Swart, Nina; Lohrentz, Luca; Brink, Hendrik Gideon (Springer, 2025-07)
Polyaniline-naphthalene-sulfonic acid (PANI-NSA) nanotubes were synthesized and evaluated in this preliminary study for Cr(VI) removal from synthetic wastewater. SEM analysis showed that optimized synthesis conditions produced uniform nanotubes with additional surface spheres, potentially enhancing adsorption performance. Adsorption isotherms (Redlich-Peterson and Langmuir models) suggested a monolayer adsorption mechanism, while kinetic studies (Elovich and Wang two-phase models) indicated chemisorption-driven, diffusion-controlled adsorption. To explore the influence of synthesis conditions, temperature and water volume (as reaction eluent) were varied. PANI-NSA synthesized at 5 °C with 80 mL of water (more dilute) had an adsorption capacity of 374.9 mg g⁻1 (66.72% removal), increasing to 438.2 mg g⁻1 (79.28% removal) at 15 °C with 20 mL of water (i.e. more concentrated). While these results highlight promising trends, further detailed characterization and adsorption optimization studies are required to fully assess scalability and long-term application in industrial Cr(VI) remediation.
Allan, Lynet; Mwabora, Julius M.; Mulwa, Winfred M.; Mapasha, Refilwe Edwin; Musembi, Robinson J. (Springer, 2025-12)
This study explores the structural, mechanical, electronic, lattice dynamical, and thermal properties of the half-Heusler ZrPtSn using first-principles density functional theory. The goal is to assess its suitability for electronic and thermoelectric applications. Structural optimization confirmed stability under ambient conditions. Mechanical properties, including bulk, shear, and Young’s moduli, were evaluated for stiffness and ductility. Electronic structure analysis determined its semiconducting nature, with band gaps of 1.10 eV (without SOC) and 0.95 eV (with SOC). Phonon dispersion was analyzed to assess dynamical stability. ZrPtSn was dynamically stable, with no imaginary phonon modes. Its band gap suggests potential for optoelectronic applications. These findings provide a comprehensive understanding of ZrPtSn’s properties, supporting its potential use in electronic and thermoelectric devices and paving the way for further experimental and theoretical studies.
