Wyniki wyszukiwania - BazTech

1

Comparison of photoacoustic, diffuse reflectance, attenuated total reflectance and transmission infrared spectroscopy for the study of biochars

Pasieczna-Patkowska S., Madej J.

Polish Journal of Chemical Technology

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2018

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Vol. 20, nr 4

75--83

EN

Four infrared spectroscopic techniques - photoacoustic (PAS), diffuse reflectance (DRS), attenuated total reflectance (ATR) and transmission (TS) - were evaluated for the qualitative analysis of the biochar obtained from willow feedstock during pyrolysis. Increase in pyrolysis temperature resulted in more aromatic and carbonaceous structure of biochars. These changes could easily be detected from Fourier transform infrared (FT-IR) spectral differences. The comparison of the spectra obtained by the four FT-IR techniques allowed to conclude that there are differences in the spectra acquired using different IR technique caused by different signal acquisition. PAS and ATR were the best techniques used in order to obtain spectra with smooth and sharp peaks, in contrast to TS, where bands were less-separated. DRS turned out to be the weakest of all techniques, due to poor spectral quality and poor separation of the bands.

2

Phenol and methylene blue photodegradation over Ti/SBA-15 materials under uv light

Olejnik T., Pasieczna-Patkowska S., Lesiuk A., Ryczkowski J.

Polish Journal of Chemical Technology

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2016

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Vol. 18, nr 3

30--38

EN

Ordered SBA-15 mesoporous silica supports have been synthesized and used for incorporation of titanium with different Ti/Si weight ratio via incipient wetness impregnation. Titanium tetraisopropoxide (TTIP) was used as a source of Ti. Obtained catalysts were characterized to investigate the chemical framework and morphology by nitrogen sorption measurements, powder X-ray diffraction (XRD), X-ray fluorescence elemental analysis (XRF), transmission electron microscopy (TEM), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS) and Fourier transform infrared photoacoustic spectroscopy (FT-IR/PAS). The photocatalytic degradation of phenol and methylene blue water solutions were selected as a probe reactions to the photoactivity test of prepared samples and to verify the potential application of these materials for water purification. Experimental results indicate that the photocatalytic activity of Ti/Si mixed materials depends on the adsorption ability of composites and the photocatalytic activity of the titanium oxide.

3

Ocena rozkładu handlowych opakowań polietylenowych w glebie metodą FT-IR/PAS

Pasieczna-Patkowska S., Lesiuk A.

Chemik

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2013

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Vol. 67, nr 10

863--872

PL

Opisano badania, których celem była ocena stopnia degradacji wybranych handlowych opakowań polietylenowych zawierających prooksydanty, użytkowanych wcześniej przez konsumentów. Po użyciu opakowania zostały umieszczone w różnych rodzajach gleb (las, łąka, pole rolne, ugór). Stopień ich degradacji oceniano na podstawie analizy widm FT-IR/PAS. Dla określenia wpływu czynników środowiskowych na degradację badanych tworzyw zbadano pH, wilgotność oraz zawartość materii organicznej w glebach. Jednym z ważniejszych czynników wpływających na stopień degradacji jest ilość i rodzaj dodatków zastosowanych przy produkcji tworzywa. Badane opakowania najlepiej rozkładają się w warunkach naturalnych, w glebie intensywnie użytkowanej (pole rolne).

EN

The aim of the research was to estimate the degree of biodegradation of the chosen biodegradable commercial packaging containing pro-oxidants, previously used by consumers and after usage placed in natural conditions. They were placed in four types of soil (forest, meadow, arable field, fallow). The extent of polyethylene degradation was examined by means of FT-IR/PAS method. In order to determine what effect environmental factors have on plastic degradation in natural conditions, pH, humidity and amount of organic matter in soil were examined. The appearance of oxygen bands in FT-IR/PAS spectra in all the presented cases indicates polyethylene degradation. The more important factor affecting degradation level is the amount and kind of supplementation used at plastic manufacturing. The best conditions for decomposition of packaging in natural conditions are guaranteed by soil that is intensely used.

4

Synthesis and Characterization of Bimetallic Ag-Mn-MCM-41 Materials

Deryło-Marczewska A., Gac W., Popivnyak N., Żukociński G., Pasieczna-Patkowska S.

Polish Journal of Chemistry

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2008

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Vol. 82, nr 1-2

263-270

EN

The series of mesoporous, bimetallic Ag-Mn-MCM-41 materials were synthesized by applying direct synthesis and ion-exchange methods. Their surface and structure characteristics were analyzed using nitrogen adsorption/desorption isotherms, XRD data, FT-IR/PA spectrometry, and temperature programmed reduction. The differences between the porous structure and the forms of metallic species formed in the structure and on the silica surface were found for the materials synthesized by direct synthesis and ion-exchange method.