The global textile industry is increasingly focused on reducing the environmental footprint of synthetic dyes, making a switch to bio-based dyeing materials a key priority for sustainable textile applications. This work describes the preparation of eco-friendly, high-performance dye-doped polymer (DDP) films using a natural dye extracted from Mirabilis jalapa (MJ) (four o’clock flower), embedded in a polyvinyl alcohol (PVA) polymer. Purple-colored composite films were fabricated using a green aqueous extraction method and a low-cost solution-casting technique and were reinforced with chitosan to protect against antimicrobial instability. FTIR spectroscopy revealed shifts in the O–H stretching band following MJ dye incorporation, indicating changes in the hydrogen-bonding environment and intermolecular interactions within the PVA matrix. X-ray diffraction (XRD) analysis showed a reduction in the characteristic PVA diffraction peak at 2θ ≈ 19.5°, indicating a decrease in the structural ordering of the polymer chains. This structural transition is also reflected in a dramatic reduction of the characteristic XRD diffraction peak at 2θ ≈ 19.5o, and the increase of the Urbach energy (Eb) from 0.3315 to 1.0342 eV. Optical characterization shows a pronounced redshift in the absorption spectra after dye incorporation, indicating a transition from an insulating to a semiconducting regime. The optical energy gap (EG) was significantly modified, that is 6.05 eV in the pure PVA material and decreasing to 3.65 eV for the highly dye doped PVA materials. Furthermore, the MJ dye increased the refractive index, dielectric constant, and plasma frequency, indicating improved light-matter interaction and charge-carrier density. The PVA: MJ dye-doped films have a high figure of merit (FOM) and optimized thermal emissivity, making them versatile and sustainable materials for advanced technologies, such as organic light-emitting diodes and flexible photonic sensors. The outcomes of this study establish that green chemistry and optoelectronic engineering are a scalable pathway to functional macromolecules without the ecological footprint of the petroleum-based additives. Clinical trial number Not applicable.
The integration of advanced nanomaterials into cementitious matrices frequently encounters severe particle agglomeration in alkaline pore solutions and prohibitive processing costs that hinder commercial adoption. Here, we synthesize an electrosterically stabilized hydroxyapatite–chitosan (HAp-CS) nanocomposite (approx. 5:1 weight ratio) via in-situ co-precipitation to accelerate hydration kinetics and enhance compressive performance at trace addition levels. HAp-CS nanorods were incorporated into ordinary Portland cement at dosages from 100 to 2000 ppm, alongside standalone 1000 ppm HAp and chitosan controls to isolate biopolymer–nanorod synergy. Dynamic light scattering and solid-state phosphorus EDS mapping verified that chitosan encapsulation prevents nanorod flocculation at high alkaline pH. Isothermal calorimetry revealed that the 1000 ppm dosage advanced the primary hydration peak by 6.4 h (a 37.2
Morupule B coal fly ash was evaluated as a secondary rare-earth-element (REE) resource by integrating the complete experimental record with X-ray diffraction (XRD), ICP-OES mass balance, machine learning, and uncertainty-guided experimental design. The source XRD pattern identifies a refractory mullite–quartz assemblage with trace iron oxides. All nine ICP-OES digestion records were retained, including four non-detects, and the recorded triplicates were recalculated before use. The dysprosium digest mean is 0.04168 mg L^-1 from the three raw replicates rather than the inconsistent tabulated value, whereas the high erbium signal is retained but treated as requiring independent confirmation. After carrying the documented digestion dilution and leaching mass/volume through the balance, direct HCl extraction at 25^∘C is in the single- to low-double-digit range rather than above 100
Interface and bulk defects are detrimental for the performance of 4H-Silicon Carbide (4H-SiC) electronic devices and thermal annealing is an essential procedure for the defects’ passivation and material optimization. In this study, we explore the impact on defectiveness of high-pressure (800 PSI ≈ 55 bar) thermal annealing in oxygen and helium atmospheres at 400 °C on 4H-SiC by examining exciton lifetimes. Three wafer types, representing different stages of device processing, were analyzed: (A) a bare epitaxial layer, (B) an oxide-coated sample, and (C) a sample that underwent post-oxide deposition annealing in nitric oxide (NO). Photoluminescence decay measurements after O₂ annealing show an increased exciton lifetime for the oxide-covered sample, a significant reduction for the bare epitaxial layer and no effects for NO post-deposition annealed sample. Comparisons with helium-annealed samples highlight the influence of oxygen in low-temperature annealing of SiC, presenting O_2 -based processing as a promising starting point for developing alternative post-deposition annealing methods.
Water scarcity has been a pressing crisis in quite a few cities globally. For addressing the urgent demand for water harvesting, a hybrid-wettability surface was fabricated on a copper-based substrate, integrating cactus spines, triangular cactus thorns, and pine needle-derived structures as primary water transport channels, secondary channels, and droplet shedding channels, respectively, for fog-water collection. The superhydrophobic part was fabricated through a two-step process involving rapid laser marking ablation and subsequent chemical modification with a fluorosilane coating, whereas the superhydrophilic patterns were obtained by subjecting the as-prepared superhydrophobic surface to secondary laser ablation. Compared with the untreated copper substrate, the pattern enhanced the fog collection efficiency by 105.21
