Nanocelluloses are the subject of much interest on the account of their mechanical properties, high surface area, porosity, etc. Typically, sulfuric acid is used to produce cellulose nanocrystals with high aspect ratio and dispersibility in water suspensions. However, hydrolysis in sulfuric acid leads to cellulose esterification, which has some drawbacks such as lower thermal stability of nanocellulose. Hydrochloric acid does not cause functionalization of the nanocellulose surface, yet yields in poor colloidal stability in aqueous solutions due to the lack of ionic interactions between CNC/CNF and water molecules. Therefore, it should be possible to tune the colloidal stability of nanocellulose aqueous suspensions by modifying the properties of the solution (such as pH and/or the presence of surfactants). In this work, we attempted to obtain stable aqueous CNF suspensions via hydrochloric acid hydrolysis. Hydrolysis was performed at three time intervals, at 60 °C temperature and 6 mol/dm³ of hydrochloric acid. To find the optimum stabilizing conditions, the effect of different pH values and various surfactants on CNF stability was explored. The best stabilizing effect was observed at pH range 5-9 and in nonionic surfactant. The obtained products were characterized by using spectroscopic (FTIR), microscopic (AFM), thermogravimetric and X-ray diffraction techniques.

In this work, platinum nanoparticles (PtNPs) were synthesized by a modified polyol process using TEMPO-oxidized nanocellulose (TOCN) as a stabilizing and co-reducing agent. Different ratios of TOCN nanocellulose to Pt⁴⁺ ions were studied to establish the optimum stabilizing effect of PtNPs. The effect of different pH of aqueous TOCN suspensions on the morphology of PtNPs was also examined. It was proved that PtNPs can be obtained solely in the presence of TOCN without the use of an additional reducing agent or ethylene glycol. The morphology and structural properties of the nanocellulose‑platinum nanoparticles composites were assessed using spectroscopic, microscopic and diffraction techniques, The catalytic performance in 4-nitrophenol reduction was evaluated. Significant differences in reaction rate constants k were found depending on the pH of the TOCN suspension applied during Pt⁴⁺ reduction. The crucial effect of reaction conditions on PtNPs performance was confirmed in tests of antibacterial efficacy against E. coli.

The endophytic Basidiomycete Sporobolomyces ruberrimus protects its host Arabidopsis arenosa against metal toxicity. Plants inoculated with the fungus yielded more biomass and exhibited significantly fewer stress symptoms in medium mimicking mine dump conditions (medium supplemented with excess of Fe, Zn and Cd). Aside from fine-tuning plant metal homeostasis, the fungus was capable of precipitating Fe in the medium, most likely limiting host exposure to metal toxicity. The precipitated residue was identified by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-Ray Diffraction (XRD) and electron microscopy (SEM/TEM) with energy dispersive X-Ray analysis (EDX/SAED) techniques. The performed analyses revealed that the fungus transforms iron into amorphous (oxy)hydroxides and phosphates and immobilizes them in the form of a precipitate changing Fe behaviour in the MSR medium. Moreover, the complexation of free Fe ions by fungi could be obtained by biomolecules such as lipids, proteins, or biosynthesized redox-active molecules.

This study investigates the degradation mechanism of silk fibroin through Fourier-transformed infrared spectroscopy (FTIR) analysis. The secondary structure of silk fibroin-based materials is monitored using FTIR, and various estimators are calculated to assess the impact of degradation conditions and aging time. The oxidation estimator shows consistent growth, indicating peptide bond oxidation from the early stages of artificial aging, regardless of the conditions. The environment influences the hydrolysis estimator, with water introduction leading to significant changes. The crystallinity estimator reflects the overall degradation level, affected by oxidation and hydrolysis. XRD and FTIR analysis of historical silk banners up to 500 years old demonstrate a decrease in crystallinity and an increase in hydrolysis and oxidation. The presence of water accelerates the oxidation process, while crystallinity changes are primarily driven by oxidation. Fibroin degradation affects both antiparallel and parallel regions, with water playing a crucial role in accelerating hydrolysis and causing structural shifts. This study enhances our understanding of silk fibroin degradation and provides valuable insights for preserving historical silk artifacts.

Methane combustion over palladium-based catalysts is a critical process for reducing greenhouse gas emissions from lean-burn engines and natural gas installations, yet the role of oxide support in controlling both the population and the intrinsic reactivity of Pd active centres remains incompletely understood. In this work, Pd catalysts at two series of higher and lower loading were prepared on five oxide supports—Al₂O₃, CeO₂, SiO₂, TiO₂, and ZrO₂—and characterised by a complementary suite of techniques including SEM-EDX, XRD, BET, AAS, in situ CO-FTIR, DRIFTS with methanol as a probe molecule, and Raman spectroscopy. Catalytic activity testing revealed the order Pd/CeO₂ > Pd/ZrO₂ > Pd/Al₂O₃ > Pd/TiO₂ > Pd/SiO₂. In situ CO-FTIR site quantification showed that active site density spans nearly an order of magnitude across the series, with Pd/CeO₂ reaching 105.44 µmol g⁻¹ and Pd/Al₂O₃ only 11.63 µmol g⁻¹. Turnover frequency analysis revealed a striking inversion: Pd/Al₂O₃ exhibited the highest TOF (0.1327 s⁻¹), approximately six times greater than Pd/CeO₂ (0.0226 s⁻¹). DRIFTS/methanol profiling demonstrated that CeO₂ and ZrO₂ expose cooperative redox and basic centres that promote methane activation, while SiO₂ supports only weakly bound methoxy species, consistent with its lowest activity. These results establish that the oxide support simultaneously governs Pd dispersion—and hence site density—and the electronic environment of each Pd centre, thereby modulating intrinsic reactivity. High specific surface area alone does not guarantee catalytic performance, and rational support selection is therefore the decisive lever for optimising methane combustion catalysts at ultra-low Pd loadings. In all, our findings provide a quantitative, molecular-level framework that disentangles support-controlled site density from intrinsic site reactivity under identical reaction conditions. By combining in situ CO-FTIR, DRIFTS, and Raman spectroscopy with kinetic analysis on well-defined, high-purity oxide supports, this work transforms previously qualitative “support effects” in Pd-catalysed methane combustion into predictive structure–activity relationships.