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1

Enhancement of XPS surface sensitivity in nanocrystalline material

100%

Wróbel R.

Polish Journal of Chemical Technology

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2010

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vol. 12

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issue 4

62-63

EN

The influence of the particle size on the surface sensitivity in XPS analysis was investigated. Previous reports about such influence were qualitatively only. In this report there are given mathematical description of XPS sensitivity and quantitative results. It was found that influence due to nanometric size on XPS analysis can be noticeable for particles below 15 nm of diameter and increases dramatically with reduction of the size.

2

Low pressure RF plasma modification of the surface of three different nano-carbon materials

100%

Bertóti I., Mohai M., Balázsi C., László K., Szépvölgyi J.

Open Chemistry

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2015

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vol. 13

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issue 1

EN

Well-ordered nano-carbon materials, like multi-wall carbon nanotubes, graphene oxide, graphene due to their unique physical and chemical properties, are candidates for promising applications. In this work thin multilayered graphene, single layer graphene oxide layers and highly oriented pyrolytic graphite (HOPG) surface were treated by RF activated N2 gas plasma at nominally room temperature. Negative bias in the 0–200 V range and treatment time of 10 min was applied. Surface chemical alterations were followed by X-ray photoelectron spectroscopy (XPS). The applied treatments resulted in a significant build-up of nitrogen in the surface of these nano-carbon materials. The amount of nitrogen varied between 4 and 10 atomic %, depending on type of carbon and on biasing conditions. Evaluating the high-resolution N1s XP spectral region, typically three different chemical bonding states of the nitrogen were delineated. Peak component at 398.3 eV is assigned to C=N–C type, at 399.7 eV to sp2 N in melamine-type ring structure and at 400.9 eV to N substituting carbon in a graphite-like environment. Identical chemical bonding of the nitrogen was detected on the surface of HOPG treated in the same way for comparison.

3

XPS Study of group IA carbonates

100%

Shchukarev A., Korolkov D.

Open Chemistry

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2004

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vol. 2

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issue 2

347-362

EN

The results of systematic XPS measurements of all alkali metal carbonates (Li, Na, K, Rb and Cs) are presented. The first set of experiments was performed with “as received” commercial carbonate powders under liquid nitrogen conditions using a precooling procedure. A second set of experiments was performed under similar experimental conditions after a preliminary grinding (mechanical activation) of the carbonates. In addition, Na2CO3 *1H2O, NaHCO3 and KHCO3 powders were studied. It was found that sample pre-cooling allows distinction between hydrocarbonates and carbonate hydrates. Storage in air leads to formation of hydrocarbonates at the surface of Li2CO3 and Na2CO3. This phenomenon being more pronounced in the former. In contrast, K2CO3 forms a hydrate with one H2O molecule. Rb2CO3 and Cs2CO3 have hydrocarbonates as well as hydrates at the surface and this is more pronounced for Cs2CO3. Grinding of the carbonates results in the formation of hydrocarbonates at the surface, the tendency to do so was found to increase down the group IA, namely, K

4

Depth Analysis of Crystalline Silicon Used for Radiation-Hard Detectors

100%

Moloi S., McPherson M.

Acta Physica Polonica A

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2017

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vol. 132

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issue 4

1387-1392

EN

Depth analysis of metal-doped crystalline silicon by the X-ray photoelectron spectroscopy technique is presented in this work. The results from this technique are used to complement those from previous techniques. The metals diffused into the silicon are gold, platinum, erbium, and niobium. In silicon, these metals induce defects that are responsible for relaxation behaviour of the material. Relaxation material is radiation-hard since the effects of radiation on devices fabricated on the material are suppressed. Considerable amounts of gold, platinum, and niobium are found in the silicon bulk. The results of this work are in good agreement with those reported earlier on the same samples using the Rutherford backscattering technique. The spectra of the natural contaminants, carbon and oxygen, are also analysed in this work.

5

Supplementary research of clinoptilolite-rich tuff composites after adsorption trials using the XPS technique

88%

Chmielewská E., Tylus W., Morvová M.

Open Chemistry

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2006

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vol. 4

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issue 1

1-12

EN

The paper deals with fabrication of carbonized and hydrophobized clinoptilolite-rich tuff using organic carbon rich substances, here particularly starch and waste vegetable residues, which were pyrolytically combusted and covered the external zeolite surface. Hydrophobization of the zeolite external surface was accomplished by octadecylammonium surfactant. Both surface modified clinoptilolite-rich tuffs were tested and compared with each other with regard to removal of organic (phenol) and inorganic (chromate, arsenate) pollutants from aqueous solutions. These elaborated composites with surface adsorbed pollutant species were analysed by X-ray photoelectron spectroscopy (XPS).

6

Atmospheric pressure plasma treatment of polyamide-12 foils

88%

Hanusová J., Kováčik D., Stupavská M., Černák M., Novák I.

Open Chemistry

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2015

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vol. 13

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issue 1

EN

The surface of a polyamide-12 (PA-12) foil was modified in order to improve the adhesive properties by two types of atmospheric pressure plasma sources. The samples were characterized using contact angle measurement, adhesive properties measurement and X-ray photoelectron spectroscopy (XPS). The ageing of the plasma modification was also studied. A significant increase in wettability was observed at different treatment times. The same effect was also seen in the adhesive properties - the adhesion was increased almost 12 times for 10 s DCSBD treatment in comparison to untreated PA-12. XPS analysis confirmed chemical changes due to the plasma modification of the PA-12. It was concluded that both plasma sources improve the adhesive properties of PA-12, with DCSBD obtaining better results.

7

Comparison characterization of copper selenide thin layers prepared on polyamide 6 films by sorption-diffusion method

88%

Ivanauskas R., Janickis V., Jasulaitienė V.

Open Chemistry

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2013

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vol. 11

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issue 4

636-643

EN

Some earlier synthesized copper selenide (Cux Se) layers formed on the surface of polyamide 6 by sorption-diffusion method using potassium selenotrithionate (K2SeS2O6) as precursor of selenium were characterized by the XRD, XPS and SEM methods. According to the results of the SEM studies, the most uniform Cux Se layers form at the 2.5 h polyamide seleniumized duration at the temperature of 60°C. The thickness of layers, which dependeds on the duration of seleniumization, changed in the range of 0.8–3.2 µm. The XRD patterns of not previously studied Cux Se layers showed their phase composition of six copper selenides: Cu2Se, two phases of CuSe2, Cu3Se2, berzellianite, Cu2-x Se, and bellidoite Cu2Se. Analysis of the XRD and XPS data shows that the macrostructure and composition of the CuxSe layers depend on the conditions of formation of these layers. [...]

8

Study by grazing incident diffraction and surface spectroscopy of amalgams from ancient mirrors

88%

Herrera L., Duran A., Franquelo M., González-Elipe A., Espinós J., Rubio-Zuazo J., Castro G., Justo A., Perez-Rodriguez J.

Open Chemistry

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2009

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vol. 7

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issue 1

47-53

EN

Characterization of four amalgam surfaces, with different alteration degrees from Andalusia historical mirrors, has been carried out by grazing-incidence X-ray diffraction (GIXRD), and other spectroscopic techniques (SEM/EDX, XPS, and REELS). The combination of all these techniques allows determining the corrosion state of the amalgams. The results show that the amalgams are composed in all cases of a binary alloy of tin and mercury. As mercury has high vapour pressure at RT, it slowly segregates and eventually evaporates, it leaves finely divided particles of tin that easily can be oxidize, forming tin monoxide (SnO) and tin dioxide (SnO2). In one of the samples, most of the amalgam remains unoxidized, since Hg0.1Sn0.9 and metallic Sn phases are the major components; in two other samples, Hg0.1Sn0.9 and Sn phases are not detected while SnO2 and SnO phases appear. Finally, in the last studied sample, only SnO2 phase is detected. The surface analyses of these samples by XPS show that, for most of them an unique chemical species (Sn4+) is found. [...]

9

Application of X-ray photoelectron spectroscopy (XPS) and a functional near infrared spectroscopy (fNIRS) in medicine

88%

Szklarczyk M.

European Journal of Translational and Clinical Medicine

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2021

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vol. 4

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issue 2

86-93

EN

The development of modern clinical medicine and the truthful medical diagnosis require hard physicochemical data. Furthermore, the social demands for more accurate and collected data, which refer to human health in real conditions and in real time, force the quest for techniques which would be possible to be applied in a broadly understood clinical field. In this article two techniques are described. A high vacuum technique which is an X-ray photoelectron spectroscopy (XPS), and a functional near infrared spectroscopy (fNIRS), which might be applied in vivo condition. For the both techniques, the results pointing their applicability in the clinical and modern biochemical research are described.

10

The effect of preparation method on the performance of PtSn/Al2O3catalysts for acetic acid hydrogenation

88%

Zhang K., Zhang H., Ma H., Ying W., Fang D.

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EN

PtSn/Al2O3 catalysts with a given loading of 1 wt% Pt and 1 wt% Sn were prepared by co-impregnation or successive impregnation with aqueous solutions of Pt, Sn precursors and a commercial alumina. The catalysts were characterized by N2 adsorption, H2-TPR (H2 temperature-programmed reduction), H2-pulse chemisorption, XPS (X-ray photoelectron spectroscopy) and CO-FTIR (Fourier transform infrared spectroscopy), and tested in the hydrogenation of acetic acid. The results showed that the preparation method affected both the chemical properties and their performance in the hydrogenation of acetic acid. Sn enrichment on the catalysts surface was observed on the co-impregnated catalyst and catalyst in which the Pt precursor had been loaded first. It was found that the modification of Pt was a function of the sequence of Sn addition as revealed by CO-FTIR. Co-impregnated catalyst showed the highest activity and ethanol selectivity.

11

Synthesis, morphology and specific magnetization of the electrodeposited Zn-Ni-P thin films on copper substrate from non-cyanide electrolyte

75%

Popescu A., Yanuskevich K., Demidenko O., Calderon Moreno J., Neacşu E., Constantin V.

Open Chemistry

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2013

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vol. 11

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issue 7

1137-1149

EN

Thin films of Zn-Ni-P on a copper substrate were synthesized by electrodeposition from chloride baths. It was found that the diffraction reflections of the crystal structure of Zn-Ni-P thin layers occur at thicknesses d ≥ 5 µm. The X-ray diffraction studies results confirm the formation in the Zn-Ni-P films of ZnNi10P3 compound. The morphology of the obtained films was analyzed by Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectrometry (EDS). The films are continuous and have a typical topography with many homogeneous globular features. EDS confirmed the formation of Zn-Ni-P coating only in 2 samples with Zn:Ni:P atomic ratios of 1:8:4 and 4:8:3, respectively. X-ray Photoelectron Spectroscopy (XPS) revealed the chemistry and the thickness of the studied thin films. At room temperature and thickness d ≥ 5 µm the investigated thin layers exhibit high values of the specific magnetizations in the range (25–37) A m2 kg−1, leading to the potential use in devices, appliances and electronics. The Curie temperature values of the synthesized Zn-Ni-P films were determined. It was found that by heating Zn-Ni-P thin layers of thicknesses d ≥ 5 µm up to a temperature T=900 K an interaction was detected with the copper substrate leading to a lower specific magnetization. [...]

12

Effect of surfactants on the flotation performance of low-rank coal by particle sliding process measurements

75%

Wang S., Tao X.

Gospodarka Surowcami Mineralnymi

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2018

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vol. 34

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issue 1

Refine search results

Enhancement of XPS surface sensitivity in nanocrystalline material

Low pressure RF plasma modification of the surface of three different nano-carbon materials

XPS Study of group IA carbonates

Depth Analysis of Crystalline Silicon Used for Radiation-Hard Detectors

Supplementary research of clinoptilolite-rich tuff composites after adsorption trials using the XPS technique

Atmospheric pressure plasma treatment of polyamide-12 foils

Comparison characterization of copper selenide thin layers prepared on polyamide 6 films by sorption-diffusion method

Study by grazing incident diffraction and surface spectroscopy of amalgams from ancient mirrors

Application of X-ray photoelectron spectroscopy (XPS) and a functional near infrared spectroscopy (fNIRS) in medicine

The effect of preparation method on the performance of PtSn/Al2O3catalysts for acetic acid hydrogenation

Synthesis, morphology and specific magnetization of the electrodeposited Zn-Ni-P thin films on copper substrate from non-cyanide electrolyte

Effect of surfactants on the flotation performance of low-rank coal by particle sliding process measurements