New binuclear complexes of La(III), Nd(III), Sm(III), Eu(III), Gd(III) and Tb(III) ions with mefenamic acid were obtained in solid phase. For all compounds considered, complexation occurs at pH 6–6.5. The analyzed complexes were characterized on the basis of chemical and elemental analyses, molar conductance, UV–Vis, IR and 1H NMR spectroscopies as well as thermoanalytical techniques. According to the research results, the molecular formula of the complexes is Ln₂(C₁₅H₁₄NO₂)₃(OH)₃×nH₂O, with the exception of the La(III) complex which has the formula La₂(C₁₅H₁₄NO₂)₅(OH). The results show that only the carboxyl group is involved in the coordination of the rare earth ions in the bidentate mode. Coordination does not occur through the nitrogen atom. All the complexes are soluble in DMSO, and they are nonelectrolytes. The TG-FTIR technique was employed in order to study a decomposition pathway of the obtained compounds. The received results provide information on the composition, thermal stability, thermal decomposition, as well as the gaseous products that evolved during the thermal decomposition of the considered compounds.

The main purpose of the research was to obtain and study hybrid materials based on three different nano-oxides commonly used in the cosmetic and pharmaceutical industries: Al₂O₃, TiO₂, and ZnO, with the natural bioactive polysaccharide fucoidan. Since the mentioned oxides are largely utilized by industry, there is no doubt that the presented studies are important from an environmental point of view. On the basis of the textural studies (dynamic light scattering DLS, low temperature nitrogen adsorption, X-ray diffraction analysis XRD, scanning electron microscopy SEM) it was proved that the properties of the hybrid materials differ from the pure components of the system. Moreover, the advanced thermal analysis (TG-DTG-DSC) combined with the evolved gas analysis using Fourier transformed infrared spectroscopy (FTIR) and mass spectrometry were applied to describe the thermal decomposition of fucoidan, oxides and hybrid materials. It was found that the interactions between the polymer and the oxides results in the formation of the hybrid materials due to the functionalization of the nanoparticles surface, and that their thermal stability increased when compared to the pure substrates. Such findings definitely fill the literature void regarding the fucoidan based hybrid materials and help the industrial formulators in the preparation of new products.