Wyniki wyszukiwania - BazTech

1

Innowacyjne detektory gazów zbudowane z warstw NW-Ni-Pd i C-Ni-Pd

Stępińska I., Czerwosz E., Diduszko R., Kozłowski M., Wronka H., Rymarczyk J., Krawczyk S.

Elektronika : konstrukcje, technologie, zastosowania

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2017

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Vol. 58, nr 12

60--66

PL

W artykule przedstawiono badania pod względem struktury materiałów przeznaczonych na innowacyjne detektory gazowe. Materiały te bazują na nanorurkach węglowych (NW), nanokrystalitach Pd i nanokrystalitach Ni. Materiały te otrzymywane są w postaci warstw przygotowanych w wielokrotnych procesach PVD, CVD. Nasze badania elektrono-mikroskopowe, FTIR oraz rtg pokazały strukturę tych materiałów zarówno krystaliczną jak i molekularną. Pokazano też wyniki pomiarów odpowiedzi tych warstw na wodór przy różnych jego stężeniach.

EN

The paper presents the investigations of the structure of materials for innovative gas detectors. These materials are based on carbon nanotubes (CNT), Pd nanocrystalite and Ni nanocrystallite. These materials are obtained in the form of films prepared in multiple PVD and CVD processes. Our electron microscope, FTIR and X-ray studies have shown the structure of both crystalline and molecular materials. The results of measurements of the response of these films to such hydrogen gas at various concentration were also presented.

2

Chemical degradation of PCDD/F in contaminated sediment

Hrabák P., Homolková M., Wacławek S., Černík M.

Ecological Chemistry and Engineering. S

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2016

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Vol. 23, nr 3

473--482

EN

Due to the extreme toxicity of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F), the remediation of PCDD/F aquifer source zones is greatly needed; however, it is very difficult due to their persistence and recalcitrance. The potential degradability of PCDD/F bound to a real matrix was studied in five systems: iron in a high oxidation state (ferrate), zero-valent iron nanoparticles (nZVI), palladium nanopowder (Pd), a combination of nZVI and Pd, and persulfate (PSF). The results were expressed by comparing the total toxicity of treated and untreated samples. This was done by weighting the concentrations of congeners (determined using a standardized GC/HRMS technique) by their defined toxicity equivalent factors (TEF). The results indicated that only PSF was able to significantly degrade PCDD/F. Toxicity in the system decreased by 65% after PSF treatment. Thus, we conclude that PSF may be a potential solution for in-situ remediation of soil and groundwater at PCDD/F contaminated sites.

3

Properties of Pd nanograins in C-Pd composite films obtained by PVD method

Kozłowski M., Czerwosz E., Radomska J., Sobczak K., Dłużewski P. A.

Materials Science Poland

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2015

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Vol. 33, No. 3

482--487

EN

Properties of palladium nanograins obtained by sedimentation of a soluted C-Pd film prepared by PVD method are presented. These properties were studied using SEM and TEM methods. Dissolved films were prepared by PVD method and after dissolving, they were fractionated to obtain different parts classified with palladium nanograins diameters. Several classes of diameters were determined: below 20 nm, between 20 and 100 nm and above 100 nm. The defects and triple junction were observed. Multishell carbonaceous structures were found in the big and medium size Pd nanograins.

4

Annealing time effects on the surface morphology of C–Pd films prepared on silicon covered with SiO2

Kozlowski M., Radomska J., Wronka H., Czerwosz E., Firek P., Sobczak K., Dluzewski P.

Optica Applicata

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2013

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Vol. 43, nr 1

81--89

EN

Morphology changes of C–Pd films prepared in physical vapor deposition (PVD) process and next annealed in a temperature of 650 °C during different time were studied. These studies were performed with electron microscopy methods (scanning SEM and transmission TEM). It was found that not annealed films are flat and they are composed of grains with composite character and size of 100–200 nm. Pd nanocrystallite of a diameter of a few nanometers in some carbon matrix was placed in these grains. For annealed films, a formation of palladium nanograins with different sizes and shapes as well as a porous carbon matrix were observed. High resolution TEM investigation was used to determine a structure of all these grains. An increase in duration time of annealing process led to diminishing of the porosity of carbon matrix and a number of Pd grains situated on the film surface. It was also stated that covering of Si with SiO2 layer prevents formation of palladium silicide.

5

Badania struktury molekuralnej i nanokrystalicznej warstw Pd-C do zastosowań w detektorach wodorowych

Suchańska M., Czerwosz E., Diduszko R., Dłużewski P., Kęczkowska J., Kowalska E., Rymarczyk J.

Elektronika : konstrukcje, technologie, zastosowania

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2010

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Vol. 51, nr 6

54-57

PL

Prezentowane są wyniki charakteryzacji właściwości fizyko-chemicznych nanostrukturalnych warstw węglowo-palladowych (Pd-C), które mogą być wykorzystane jako warstwy aktywne w detektorach wodoru i/lub związków gazowych wodoru. Warstwy Pd-C zostały wytworzone metodą dwuetapową, gdzie jako pierwszy etap zastosowano technologie PVD, zaś drugim etapem byta metoda CVD. Badano topografię warstw metodą mikroskopii sił atomowych (AFM). Struktura warstw była badana na poziomie subatomowym metodą transmisyjnej mikroskopii elektronowej (TEM), w skali molekularnej metodą spektroskopii ramanowskiej (RS), a w skali mikro metodą dyfrakcji rentgenowskiej (XRD).

EN

Pd-C films are known as very promising materials for hydrogen sensors and storage. We present results of characterization of Pd-C films composed of carbon and palladium nanograins and obtained in two steps method. The film obtained in the first step exhibits multiphase structure composed of fullerene nanograins, amorphous carbon and palladium nanocrystals. This film is modified in CVD process. The final films has porous carbonaceous structure. The films topography was studied using Atomie Force Microscopy (AFM). The films structure was investigated using the following methods: Transmission Electron Microscopy (TEM) on subatomic level, Raman Spectroscopy (RS) in molecular scale and X-ray Diffraction (XRD) in micro scale.

6

Removal of nitrogen oxides over catalyst by changing exhaust gases composition

Księżopolska M., Darkowski A., Raróg-Pilecka W., Dłuha D.

Journal of KONES

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2006

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Vol. 13, No. 3

179-186

EN

The influence of addition of potassium or barium to Pd/Al2O3 catalyst on the catalytic performance of nitrogen oxides storage-reduction catalyst was studied. The catalysts: Pd-K-Al2O3, Pd-Ba-Al2O3and Pd-K/Ba-Al2O3 were prepared by impregnation method. Alumina spheres contained Pd=1 and 4 %, K=10%, and/or Ba=10%. The conversions of nitrogen oxides as function of fuel mixture composition were determined. Studies were carried at the temperature range 200-500oC. The influence of addition of potassium and barium to catalyst on its storage-reduction nitrogen oxide activity was considered. The highest conversion of NOx was obtained for Pd(4%)-K-Al2O3 catalyst. Results show that the highest conversion of NOx was obtained for Pd(4%)-K-Al2O3 catalyst it could be caused with different structure of catalyst surface. For all catalysts, during periodic changes of lean to rich mixture, NOx conversion is high during lean condition and is falling during rich condition and is later increasing repeatedly. catalysts composition influences the temperature range in which its activity is the highest. On the base of studied data conversion of NOx there was observde that catalysts composition influences the temperature range in which its activity is the highest. Although dispersion of palladium decreases when its concentration increases, a fall of nitrogen oxide conversion for catalysts containing higher concentration of palladium does not occur.