Electron spectroscopic investigation of Sn coatings on glasses

Float glasses of different thicknesses and a conducting tin oxide glass have been investigated using Photo and Auger Electron Spectroscopy induced by AlKα X-rays. On the basis of measured chemical XPS shifts in the binding energies the chemical state of Sn (+2 or +4) incorporated on the float glasses could not be assigned. The use of the Auger parameter allows to separate relaxation and chemical contributions. The derived true chemical shifts of Sn on float-glasses are larger than those of SnO and/or SnO2 due to the larger ionic environment of the glass matrix. Ar+ or HF etching reveals that the concentration of Sn decreases exponentially as a function of depth from the surface. © Springer-Verlag 1996

X-ray photoelectron spectroscopic investigation of conducting polymer blends

Electrochemically prepared films of conducting polymers of polypyrrole and polythiophene and their blends with polyamide have been investigated by X-ray photoelectron spectroscopy. In the N1s region of the spectra of films containing polypyrrole the peak corresponding to N+ at 402.0 eV is separated from that of neutral N. The intensity of the N+ peak can be correlated with the electrical conductivity of the films and the spectroscopically derived ratio of F/N+ is close to 4 indicating that one BF4 - dopant ion is incorporated for every oxidized nitrogen center. In the spectra of films of polythiophene and its blends peaks corresponding to S and S+ can not be resolved but again the F/C ratio correlates with the electrical conductivity. © Springer-Verlag 1996

Surface spectroscopic studies of Cs+, and Ba2+ sorption on chlorite-illite mixed clay

The sorption behavior of Cs+, and Ba2+ on natural clay was investigated using ToF-SIMS, XPS, and XRD. The natural clay was composed mainly of chlorite and illite in addition to quartz and calcite. Depth profiling up to 70 Å was performed at 10 Å steps utilizing ToF-SIMS to study the amount of sorbed Cs+ and Ba2+ as a function of depth in the clay matrix. The results suggest that Cs+ and Ba2+ ions were sorbed primarily by ion exchange coupled with hydrolytic sorption. According to ToF-SIMS and XPS results, the total sorbed amount of Ba2+ was larger than that of Cs+. Quantitative determination of the primary cations within the analyzed clay before and after sorption indicated that for Ba2+ sorption, Ca2+, Mg2+ and for Cs+ sorption Ca2+, K+ were the major exchanging ions. The XRD spectra of Ba-sorbed clay contained new peaks that were identified as BaCO3

XPS studies of MCM 41 postmodified by a Schiff base copper complex

Preliminary studies of the distribution of the copper complex in MCM 41 postmodified by a Schiff base (salen) copper complex have been carried out using x-ray photoelectron spectroscopy (XPS) and atomic absorption spectroscopy (AAS). AAS showed 1.3 at% (atomic %) (0.65 mmolg(-1)) of copper loading, which is in close agreement with 1.5 at% obtained from XPS analysis. Nitrogen sorption (77 K) shows a change from a Type IV to a Type I isotherm on postmodification, indicating a change in porosity of the material from mesoporous to microporous. This change in porosity corresponds to a reduction in surface surface area (from 813 m(2)g(-1) to 332 m(2)g(-1)) and pore volume (from 0.39 cm(3)g(-1) to 0.02 cm(3)g(-1)). The XPS argon ion etching results suggest that about a third of the copper complex is going inside the pores, thereby narrowing some pores and blocking others. The remaining copper complex goes on to the external surface of the material. This hypothesis is consistent with the observed changes detected by nitrogen sorption studies on postmodification of MCM 41

A photoelectron spectroscopic investigation of conducting polypyrrole-polyamide composite film

X-ray photoelectron spectrum of the electrochemically prepared polypyrrole and polypyrrole-polyamide composite films exhibit an additional strong high binding energy peak at 402.0 eV corresponding to N+ moieties. Intensity of this peak is significantly reduced upon electrochemical reduction. Atomic concentrations derived from the observed N+ and F (stemming from the dopant BF4-) peaks reveal a slightly higher cation/anion ratio for this composite and suggest that the composite has a different chemical composition than the corresponding polymers. © 1995 Elsevier Science B.V