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The effect of autohydrolysis (AH) temperature (165 °C, 195 °C, 225 °C) on the structure, purity, and recovery yield of the cellulose residue isolated after additional alkaline and bleaching steps from wheat straw, was investigated. The processes were quantified for mass yields in the different steps and for antioxidants and sugars release during AH. AH at 195 °C allowed for the highest cellulose residue yield (83.5%) with purity (∼70%) and structure similar to the other residues. FTIR and XRD analyses showed straw cellulose (SC) with a type II polymorphism and crystallinity index increasing with AH temperature. SC obtained at the end of the entire fractionation process (SC-195 °C) starting from AH residue-195 °C was tested as a reinforcing agent in different percentage (0, 2 and 5% by weight) in poly(butylene adipate-co-terephthalate) (PBAT) films. The Young’s modulus of the films increased by ∼17% with 5 wt% cellulose, while tensile strength and elongation at break decreased.

Fluid balance is important for a healthy human being. In this paper, a method to measure hydration status was developed and tested towards non-invasive measurement from human skin. Measurement of hydration status was performed by a microwave sensor utilizing a complementary split ring resonator (CSRR). The sensor was modeled, manufactured and then characterized by measuring tailor made skin phantoms based on the realistic electrical properties of skin with different degrees of hydration status. Qualitative longer term (>24 h) evaluation of the sensor was also performed by measuring polyester tissue that was drying over the time. Hydration status, represented by dehydrated, normal and hydrated skin phantoms, based on polyurethane with carbon and ceramic additives, was measured successfully by monitoring the changes in resonance frequency around 5.52 GHz. All results were compared to the dielectric reference measurements done by a commercial laboratory instrument.