Two different silver colloids were prepared by chemical reduction of nitrate with trisodium citrate and hydroxylamine hydrochloride to compare their characteristics in relation possible use surface-enhanced Raman scattering (SERS) spectroscopy. The morphology plasmon resonance the single nanoparticles aggregates integrating these characterized means UV−vis absortion spectroscopy scanning electron microscopy, revealing important differences between each type nanoparticle as concerns physical...

To achieve low percolation thresholds in single wall carbon nanotube (SWCNT) and thermoplastic poly(butylene terephthalate) (PBT) composites, we have used an situ polycondensation reaction process. The intense dispersion process achieved first by ultrasonication followed ultrahigh speed stirring of nanotubes 1,4-butanediol the subsequent has made possible preparation nanocomposites which threshold is around 0.2 wt % SWCNT. This relatively value approaches those reported for based on...

Trace detection of polycyclic aromatic hydrocarbons is reported in this work on dithiocarbamate calix[4]arene functionalized Ag nanoparticles by using surface-enhanced Raman scattering (SERS). SERS spectra informed about the existence pollutant measuring its characteristic fingerprint vibrational features. In addition, revealed important structural information from both host and analyte which was crucial to understand deduce host-guest interaction mechanism. The effectiveness system checked...

The chemical modifications undergone by flavonoids under alkaline conditions in aqueous solution and on Ag nanoparticles studied optical spectroscopy are presented discussed.

The functionalization of silver nanoparticles (Ag NPs) by viologen dications (VGDs) is reported in this work as well their applications the surface-enhanced Raman scattering (SERS) detection polycyclic aromatic hydrocarbons (PAHs). VGDs are able to form intermolecular cavities at interparticle junctions (SERS hot spots) where analyte can be allocated. This leads a giant intensification emission target molecule. effect was applied PAHs, one most widespread and dangerous group pollutants...

This work reports on the formation of different types structures surface polymer films upon UV laser irradiation. Poly(ethylene terephthalate) was irradiated with nanosecond pulses at 193 and 266 nm. The polarization beam irradiation angle incidence were varied, giving rise to induced shapes periodicities. surfaces topographically characterized by atomic force microscopy chemical modifications inspected via micro-Raman fluorescence spectroscopies. Contact measurements performed liquids,...

In this work we present the formation of laser induced periodic surface structures (LIPSS) on spin-coated thin films several model aromatic polymers including poly(ethylene terephthalate), poly(trimethylene terephthalate) and poly carbonate bis-phenol A upon irradiation with femtosecond pulses 795 265 nm at fluences well below ablation threshold. LIPSS are formed period lengths similar to wavelength parallel direction polarization vector. Formation IR nm, a which absorb weakly, contrasts...

Abstract FT‐Raman and surface‐enhanced Raman scattering (SERS) spectroscopy were applied in the vibrational characterization study of adsorption acidity behavior highly fluorescent anthraquinone dye alizarin on Ag colloids prepared by chemical reduction with hydroxylamine hydrochloride. The SERS spectra obtained at different conditions pH, excitation wavelength pigment concentration order to deduce mechanism this molecule. On basis results found we propose an model for alizarin, which has a...

Surface-enhanced infrared (SEIR) and surface-enhanced Raman scattering (SERS) spectroscopies are applied to the study of adsorption on Au films dimethyldithiocarbamate derivative fungicides thiram ziram. The specificity sensitivity both techniques in relation detection surface stability above compounds is analyzed comparatively. We have found that undergo a breakdown when adsorbed films, although this takes place different extent; seems be less stable than higher, lower enhancement SERS...

Trace concentrations of polycyclic aromatic hydrocarbons (PAHs) have been successfully detected using surface-enhanced Raman scattering (SERS) spectroscopy. For such purpose, new SERS substrates developed, consisting Ag nanoparticles, either in suspension or immobilized on glass, obtained by a method and covered adsorbed self-assembled calix[4]arene molecules. Among the assayed calix[4]arenes, 25,27-dicarboethoxy-26,28-dihydroxy-p-tert-butylcalix[4]arene host molecule displays analytical...

We report the use of 25,27-diethyl-dithiocarbamic-26,28-dihydroxy-p-tert-butylcalix[4]arene in functionalization Ag nanoparticles for pyrene detection by surface-enhanced Raman scattering (SERS). SERS spectra provided information about calixarene orientation on metal surface and interaction mechanism with pyrene. Thus, this work, we have combined a powerful spectroscopy technique such as SERS, electronic plasmon-based properties nanostructured metals, molecular size-selective recognition...

Abstract Alizarin and carminic acid have been detected in reference wool linen fibers dyed with madder cochineal, respectively, through surface‐enhanced Raman scattering (SERS) measurements carried out directly on the fiber , without previous hydrolysis of mordant‐dye complex. For such purpose, Ag nanoparticles were produced immobilized situ via laser photoreduction a silver nitrate aqueous solution contact fiber. Control SERS spectra pure dyes (alizarin, purpurin acid, as well mixtures...

In this Letter, we report on the successful fabrication of low loss, high refractive index contrast waveguides via ion migration upon femtosecond laser writing in phosphate glass. Waveguides were produced two different glass compositions with and La(2)O(3) content. La-rich glass, a large increase guiding region was observed due to incoming La accompanied by out-diffusion K. The much smaller change La-less is caused rearrangements structure. These results confirm feasibility adapting...

The surface-enhanced Raman scattering (SERS) spectra of a group flavonoids with related structures (quercetin, kaempferol, luteolin and apigenin) are reported here for the first time. It is demonstrated that studied undergo chemical change on Ag nanoparticles prepared by reduction citrate used as SERS substrate. Two labile groups have been identified, one them corresponding to catechol-like moiety another C-ring, when hydroxyl in position α respect keto group. Copyright © 2006 John Wiley & Sons, Ltd.

Abstract The long‐term hydration of white portland cement has been followed through micro‐Raman spectroscopy, choosing for excitation the most adequate laser wavelength as deduced from a critical analysis previously reported Raman data. bands corresponding spectra were attributed to various anhydrous and hydrated phases, with full phases taking place after 180 days. Sulphoaluminates seen form in two different local environments, at 3 days respectively. Carbonates, secondary reaction product,...

Paramolybdate-LDHs with MgAl or ZnAl cations within the layers have been prepared by ion-exchange method from hydrotalcites different interlayer anions (OH-, NO3(-), and terephthalate). The samples oxides obtained after their calcination were characterized element chemical analysis, PXRD, FT-Raman spectroscopy, thermal analysis (TG/DTA), N2 adsorption at -196 degrees C, SEM. results show that layered solids hydrotalcite-type structure in which space is occupied heptamolybdate a small amount...

In this work surface-enhanced resonance Raman spectroscopic experiments have demonstrated that metallic single-walled carbon nanotubes can be used as chemical assemblies between the pyrene analyte and silver colloidal surface. Pyrene has been detected at concentrations lower than 10(-9) M by use of 514.5 nm excitation laser line. A charge transfer from surface to nanotube characterizes nanotube-silver interaction. The pyrene-nanotube interaction occurs through a pi-pi electronic stacking....

The application of viologen dications in the creation highly sensitive and selective hot spots between silver nanoparticles is reported present work. A method to follow existence such macroscopic samples proposed based on plasmon absorption these suspension. was applied case detection polycyclic aromatic hydrocarbon pyrene, confirming great ability viologens, increasing sensitivity selectivity SERS technique, as both spot inducers host molecules.

Abstract The absolute Raman intensities and depolarization ratios of all the fundamental bands CH2Cl2, CD2Cl2 CHDCl2 have been measured in gas phase. These experimental data included a refinement vibrational potential function dichloromethanes. A detailed description is made use bond polarizability approach. Explicit expressions for derivatives molecular with respect to symmetry coordinates are given terms zeroth- first-order electro-optical parameters theory. Good agreement found between...