Czesława Paluszkiewicz

FT-IR and FT-Raman study of hydrothermally degradated cellulose

Abstract Deterioration of books and archive materials is due to degradation of cellulose that is caused by many factors such as acidic hydrolysis, oxidative agents, light, air pollution or presence of microorganisms. Recently, FT-IR and FT-Raman spectroscopy have been used for the characterization of cellulose and its degradation products. In this work, we present vibrational spectra obtained with different sampling techniques of pure cellulose from softwood and cotton that has been hydrothermally treated for maximum 21 days in extreme humid atmosphere (100% humidity, 100°C). We show that the obtained results strictly depend upon spectroscopic techniques used in measurements. We also present and discuss changes in vibrational spectra pointing out a role that is played by water molecules in this accelerated aging process of paper.

The FTIR spectroscopy and QXRD studies of calcium phosphate based materials produced from the powder precursors with different CaP ratios

Abstract Six precipitates of calcium phosphates with Ca P molar ratios in the range of 1.502–1.717 have been prepared by the wet method. After shaping and sintering at 1250 °C the phase composition of the obtained materials was examined by QXRD and FTIR spectroscopy methods.

FTIR study of degradation products of aliphatic polyesters–carbon fibres composites

Abstract Biodegradable polymer composites based on polylactides and polyglycolides constitute a group of materials characterised by good biocompatibility. They are considered in tissue engineering as scaffolds for cells proliferation and controlled tissue regeneration. Two types of biodegradable polymers possessing different chemical structure, molecular weights and crystallinity degrees and two composite materials made up of them and carbon fibres were analysed in this study. The samples were incubated in aqueous media for 8 weeks and analysed by means of Fourier transform infrared spectroscopy in the attenuated total reflection mode (FTIR-ATR). Infrared spectroscopy enabled identification of degradation products and estimation of the influence of carbon fibres on hydrolytic degradation of analysed polymers. Analysis of the infrared spectra showed that hydrolytic degradation process depends on chemical structure, molecular weight and crystallinity of polymers. Catalytic effect of carbon fibres at the initial stage of polymer degradation was observed. Further degradation is dependent on the properties of polymer.

Infrared and Raman studies of palladium—nitrogen-containing polymers interactions

In the present research the nature of interactions of poly(4-vinylpyridine) (PVP) and polyaniline (PANI) with various Pd 21 chlorocomplexes existing in PdCl2‐HCl‐H 2O solutions have been studied using IR (MIR, FIR) and Raman spectroscopies. It has been found that these interactions involve the nitrogen atoms of the polymers. In the PdCl 2 solutions of high HCl concentration containing [PdCl4] 22 and [PdCl3(H2O)] 2 as the major species acid‐base type reaction (protonation) with the formation of the polymer salt as well as the coordination of Pd 21 ions by the nitrogen atoms of the polymer take place. In the PdCl2 solutions of low HCl concentration containing [PdCl2(H2O) 2] as the major species protonation proceeds to a small extent. The main process in this case is most probably hydrolysis of the latter with the precipitation of hydrated palladium hydroxide or oxide on the polymer surface. In the case of PANI the oxidation‐reduction between this precipitate and PANI takes place. It results in the oxidation of the polymer chain. q 1999 Elsevier Science B.V. All rights reserved.

Analysis of human cancer prostate tissues using FTIR microspectroscopy and SRIXE techniques

Abstract It is known that Fourier transform infrared (FTIR) spectra of human tissues are specific and can be used to discriminate between various disease states. In this study, cancer and healthy parts of prostate tissues were examined. The human prostate tissues were obtained during surgical operation. Sections of samples were mounted onto Mylar foils and measured by both FTIR microspectroscopy and synchrotron radiation induced X-ray emission (SRIXE) methods. Neighboring sections of tissues analyzed by FTIR and SRIXE were also examined by a histopathologist. Since the SRIXE technique is suitable for trace element analysis the two-dimensional scans on both cancerous and non-cancerous parts of the prostate tissues were done in order to find elemental distribution of trace elements. The single point analysis on selected areas were also performed. Then the same samples were studied in the mid infrared region on Excalibur spectrometer with infrared microscope UMA-500 equipped with an automatic xy-stage and video camera. Both FTIR spectra and elemental distribution show differences between cancerous and non-cancerous parts of the analyzed tissues.

Renal stone studies using vibrational spectroscopy and trace element analysis

Urolithiasis is a disease that has been studied for many years, and the ethiopathogenesis of stone formation is not well understood. It is therefore important to fully recognize both the stones chemical structure and composition. The structural composition of renal stones was determined by Fourier transform infrared spectroscopy and Fourier transform Raman spectroscopy. The elemental composition was determined by means of proton-induced X-ray emission, and the lead concentration was confirmed using atomic emission spectroscopy. Because of varying calculi composition, it was convenient to divide the stones into six groups: magnesium ammonium phosphate hexahydrate (struvite), calcium phosphate (apatite), mixed phosphates and oxalates, calcium oxalate mono- and dihydrate (whewellite and wedellite), mixed oxalates and uric acid, and uric acid. Trace elements interact with the bodys organs and thus play a significant role in the living processes. It is important to establish concentration levels in analyzed materials. Such information can help in the diagnosis and evaluation of the risk of stone formation. Therefore, the concentration of trace elements in the samples has been determined. The correlation between lead concentration and structural composition and the correlation between lead concentration and environmental influence were found. The results obtained were statistically analyzed.

FTIR In Situ Studies of the Gas Phase Reactions in Chemical Vapor Deposition of SiC

The gas phase during the chemical vapor deposition of silicon carbide from CH{sub 3}SiCl{sub 3} has been investigated by means of FTIR spectroscopy in the in situ conditions. Results show the formation of SiCl{sub 4} and CH{sub 4} molecules which are the transition products in the deposition process, according to earlier suppositions. The gas phase reaction induced by small amounts of HCl (or H{sub 2}O) in the system is an autocatalytic one. The mechanism of surface reactions is proposed. The importance of gas phase analysis in the deposition process is indicated.

Application of SRIXE and XANES to the determination of the oxidation state of iron in prostate tissue sections

Normal prostate and cancerous prostate tissue sections were analyzed using synchrotron radiation-induced X-ray emission and X-ray absorption near-edge structure (XANES) at the X-26A microprobe beam line located at the National Synchrotron Light Source, Brookhaven National Laboratory, USA. In both measurements, a monochromatic beam of size of 16×14 μm2 was applied. Two-dimensional scans of selected areas of non-cancerous and cancerous tissue sections were performed in order to obtain the distributions of various trace element concentrations. The XANES spectra were recorded for selected points containing high concentrations of iron. These measurements were performed with the aim of determining the oxidation state of iron. It was found that the iron concentration was much higher in the cancerous sections of the analyzed tissues than in the non-cancerous sections. From the results of XANES spectra analysis, iron in cancerous prostate tissue sections mostly occurs in the +3 oxidation state.

Trace element analysis by means of synchrotron radiation, XRF, and PIXE: selection of sample preparation procedure

Abstract When it comes to biological samples, trace element (TE) determination has to cope with very low concentrations, sometimes even below the minimum detectable limit (MDL). This is why special sample preparation procedures have to be employed so that the TE concentration in the specimen is effectively enhanced in a known way. The aim of this study was the selection of a proper sample preparation procedure by determination of selected element concentrations in different types of biological samples. In this work several sample preparation procedures were applied in order to choose the best one for specific experimental needs. The methods included: (a) tissue sectioning method (if appropriate); (b) dry method without chemical treatment — the samples were dried, homogenized and pressed into pellet; (c) wet method with chemical treatment — the samples were mineralized. The analyses were performed with different analytical methods in order to confirm the results obtained and in order to determine the influence of target preparation procedure on the level of elemental concentrations determination. The measurements were done by means of SRIXE (synchrotron radiation induced X-ray emission), EDXRF (energy dispersive X-ray fluorescence), TR-XRF (total reflection X-ray fluorescence), and PIXE (proton-induced X-ray emission). The above methods are described and the analytical results discussed. The results of the elemental analyses performed with different techniques show a good agreement only for some elements. The mineralization process increases the sensitivity of elemental determination only for selected elements. In other cases one could observe decreasing of elemental concentration in respect to non mineralized samples. Selection of sample preparation procedure depends on analytical requirements.

Analysis of renal stones by FTIR spectroscopy

A study of the chemical composition of renal stones is important for understanding their etiology. And the therapy for the stone disease is usually based on the analysis of calculi, permitting a porper management of the disease and the prevention of its recurrence. FTIR spectroscopy has been used for urinary stones analysis. The routine, easy and rapid measurements give unambiguous information about the stone composition. Especially a precise wavelength scale of the Fourier method is helpful here. A relatively good spatial resolution is important as very often the stones are composed of core and various layers of different chemical composition. A quantitative determination of the proportion of various materials in calculi is also possible.