The cross-linking temperature of polymers may affect the surface characteristics and molecular arrangement, which are responsible for their mechanical and physico-chemical properties. The aim of this research was to determine and explain in detail the mechanism of unit interlinkage of two-component chitosan/1,3-β-d-glucan matrices gelled at 90 °C. This required identifying functional groups interacting with each other and assessing surface topography providing material chemical composition. For this purpose, various spectroscopic and microscopic approaches, such as attenuated total reflection Fourier transform infrared spectroscopy (ATR FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM), were applied. The results indicate the involvement mainly of the C-C and C-H groups and C=O⋯HN moieties in the process of biomaterial polymerization. Strong chemical interactions and ionocovalent bonds between the N-glucosamine moieties of chitosan and 1,3-β-d-glucan units were demonstrated, which was also reflected in the uniform surface of the sample without segregation. These unique properties, hybrid character and proper cell response may imply the potential application of studied biomaterial as biocompatible scaffolds used in regenerative medicine, especially in bone restoration and/or wound healing.

CO₂ methanation is a very promising technology for the production of alternative fuels with the simultaneous use of greenhouse gases. Therefore, intensive research is carried out on the optimization of catalysts with excellent properties for operation in the area of low temperatures. Here, we present research on a catalyst composed of 19 wt % NiO supported on alumina/calcium aluminate. The catalyst was modified with V₂O₅ in order to be suited for extrusion and scale-up in the frame of power to gas technology. Samples with various vanadium contents (Ni–xV, where x represents the amount of vanadium) were prepared in the form of ground granules obtained from 0.5 mm diameter spherical grains. X-ray diffraction (XRD), transmission electron microscopy (TEM), skeletal infrared (IR), diffuse reflectance ultraviolet–visible-near-infrared (DR-UV–vis-NIR), and X-ray photoelectron (XPS) spectroscopies, as well as H₂ temperature-programmed reduction (H₂-TPR), were used to characterize the samples. Catalytic performances of the catalyst samples were tested in CO₂ hydrogenation at 1 atm. Among the many supported Ni catalysts tested in our laboratories, the catalysts of 0.5 and 1 wt % V showed very high activity, with the highest CH₄ yield of 97% at 623 K. These catalysts exhibited 100% CH₄ selectivity up to 673 K. The excellent performances of the studied catalysts are attributed to the possible formation of Ni–V solid solution alloy nanoparticles.