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Advances in the application of polymers for electrochemical cells require an understanding of their viscous deformation mechanisms and their interaction with moisture. Nanoindentation offers a localized, microscale testing alternative to traditional tensile testing. However, the viscoelastic nature of the polymers, combined with their increased compliance, presents challenges in the analysis of nanoindentation results. In addition, the dependence on moisture results in significant scatter and low repeatability. This study combines nanoindentation and tensile testing as a verification method and compares different correction protocols for static nanoindentation to investigate the mechanical behavior of polymer electrolyte membranes. Comparisons of different indentation devices, analysis methods, and indentation protocols show a significant overestimation of Young's modulus using the classical Oliver–Pharr method compared to values determined from tensile tests. Nanoindentation at different humidity levels revealed different mechanisms leading to a decrease in Young's modulus and hardness with increasing humidity. [ABSTRACT FROM AUTHOR]

The possibility for valorization of the waste lavender residue from the essential oil industry via solvent extraction was studied. The plant residue of Lavandula angustifolia, from which the lavender oil is extracted through steam distillation, contains Key Biologically Active Components (KBAC) such as: rosmarinic acid, caffeic acid, luteolin. The feasibility of the solvent extraction for their isolation was assessed by comparison of the kinetics and equilibrium of extraction of KBAC from spent and raw plant material (collected from the same batch before the steam distillation) using different solvent compositions. The parameters of the extraction process were experimentally and numerically optimized. To determine the most efficient solvent, two pure and two mixed solvents were tested: pure water, 99.9 % ethanol and their mixtures - (40 % and 60 % ethanol). Using 40 % ethanol as extraction solvent resulted in maximum recovery of KBAC. A mathematical model for the solid-liquid extraction from lavender materials was developed. The values of the model parameters were determined using the Regular regime method. A four-parameter empirical model for prediction of the effective diffusivity, Deff, was also applied. The model adequacy was experimentally verified. Based on the theoretical and experimental results KBAC recovery the following extraction conditions were recommended: extraction time - 30 min, temperature - 30 ℃, liquid-solid ratio - 0,01 m3 kg-1 and 40 % ethanol as an extraction solvent. [ABSTRACT FROM AUTHOR]