Micro

Poly(vinyl alcohol) (PVA) has been widely investigated as a matrix for anti-corrosion coatings because of its continuous film-forming ability, relatively low cost, and the versatility of its hydroxyl groups for chemical modification. However, its high affinity for water remains a major limitation for long-term corrosion protection. Consequently, recent research has increasingly focused on cross-linking, nanostructuring, and functional modification of PVA to improve its resistance to moisture and aggressive environments. This review critically examines recent advances in PVA-based anti-corrosion coatings by integrating coating composition, cross-linking chemistry, micro- and nanostructural features, and electrochemical corrosion-protection mechanisms. Particular attention is given to the effects of glutaraldehyde, boric acid, citric acid, epichlorohydrin, and other multifunctional cross-linkers on network structure, mechanical behavior, water resistance, and barrier properties. The roles of urea, glycerol, inorganic fillers, nanomaterials, corrosion inhibitors, and inhibitor-containing nanocontainers are also evaluated in relation to coating durability and corrosion-protection performance. In addition to describing reported approaches, the review critically compares the influence of substrate, PVA characteristics, cross-linking conditions, nanofiller loading, coating architecture, electrolyte, exposure duration, and electrochemical parameters on the reported performance. Particular emphasis is placed on the relationships between cross-linked network structure, nanofiller dispersion, interfacial adhesion, electrolyte transport, and electrochemical response. The review further considers active inhibition, self-healing strategies, and environmental aspects of PVA-based coatings, while identifying limitations related to moisture sensitivity, long-term durability, and inconsistent reporting of experimental parameters. By integrating composition, cross-linking chemistry, structure–property relationships, and electrochemical evidence, this review provides a critical framework for understanding and designing more durable and environmentally compatible PVA-based anti-corrosion coatings.

Healing wounds and skin lesions has been practiced since ancient times, and various mechanisms have been used to treat them, ranging from bandages and herbs to ointments and modern alternatives such as dressings. This work aimed to develop bioactive dressings for wound healing. Dressings were prepared using the solution-drained plate technique and comprised 2% (w/v) sodium alginate with varying concentrations of Melipona beecheii honey, up to 5% (w/v). The dressings obtained showed suitable flexibility and elongation as the honey content increased, and had a suitable thickness for skin application, ranging from 0.03 to 0.21 mm. They were also evaluated for barrier, optical, structural, thermal, morphological, bioactive, and cytotoxic properties. The dressings demonstrated good moisture absorption and maintained antimicrobial activity for up to 12 months. Moreover, they retained bioactive compounds, demonstrated strong antioxidant activity, and showed biocompatibility in biological assays. The dressings did not induce cytotoxic effects in human keratinocytes. Dressing with a 2.5% honey concentration exhibited physicochemical and bioactive properties that could improve skin wound healing.

This study investigated the synthesis and microstructural evolution of AlFeCoNi medium-entropy alloy powder processed by ball milling, conventional uniaxial pressing, and vacuum sintering at 900 °C for 1 h. The mechanically milled powder exhibited a refined, irregular particle morphology with a broad size distribution, indicating extensive fracture and cold-welding during milling. SEM (scanning electron microscopy) and EDS (energy-dispersive spectroscopy) observations showed effective elemental mixing of Al, Fe, Co, and Ni, with only limited evidence of large-scale segregation, suggesting that mechanical alloying promoted compositional homogenization. After compaction and sintering, the powder compact exhibited noticeable changes in microstructural continuity and pore morphology, indicating further microstructural evolution during thermal treatment. Overall, the results demonstrate the microstructural evolution of AlFeCoNi MEA during ball milling and subsequent conventional sintering, while further investigation involving quantitative densification measurements and optimization of sintering conditions is required to establish the consolidation behavior and microstructural uniformity of the alloy.