The use of advanced oxidation processes (AOPs) for micropollutant removal in wastewater is challenging, given the scavenging effects of dissolved organic matter (DOM). Chlorine photolysis (UV/Cl) offers unique advantages over conventional AOPs, with wavelength- and pH-dependent generation of reactive species, while being largely compatible with existing disinfection dosing infrastructure. Here, the UV/Cl treatment of carbamazepine (CBZ) was optimized as a test case by varying UV wavelength and solution pH in the presence of humic acid and various types of wastewater DOM isolates (colloidal, hydrophobic, and transphilic). CBZ degradation rates, competitive quenching experiments, and electron paramagnetic resonance spectroscopy revealed important wavelength- and pH-dependent trade-offs in the dominant oxidants. At pH 3, CBZ degradation was hindered by DOM due to scavenging of nonselective radicals. At pH 8, ozone formation minimized DOM interference and improved CBZ removal. Shifting to longer wavelengths caused changes parallel to raising the pH. Three-dimensional excitation-emission matrix fluorescence analysis revealed preferential reactivity with fulvic- and humic-like fluorophores during treatment. Microtoxicity bioassays indicated a slight increase in acute toxicity after UV/Cl exposure, and LC-MS identified hydroxylated, epoxidized, and chlorinated transformation products. Results highlight the potential for strategic optimization of UV/Cl to mitigate DOM interference in water treatment.
Most organoids are cultured in Matrigel, a complex and poorly defined matrix that limits our mechanistic understanding. Synthetic hydrogels offer a versatile alternative, providing precise control over mechanical and biochemical cues. Using two topologically different types of hydrogel precursors, branched poly(ethylene glycol) (PEG) and PEG bisdendrons, we have obtained a library of hydrogels via thiol-ene cross-linking with branched PEG-thiol. Their chemical conversion was monitored by Raman spectroscopy, while swelling and mechanical properties, including elastic, viscoelastic, and relaxation parameters, were systematically evaluated. Bisdendron hydrogels dissipate stress through abundant weak interactions, conferring adaptive viscoelastic behavior, an underexplored feature in a 3D culture. To link macromolecular dynamics with bulk properties, polymer chain mobility and internal architecture were probed using MAS solid-state NMR and freeze-fracture cryo-SEM. To introduce bioactivity, RGD peptides were used and immobilized via thiol-ene chemistry, forming spatially organized clusters within the hydrogels. This strategy enables the design of customizable matrices with tunable mechanics, adjustable porosity, and controlled bioactive presentation, closely mimicking native microenvironments. Our platform can provide a chemically defined and versatile toolbox for organoid culturing.
This study employs a novel integration of Computer Vision (CV) and Deep Learning (DL) algorithms (CNN/RNNLSTM algorithm) to investigate the acidity and photocatalytic performance of a green nanocatalyst: copper oxide nanoparticles supported on sodalite nanozeolite (nSOD@CuO-NPs). The nanocatalyst, synthesized using Camelia sinensis (green tea) extract, was characterized, revealing the sodalite, tenorite, and cuprite phases and a good compromise between surface area and stability. The NH3-TPD analysis indicated a presence of weak-to-moderate acidity of the nanocatalysts and a significant reduction in the density of acid sites upon CuO-NPs loading, decreasing from Ns = 135 & micro;mol NH3 g-1 catalyst (nSOD) to Ns = 58 & micro;mol NH3 g-1 catalyst (nSOD@CuO-NPs), probably due to occupation/blockage of nanozeolite active sites by the nanoparticles. This modification suggests a plausible transition from Br & Oslash;nsted-dominant to Lewis-dominant acidity, potentially enhancing oxidation reactions. Exploratory Data Analysis (EDA) of heterogeneous photocatalysis assays demonstrated that nSOD@CuONPs achieved 82% removal of a highly concentrated (70 L-1) binary mixture of Crystal Violet (CV) and Methylene Blue (MB) dyes after 240 min at an optimal concentration of 0.8 L-1 and neutral pH. The DL/CV model generated a 3D morphology with an acidity heat map, enabling the proposal of a comprehensive photocatalytic degradation mechanism under visible light, highlighting the critical role of Cu-based Lewis acid sites and the generated ROS in the degradation pathway. A subsequent kinetic study on the main byproduct, aniline, showed an 89.6% removal, confirming the promising photocatalytic activity of the nSOD@CuO-NPs for complete wastewater treatment.
Flexible magnetoelectronics face a major challenge in maintaining functionality under mechanical strain. This research investigates how biaxial multicracking affects the magnetic properties of nanometric thin films, specifically by separating magnetoelastic from magnetostatic effects. Using a unique experimental platform, we show that in magnetostrictive Co films, the magnetic behavior is dominated by stress-induced magnetoelastic effects. In contrast, in non-magnetostrictive films, the magnetic changes only appear once multicracking begins, allowing us to demonstrate the magnetostatic contributions from fragmentation. Our findings reveal that the variation in the saturation field correlates directly with fragment shape. This work demonstrates that fragmentation is not just a failure mechanism but a controllable process whose magnetic effects can be understood and leveraged for designing next-generation flexible devices.
Low-loaded 0.3 wt.% Pt/SiO2 & horbar;Al2O3 catalysts, either unmodified or modified with WO3 or Fe2O3, were investigated to elucidate the reaction pathways and mechanistic features of the NOX selective catalytic reduction by hydrogen (H-2-SCR) over a wide temperature range. At low temperatures (50-100 degrees C), catalytic activity is governed by H-2 activation, which is significantly enhanced by WO3 addition, whereas Fe2O3 inhibits NO reduction and consequently suppresses low-temperature N2O formation. In the intermediate temperature range (80-200 degrees C), distinct H-2-SCR behaviors are linked to the reactivity of in situ-formed NH3 toward residual NOX. This NH3-SCR type pathway is strongly promoted by WO3, while Fe2O3 hampers NH3 activation at low temperature, leading to increased NH3 slip. However, this reaction pathway remains limited to a narrow temperature window, as it requires the presence of unconverted NOX. At higher temperatures (> 150 degrees C), the NH3 + O-2 reaction, previously identified as the dominant deNO(X) route, is largely unaffected by the addition of WO3 or Fe2O3. Moreover, the undesired N2O formation in this high temperature range originates not only from the ammonia oxidation route, but a possible contribution from the decomposition of ammonium nitrate-like surface species was also evidenced.
