The Influence of NH4NO3 and NH4ClO4 on Porous Structure Development of Activated Carbons Produced from Furfuryl Alcohol

The influence of NH4NO3 and NH4ClO4 on the porous texture and structure development of activated carbons produced from a non-porous polymeric precursor synthesized from furfuryl alcohol has been studied. The non-doped counterparts were prepared and studied for comparison purposes. NH4NO3 and NH4ClO4-doped polymers were carbonized under N2 atmosphere at 600 °C, followed by CO2 activation at 1000 °C and the obtained carbon materials and activated carbons were thoroughly characterized. The porosity characterization data have shown that NH4NO3-derived ACs present the highest specific surface area (up to 1523 m2/g in the experimental conditions studied), and the resulting porosity distributions are strongly dependent on the activation conditions. Thus, 1 h activation is optimum for the microporosity development, whereas larger activation times lead to micropores enlargement and conversion into mesopores. The type of doping salts used also has a substantial impact on the surface chemical composition, i.e., C=O groups. Moreover, NH4NO3 and NH4ClO4 constitute good sources of nitrogen. The type and contribution of nitrogen species are dependent on the preparation conditions. Quaternary nitrogen only appears in doped samples prepared by carbonization and pyrrolic, pyrydinic, and nitrogen oxide groups appear in the NH4NO3 -series. NH4NO3 incorporation has led to optimized materials towards CO2 and C2H4 sorption with just 1 h activation time.This research was funded by Rector of the West Pomeranian University of Technology in Szczecin for Ph.D. students of the Doctoral School, grant number ZUT/23/2022

Diagnosis of myelodysplastic syndromes in Poland: Polish Adult Leukemia Group (PALG) 2021 recommendations

Myelodysplastic syndromes (MDS) are a heterogeneous group of neoplastic diseases of the hematopoietic cells manifested by ineffective hematopoiesis and a tendency to transform into acute myeloid leukemia. MDS should be considered in the differential diagnosis of cytopenia, especially in the elderly. This article presents the recommendations of MDS experts of the Polish Adult Leukemia Group (PALG) for the diagnosis of myelodysplastic syndromes. We present current classifications and prognostic indices, as well as diagnostic examinations recommended for MDS: cytological, histopathological, immunophenotypic, cytogenetic and molecular tests. The aim of the study is to implement up-to-date knowledge about myelodysplastic syndromes into routine clinical practice, from the diagnosis of cytopenia to the specific diagnosis and prognosis in MDS patients.  Myelodysplastic syndromes (MDS) are a heterogeneous group of neoplastic diseases of the hematopoietic cells manifested by ineffective hematopoiesis and a tendency to transform into acute myeloid leukemia. MDS should be considered in the differential diagnosis of cytopenia, especially in the elderly. This article presents the recommendations of MDS experts of the Polish Adult Leukemia Group (PALG) for the diagnosis of myelodysplastic syndromes. We present current classifications and prognostic indices, as well as diagnostic examinations recommended for MDS: cytological, histopathological, immunophenotypic, cytogenetic and molecular tests. The aim of the study is to implement up-to-date knowledge about myelodysplastic syndromes into routine clinical practice, from the diagnosis of cytopenia to the specific diagnosis and prognosis in MDS patients.

The 42nd Symposium Chromatographic Methods of Investigating Organic Compounds : Book of abstracts

The 42nd Symposium Chromatographic Methods of Investigating Organic Compounds : Book of abstracts. June 4-7, 2019, Szczyrk, Polan

Application of TiO₂ Supported on Nickel Foam for Limitation of NO_x in the Air via Photocatalytic Processes

TiO2 was loaded on the porous nickel foam from the suspended ethanol solution and used for the photocatalytic removal of NOx. Such prepared material was heat-treated at various temperatures (400–600 °C) to increase the adhesion of TiO2 with the support. Obtained TiO2/nickel foam samples were characterized by XRD, UV–Vis/DR, FTIR, XPS, AFM, SEM, and nitrogen adsorption at 77 K. Photocatalytic tests of NO abatement were performed in the rectangular shape quartz reactor, irradiated from the top by UV LED light with an intensity of 10 W/m2. For these studies, a laminar flow of NO in the air (1 ppm) was applied under a relative humidity of 50% and a temperature of 28 °C. Concentrations of both NO and NO2 were monitored by a chemiluminescence NO analyzer. The adsorption of nitrogen species on the TiO2 surface was determined by FTIR spectroscopy. Performed studies revealed that increased temperature of heat treatment improves adhesion of TiO2 to the nickel foam substrate, decreases surface porosity, and causes removal of hydroxyl and alcohol groups from the titania surface. The less hydroxylated surface of TiO2 is more vulnerable to the adsorption of NO2 species, whereas the presence of OH groups on TiO2 enhances the adsorption of nitrate ions. Adsorbed nitrate species upon UV irradiation and moisture undergo photolysis to NO2. As a consequence, NO2 is released into the atmosphere, and the efficiency of NOx removal is decreasing. Photocatalytic conversion of NO to NO2 was higher for the sample heated at 400 °C than for that at 600 °C, although coverage of nickel foam by TiO2 was lower for the former one. It is stated that the presence of titania defects (Ti3+) at low temperatures of its heating enhances the adsorption of hydroxyl groups and the formation of hydroxyl radicals, which take part in NO oxidation. Contrary to that, the presence of titania defects in TiO2 through the formation of ilmenite structure (NiTiO3) in TiO2/nickel foam heated at 600 °C inhibits its photocatalytic activity. No less, the sample obtained at 600 °C indicated the highest abatement of NOx due to the high and stable adsorption of NO2 species on its surface

Fabrication of Antibacterial Metal Surfaces Using Magnetron-Sputtering Method

One-hundred-nanometer films consisting of silver, copper, and gold nanocrystallites were prepared, and their antibacterial properties were quantitatively measured. The magnetron-sputtering method was used for the preparation of the metallic films over the glass plate. Single- and double-layer films were manufactured. The films were thoroughly characterized with the XRD, SEM, EDS, and XPS methods. The antibacterial activity of the samples was investigated. Gram-negative Escherichia coli, strain K12 ATCC 25922 (E. coli), and Gram-positive Staphylococcus epidermidis, ATCC 49461 (S. epidermidis), were used in the microbial tests. The crystallite size was about 30 nm in the cases of silver and gold and a few nanometers in the case of copper. Significant oxidation of the copper films was proven. The antibacterial efficacy of the tested samples followed the order: Ag/Cu > Au/Cu > Cu. It was concluded that such metallic surfaces may be applied as contact-killing materials for a more effective fight against bacteria and viruses

The Influence of NH₄NO₃ and NH₄ClO₄ on Porous Structure Development of Activated Carbons Produced from Furfuryl Alcohol

The influence of NH4NO3 and NH4ClO4 on the porous texture and structure development of activated carbons produced from a non-porous polymeric precursor synthesized from furfuryl alcohol has been studied. The non-doped counterparts were prepared and studied for comparison purposes. NH4NO3 and NH4ClO4-doped polymers were carbonized under N2 atmosphere at 600 °C, followed by CO2 activation at 1000 °C and the obtained carbon materials and activated carbons were thoroughly characterized. The porosity characterization data have shown that NH4NO3-derived ACs present the highest specific surface area (up to 1523 m2/g in the experimental conditions studied), and the resulting porosity distributions are strongly dependent on the activation conditions. Thus, 1 h activation is optimum for the microporosity development, whereas larger activation times lead to micropores enlargement and conversion into mesopores. The type of doping salts used also has a substantial impact on the surface chemical composition, i.e., C=O groups. Moreover, NH4NO3 and NH4ClO4 constitute good sources of nitrogen. The type and contribution of nitrogen species are dependent on the preparation conditions. Quaternary nitrogen only appears in doped samples prepared by carbonization and pyrrolic, pyrydinic, and nitrogen oxide groups appear in the NH4NO3 -series. NH4NO3 incorporation has led to optimized materials towards CO2 and C2H4 sorption with just 1 h activation time

FeCl3-Modified Carbonaceous Catalysts from Orange Peel for Solvent-Free Alpha-Pinene Oxidation

The work presents the synthesis of FeCl3-modified carbonaceous catalysts obtained from waste orange peel and their application in the oxidation of alpha-pinene in solvent-free reaction conditions. The use of waste orange peel as presented here (not described in the literature) is an effective and cheap way of managing this valuable and renewable biomass. FeCl3-modified carbonaceous materials were obtained by a two-stage method: in the first stage, activated carbon was obtained, and in the second stage, it was modified by FeCl3 in the presence of H3PO4 (three different molar ratios of these two compounds were used in the studies). The obtained FeCl3-modified carbon materials were subjected to detailed instrumental studies using the methods FT-IR (Fourier-transform Infrared Spectroscopy), XRD (X-ray Diffraction), SEM (Scanning Electron Microscope), EDXRF (Energy Dispersive X-ray Fluorescence) and XPS (X-ray Photoelectron Spectroscopy), while the textural properties of these materials were also studied, such as the specific surface area and total pore volume. Catalytic tests with the three modified activated carbons showed that the catalyst obtained with the participation of 6 M of FeCl3 and 3 M aqueous solutions of H3PO4 was the most active in the oxidation of alpha-pinene. Further tests (influence of temperature, amount of catalyst, and reaction time) with this catalyst made it possible to determine the most favorable conditions for conducting oxidation on this type of catalyst, and allowed study of the kinetics of this process. The most favorable conditions for the process were: temperature of 100 °C, catalyst content of 0.5 wt% and reaction time 120 min (very mild process conditions). The conversion of the organic raw material obtained under these conditions was 40 mol%, and the selectivity of the transformation to alpha-pinene oxide reached the value of 35 mol%. In addition to the epoxy compound, other valuable products, such as verbenone and verbenol, were formed while carrying out the process

Activated Carbons Obtained from Orange Peels, Coffee Grounds, and Sunflower Husks—Comparison of Physicochemical Properties and Activity in the Alpha-Pinene Isomerization Process

This work presents studies on the preparation of porous carbon materials from waste biomass in the form of orange peels, coffee grounds, and sunflower seed husks. The preparation of activated carbons from these three waste materials involved activation with KOH followed by carbonization at 800 °C in an N2 atmosphere. This way of obtaining the activated carbons is very simple and requires the application of only two reactants. Thus, this method is cheap, and it does not generate much chemical waste. The obtained activated carbons were characterized by XRD, SEM, XPS, and XRF methods. Moreover, the textural properties, acidity, and catalytic activity of these materials were descried. During catalytic tests carried out in the alpha-pinene isomerization process (the use of the activated carbons thus obtained in the process of alpha-pinene isomerization has not been described so far), the most active were activated carbons obtained from coffee grounds and orange peels. Generally, the catalytic activity of the obtained materials depended on the pore size, and the most active activated carbons had more pores with sizes of 0.7–1.0 and 1.1–1.4 nm. Moreover, the presence of potassium and chlorine ions in the pores may also be of key importance for the alpha-pinene isomerization process. On the other hand, the acidity of the surface of the tested active carbons did not affect their catalytic activity. The most favorable conditions for carrying out the alpha-pinene isomerization process were the same for the three tested activated carbons: temperature 160 °C, amount of the catalyst 5 wt.%, and reaction time 3 h. Kinetic studies were also carried out for the three tested catalysts. These studies showed that the isomerization over activated carbons from orange peels, coffee grounds, and sunflower seed husks is a first-order reaction

Activated Carbon Modification towards Efficient Catalyst for High Value-Added Products Synthesis from Alpha-Pinene

DT0-activated carbons modified with HCl and HNO3 acids, which were used for the first time in the catalytic process of alpha-pinene isomerization, are presented in this study. The carbon materials DT0, DT0_HCl, DT0_HNO3, and DT0_HCl_HNO3 were examined with the following methods: XRF, SEM, EDX, XPS, FT-IR, XRD, and N2 adsorption at −196 °C. It was shown that DT0_HCl_HNO3-activated carbon was the most active material in the alpha-pinene isomerization process. Detailed studies of alpha-pinene isomerization were carried out over this carbon by changing the reaction parameters such as time (5–180 min) and temperature (60–175 °C). The 100% conversion of alpha-pinene was achieved at the temperature of 160 °C and catalyst content of 5 wt% after 3 h over the DT0_HCl_HNO3 catalyst. Camphene and limonene were the main products of the alpha-pinene isomerization reaction

Thermal treatment and properties of Ni-SDC cathode for high temperature fuel cells

The composite Ni-SDC cathode is a key element in the formulation of the hybrid MCFC/SOFC system. It must encompass electrical and ionic conductivity, high catalytic activity to allow for the reduction of oxygen and the oxidation of carbon dioxide and provide high permeability for gaseous reactants. This requires not only a specific chemical composition but also the microstructure has to be designed and specifically manufactured.These studies present the thermal treatment process and resultant properties of Ni-SDC cathodes with various SDC volume fractions. A new procedure for producing the Ni-SDC cathode was optimized based on the reference sintering process for pure Ni, modifying the temperature profile as well as the atmospheric gas composition (air, nitrogen, nitrogen + hydrogen mixture) and the sintering temperature (800°C, 900°C, 1000°C). This was done using thermogravimetric analysis (TGA) and electron microscopy (SEM).The research results show that the addition of SDC, with a specific atmospheric formulation, facilitates the organic phase decomposition. It has been observed that an increase in sintering temperature enhances mechanical strength and improves electrical conductivity