Perfluoroalkyl and polyfluoroalkyl substances represent a broad class of synthetic organic chemicals of industrial origin. They have applications in several fields, such as textile and packaging impregnation and coatings, electroplating, and fire-fighting foams, due to their excellent performance. Due to the high strength of the covalent bond between carbon and fluorine, these compounds are frequently designated as “forever chemicals”. They exhibit remarkable environmental persistence, leading to uncontrolled accumulations, and are thus considered harmful. From an eco-friendly perspective, the compelling challenge is generating a textile and packaging coating possessing hydrophobic and oleophobic properties without the hazardous fluorinated additives. The present work introduces the development of a hybrid modelling methodology to evaluate solid surface tension for textiles using Neumann’s equation of state alongside finite element method algorithms and experimental contact angle data. The aim is to provide a predictive tool for assessing optimal non-polluting and non-harmful coating conditions. Indeed, the estimation of solid surface tension – a crucial property in wetting, adhesion, and adsorption processes, which currently lacks direct measurement methods – will be employed to address the selection of those safe and sustainable coating materials and additives that perform better. Perfluoroalkyl and polyfluoroalkyl substances will not be used, contributing to ecological and environmentally friendly solutions.
Polycrystalline α-alumina / yttrium-aluminum garnet (YAG) fibers were prepared from aqueous solutions of aluminum formoacetate and yttrium acetate, using α-Al 2 O 3 nanoparticles as a seeding material. α-Al 2 O 3 /YAG fiber production was achieved via dry-spinning with polyvinylpyrrolidone as a spinning aid, followed by calcination and sintering of as-spun fibers at various temperatures, dwell times and heating rates. X-ray diffraction (XRD) revealed the formation of transitional Al 2 O 3 and yttrium-aluminum perovskite (YAP) phases between 1000 and 1300 °C, with complete conversion to α-Al 2 O 3 / YAG (76 / 24 wt%) achieved at 1500 °C. Full densification required temperatures of at least 1400–1500 °C keeping a sufficient dwell time (30 min), though higher sintering temperatures promoted grain growth. Average tensile strength and creep factor m of the related fibers were tailored by adjusting thermal treatment parameters. At 1400 °C, fibers exhibited higher strength (up to 1149 MPa, m = 0.57), whereas at 1500 °C, they demonstrated enhanced creep resistance (up to 906 MPa, m = 0.69).
We report infrared absorption coefficients of human stratum corneum (SC) from both native ex vivo tissue and in vitro skin models. While the optical properties of human SC have been extensively characterized in the visible and near-infrared spectral ranges, data on its mid-infrared (Mid-IR) absorption characteristics remain limited and largely qualitative. By using transmission infrared (IR) spectroscopy, we provide a quantitative dataset of Mid-IR absorption coefficients. Furthermore, we investigate the dependence of the absorption coefficients on sample hydration offering insights into how water content influences Mid-IR optical properties. The SC shows a good transparency in the so-called molecular fingerprint region (1500 to 950 cm), even in high relative humidity conditions. Our results show that native and in vitro SC exhibit nearly identical spectra, with only minor deviations that can be attributed to chemicals used for fixation of the native skin. With our results, we provide a quantitative foundation for understanding the interaction of Mid-IR light with skin. As the primary interface for incident light, data on the SC's absorption provides also a basis for advancing noninvasive Mid-IR applications in biomedical sensing and dermatological research.
Sustainable recycling of lithium iron phosphate (LFP) cathodes is essential to process battery waste, thus reducing resource depletion and lowering the carbon footprint of battery production. This study introduces a contactless delamination process using high-frequency induction heating to partially decompose the water-based carboxymethyl cellulose and styrene-butadiene rubber binders in LFP electrode production scrap within a temperature range that avoids damage to the LFP. Eddy currents induced in the aluminum current collector enable localized heating at the LFP composite-foil interface, allowing clean separation without toxic solvents or high-temperature furnaces. Variation of the process parameters showed that moderate heating (similar to 240 degrees C) weakens binder adhesion effectively while preserving the integrity of the LFP. Electrodes were fabricated from the recovered LFP composite and evaluated in lithium metal half cells. The best-performing recovered sample (240 degrees C with added conductive carbon) achieved similar to 96 % of the discharge capacity of a recovered sample delaminated without the inductive heat treatment. These results confirm that inductive delamination, with careful temperature control, enables the recovery of high-quality LFP composite suitable for reuse. This method avoids the use of hazardous chemicals and is compatible with roll-to-roll processing, offering a scalable and environmentally-friendly route for direct cathode recycling.
The development of high-modulus glasses is essential for advanced lightweight applications, requiring a fundamental understanding of how different oxide components dictate elastic performance. To maximize stiffness, oxides must be strategically introduced to enhance both network connectivity and volumetric packing density; hence, Y 2 O 3 , ZnO, and CeO 2 are investigated here due to their high single-bond dissociation energies and strong cationic field strengths. Magnesium aluminosilicate glasses (MAS) modified with Y 2 O 3 , ZnO, and CeO 2 were systematically investigated to establish composition–structure–property relationships. A constrained ternary mixture design (Y 2 O 3 –ZnO–CeO 2 = 14 wt.%) was used to span the compositional space efficiently. The measured Young’s modulus ranged from 97.5 to 113.8 GPa, while the specific modulus varied between 36.6 and 41.7 ×10 6 N·m/kg. The highest values were obtained for compositions adding Y 2 O 3 alone or Y 2 O 3 –ZnO. Raman spectroscopy revealed systematic changes in the Si–O stretching band, including shifts in band position and variations in band width depending on composition. These changes indicate structural reorganization of the glass network. A moderate correlation between Raman peak position and Young’s modulus confirms that structural connectivity effects contribute to stiffness, although additional factors such as packing density and cation field strength are also relevant. The results demonstrate that Y 2 O 3 is the most effective oxide for increasing stiffness, ZnO exhibits composition-dependent behaviour, and CeO 2 reduces the specific modulus. The combined analysis provides an experimental and structural basis to designing high-modulus glass systems.
