For the analysis of slurry dispersions, a method combining electrical measurements—which imply internal structure through electronic or ionic conductivity—with rheological measurements, known as the rheo-impedance method, has been developed. Most previous studies of the electronic or ionic conductivity of slurries have used AC-based approaches; the use of DC-based methods remains extremely limited. In this study, we used an anode model slurry containing graphite particles for lithium-ion batteries to compare DC and AC responses under shear and to elucidate the electronic conduction mechanisms involved. With the DC method, changes in the state of dispersion of the slurry immediately after a step change in shear rate could be captured at 0.1-second intervals. By contrast, the AC method enabled the total resistance to be separated into components originating from graphite (solid phase) and dispersion medium (liquid phase). In addition, analysis of the graphite-derived current response in the DC method revealed that the current is governed by the applied shear stress, irrespective of solids content. On the basis of previous experimental and discrete element method simulation results showing that shear stress is correlated with particle connectivity, electrons were inferred to be conducted through network structures formed by contacts between graphite particles.

The molecular mechanism by which emulsifiers inhibit starch retrogradation has not been fully understood. The retardation effect of emulsifiers on potato starch retrogradation was investigated using dynamic viscoelastic measurements and differential scanning calorimetry. Molecular-level investigations of the adsorption between starch and amylose with sucrose fatty acid esters were conducted using isothermal titration calorimetry to elucidate the mechanism by which emulsifiers attenuate starch retrogradation. Starch gels containing highly hydrophilic and poorly hydrophilic emulsifiers exhibited a small increase in storage elastic modulus at 4 °C. Amylose chains exist in water with their helices loosened, and the hydrophilic groups of sucrose fatty acid ester molecules adsorb onto the amylose chains via hydrogen bonding and van der Waals interactions. The adsorbed emulsifiers acted as steric hindrance and inhibited amylose chain reaggregation, thus suppressing retrogradation. Through a multi-scale investigation—using rheology, thermal analysis, and calorimetry—this study effectively elucidates the molecular-level inhibitory effects of emulsifiers on starch retrogradation.

This article reviews papers and review articles published in Volume 53 of Nihon Reoroji Gakkaishi in 2025. The volume covered a broad range of rheological studies, including polymer liquids and solids, complex fluids, polyelectrolytes, gels, elastomers, nanocellulose suspensions, and bio-related soft materials. In particular, a special issue on “Rheology of Glasses” highlighted recent advances in glassy polymers, glass transition phenomena, and nonlinear mechanical responses. In addition to experimental studies, theoretical and computational approaches based on molecular simulations and information science were also featured, reflecting the diversification of rheological research methodologies. Educational articles for beginners and interdisciplinary readers were continuously published as well, demonstrating the role of the journal not only as a platform for research papers but also as a medium for education and knowledge sharing in rheology.