Irena Brunarska

Current wound care still lacks multifunctional dressings capable of providing both structural support and controlled therapeutic activity. Developing such materials requires polymer matrices with tunable physicochemical properties, achievable through the rational selection of components and modifiers. In this study, polymer composites based on poly(vinyl alcohol) (PVA) and carboxymethyl cellulose (CMC), modified with glycerol and montmorillonite (MMT), were synthesized using a novel and rapid preparation method aimed at producing structurally adjustable matrices. The obtained materials were characterized by FTIR, SEM, and AFM analyses. FTIR spectra confirmed the competitive role of glycerol in reducing cross-linking efficiency and the compensatory effect of MMT in enhancing molecular interactions and structural density. The interaction between the two modifiers resulted in hybrid structures with intermediate organization, neither purely crystalline nor amorphous. SEM imaging revealed that glycerol promotes porosity, while higher MMT content stabilizes the polymer matrix, enhancing surface homogeneity. AFM revealed that the average roughness (1 × 1 μm scans) increased from 0.98 μm (sample B7) to 5.30 μm (sample C7) after glycerol addition. In conclusion, obtained results demonstrate the synergistic and opposing roles of glycerol and MMT, ultimately enabling the design of multifunctional polymer composites and warranting further investigation through XRD, DSC, rheology, and swelling capacity analyses.

Microplastics (MPs) represent a persistent class of emerging contaminants, of which significant amounts can be found in sewage sludge. In this study, the effect of hydrothermal carbonization (HTC) temperature on MPs and the properties of digested sewage sludge (DSS) was evaluated. The HTC process was carried out at temperatures of 200, 210, and 220 °C for 2 h in a batch reactor, and the solid products were subjected to (i) mass balance and fuel properties and (ii) microplastic occurrence analysis using Confocal Raman Microspectroscopy and Scanning Electron Microscopy. In digested sludge, 2700 ± 475 MP particles/100 g d.m. were detected, mostly fragments with ~350 ± 100 fibers. Hydrocharcontained only black and brown fragments in the following amounts: 4175 ± 575 (200 °C), 4450 ± 700 (210 °C), and 1450 ± 590 (220 °C), respectively, after 2 h. The microplastic removal rate was 54% for the highest temperature. Polystyrene (PS) was identified in untreated sludge, while only PE was detected after HTC at 200–210 °C, and no MPs were identifiable at 220 °C. The surfaces of post-MPs exhibited progressive degradation with increasing HTC temperature. The results confirm that HTC lowers the content and alters the physicochemical properties of microplastics, reducing their thermal stability and degrading their structure, while simultaneously improving the fuel properties of hydrochars by increasing the calorific value and carbon content.

Badanie rudy niklu saprolitycznego przeprowadzone w rejonie Mandiodo w O kręgu Północnym Konawe w I ndonezji wykazało wysoką zawartość niklu. Analizy mineralogiczne i geochemiczne od podłoża skalnego do próbek horyzontu saprolitu ujawniają cechy rudy jako produktu wietrzenia z podłoża perydotytowego składającego się głównie z oliwinu, piroksenu i serpentynu. Wyniki ujawniają zaawansowany proces serpentynizacji, na który wskazuje dominacja oliwinu i serpentynu reprezentowanych odpowiednio przez forsteryt i chryzotyl, z mniejszą ilością enstatytu jako członka grupy piroksenów w podłożu skalnym. Ponadto obfitość grup mineralnych goethytu, amfibolu i chlorytu w saprocie i saprolicie wskazuje na początkowy etap wietrzenia. Po zwietrzeniu podłoża skalnego serpentynit jest głównym źródłem Ni w poziomie saproku i saprolitu, z niewielkim występowaniem w goethycie. Pentlandyt rzadko występuje w podłożu skalnym, ale pojawia się z bardzo wysoką zawartością Ni. W rudzie saprolitu zawartość Ni w minerałach grupy serpentynu i Fe w goethycie wzrosła drastycznie do odpowiednio 4,6 i 43,8% wag., po czym nastąpiło drastyczne wyczerpanie Si i Mg do odpowiednio 7,3 i 3,9% wag. Obecność chromitu w poziomie saprolitu odgrywa znaczącą rolę podczas wzbogacania Cr i Al, a Mn jest obecny zarówno w tlenkach Mn, jak i w goethycie. Zmiany geochemiczne w poziomie saprolitu wskazują na perspektywę przyszłych zasobów metali krytycznych w badanym obszarze.

In the presented work, titanosilicate with the MWW structure (Ti-MWW) was hydrothermally synthesized using boron and titanium precursors, with piperidine as a structure-directing agent. The resulting layered zeolite precursor, with a Si/Ti molar ratio of 50, was treated in an HNO₃ solution to remove extraframework Ti and B species. The acid-modified zeolite was functionalized with transition metal cations (Cu²⁺, Fe²⁺, Mn²⁺) and trinuclear oligocations (Fe(3) and Mn(3)). The application of this catalytic system is supported by the presence of titanium in the catalytic support structure—similar to a commercial system, V₂O₅–TiO₂. The obtained samples were characterized with respect to their structure (P-XRD, DRIFT), textural parameters (low-temperature N₂ sorption), surface acidity (NH₃-TPD), transition metal content (ICP-OES) and form (UV–vis DRS) as well as catalyst’s reducibility (H₂-TPR). Ti-MWW zeolite samples modified with transition metals were evaluated as catalysts for the selective catalytic reduction of NO with ammonia (NH₃-SCR). The effective temperature range for the NO conversion varied depending on the type of active phase used to functionalize the porous support. The catalytic performance was influenced by transition metal content, its form, and accessibility for reactants as well as interactions between the active phase and titanium-containing support. Among the catalysts tested, the copper-modified Ti-MWW zeolite showed the most promising results, maintaining 90% NO conversion rates across a relatively broad temperature range from 200 to 325 °C. This catalyst meets the requirements of modern NH₃-SCR installations, which aim to operate in the low-temperature region, below 250 °C.

This report presents the results of a petrographical and mineralogical (optical microscopy, BSE-EDS image analysis) study of zircon in samples from the Lower Nubian monzogranite. The mineral occurs as smaller grains (< 80 μm) in a fine-grained quartz-feldspar-matrix, coexisting with other accessory minerals including biotite, clinochlore, titanite, and britholite-(Ce). Zircon is also present within biotite and britholite-(Ce), suggesting that it started crystallization at about the same time as these two minerals. Two types of thorite inclusions within zircon are reported in this study. Type 1 is widely distributed throughout the zircon grain, forming crystallites of which each is typically < 1 μm in size. Type 2 is relatively larger (5-15 μm) and occurs only in one part of the grain. For the thorite inclusions, three possible origins are briefly discussed: (1) exsolution of thorite from zircon; (2) dissolution/reprecipitation of zircon; and (3) growth syngenetically with zircon. Of these potential hypotheses, the syngenetic growth model seems more favorable for zircon-thorite intergrowths than the other two hypotheses. Thorite inclusions and their host zircons seem to have grown from magma rather than hydrothermal or supercritical solutions. Here, they have primary textures and consistent chemical compositions that are consistent with whole-rock geochemistry.