Reduced-molar-mass low-acyl gellan gum was obtained by the centrifugation of an aqueous solution of commercially available food-grade gellan gum. The derived sample was characterized by NMR, FTIR, ICPE, and viscometry methods. The characteristics were compared with commercially available gellan gum Gelzan™. The main focus of the investigation is on the rheological properties of low-molar-mass-gellan ion-induced gels and the influence of reduced molar mass on gelling of gellan. The gels were prepared by adding 0.2–0.3 M of NaCl or KCl to the 0.6 g/dL gellan gum aqueous solution in a 1:1 ratio. The kinetics of gelling at room temperature, studied by rheological methods, strongly depends on molar mass and is practically independent of the temperature (up to 37 °C) and the type of ions. Analysis of the mechanical spectra characterized the obtained gels as weak gels. The gelling temperature achieved upon cooling for low-molar-mass gellan with a 0.1 M NaCl concentration was 39.0 °C (rheology) and 43.5–42.5 °C (visual observation). In summary, this study complements the existing knowledge about how the reduced molar mass of low-acyl gellan gum influences its rheological properties and gelling behavior in ion-induced systems and provides insights into the formulation of gellan-based gels, which can be effectively utilized in various food and pharmaceutical applications.

Ionic liquids (ILs) have a wide variety of applications in modern electrochemistry due to their unique electrolytic properties. In particular, they are promising candidates as dopants for polymeric membranes in potentiometric sensors and liquid-junction free reference electrodes. However, the effective use of ILs requires a comprehensive understanding of their electrolytic behavior in the polymeric phase. We report here the exploration of the electrolytic and diffusion properties of IL 1-hexyl-3-methyl-1H-imidazol-3-ium bis[(trifluoromethyl)sulfonyl]amide ([C₆Meim][NTf₂]) in a poly(vinyl chloride) matrix. Chronopotentiometry is utilized to determine the concentration of charge carriers, ionic diffusion coefficients and apparent dissociation constant of [C₆Meim][NTf₂] in PVC membranes plasticized with a mixture of [C₆Meim][NTf₂] and bis(2-ethylhexyl) sebacate (DOS) over a wide range of IL concentrations. The diffusion properties of [C₆Meim][NTf₂] are confirmed by NMR-diffusometry. The non-monotonic electrolytic behavior of the IL in PVC-DOS matrix is described for the first time. A maximum ionization degree and diffusion coefficient is observed at 30 wt.% of IL in the plasticizing mixture. Thus, it is shown that by varying the flexible parameter of the IL to plasticizer ratio in the polymeric phase one can tune the electrolytic and transport properties of sensing PVC membranes.