous derivatives in gas phase using a colorimetric probe array.

2012

A colorimetric array for the chromogenic discrimination of organophosphorous derivatives in gas phase has been developed. The array allows us to classify the nerve agent simulants DFP, DCP and DCNP.

Probing the Multiple Structures of Vaterite through Combined Computational and Experimental Raman Spectroscopy.

2014

First-principles Raman spectra have been computed for several new vaterite structural models that have been recently proposed, and compared with spectra recorded on a set of biogenic, geological and synthetic samples. This set includes new measurements collected on Herdamania momus spicules (Great Barrier Reef, Queensland, Australia), which are known to have purity and crystallinity that are higher than for other biogenic samples. Overall, due to the close structural connection between the various models, the computed Raman spectra are found to be broadly similar. However, the spectra obtained for the two most stable models (monoclinic C2 and trigonal P3221, corresponding to two different p…

The adhesion properties of the Ag/α-Al2O3() interface: an ab initio study

2002

Ab initio computer simulations of the atomic and electronic structure of the Ag/a-Al2O3(0 0 0 1) (corundum) interface have been performed for a periodic two-dimensional slab model using the Hartree–Fock method and a posteriori electron correlation corrections.We have considered both Al- and O-terminated corundum substrate surfaces.The dependence of the adhesion energy on the interfacial distance has been analyzed for the two most favorable Ag adsorption positions over corundum and for two different metal coverages (a 1/3 monolayer (ML) of the Ag(1 1 1) crystallographic plane and a full Ag(1 1 1) monolayer).The two different terminations (Al- and O-) give rise to qualitatively different resu…

Metal film growth on regular and defective MgO(001) surface: A comparative ab initio simulation and thermodynamic study

2006

Abstract In order to understand the difference in metallic film growth modes on perfect and defective oxide substrates, we have combined ab initio B3LYP periodic calculations on the slab models of the corresponding Me/MgO(0 0 1) interfaces (Me = Ag, Cu) with thermodynamic theory of solid solutions. For a defectless magnesia surface, we confirm the experimentally observed submonolayer growth of 3D metallic islands (Ag possesses a higher trend than Cu). Formation of Fs centers (neutral O vacancies) on the substrate markedly enhances metal atom adsorption as compared to physisorption over regular sites on a defect-free substrate. For the first time, we predict that the presence of these surfac…