Announcements

1. “Glutamate- and Tartrate-Based Inhibitor Films to Prevent Chloride-Induced Corrosion in Reinforced Concrete: Efficiency of Dry or Hydrated Films via Molecular Dynamics Simulations”
by Giuseppina Raffaini, Michelina Catauro, Fabio Bolzoni and Marco Ormellese
Coatings 2025, 15(1), 37; https://doi.org/10.3390/coatings15010037
Available online: https://www.mdpi.com/2079-6412/15/1/37

Cover Story: Organic inhibitors have been proposed to prevent chloride-induced corrosion in reinforced structures. The homogeneous and stable films on carbon steel and the electrostatic repulsion to chloride ions over time are crucial aspects of their performance. The changing of small organic molecules into passive films by self-aggregation to prevent chloride penetration is important to consider in the design of possible efficient green coatings. The intermolecular interactions of the glutamate- and tartrate-based inhibitor films under dry and hydrated condition are studied via atomistic molecular dynamic simulations.

2. “Preparation and Characterization of Mg-Based Biomaterials with Bioactive Surfaces Functionalized with EU/Gd NPs for Bone Tissue Regeneration Obtained via PEO Process”
by Klaudia Kuźmiak, Łukasz Janus, Aleksandra Sierakowska-Byczek and Julia Radwan-Pragłowska
Coatings 2025, 15(2), 124; https://doi.org/10.3390/coatings15020124
Available online: https://www.mdpi.com/2079-6412/15/2/124

Cover Story: This study focuses on developing magnesium-based biodegradable implants with enhanced bioactivity through surface modification via plasma electrolytic oxidation (PEO) with rare earth ions (Eu/Gd nanoparticles). Magnesium’s light weight, biocompatibility, and bone-like mechanical properties make it a titanium alternative, particularly in pediatric surgery, due to its natural degradation within the body. However, its high reactivity in physiological environments requires surface modification to reduce biocorrosion. Here, the PEO process was used to successfully create a protective coating, limiting biodegradation and magnesium ion release. Characterization tests showed high hydrophilicity, a favorable surface morphology, and excellent biocompatibility, highlighting the potential of modified magnesium implants for biomedical applications.

3. “A Study of the Hall Effect on Doped and Undoped Praseodymium Nickelate Perovskite Thin Films and the Impact of the Reduction Process”
by Alex Misiak, Mufeed Keenari, Yohann Breard, Wilfrid Prellier, Alain Pautrat and Adrian David
Coatings 2025, 15(3), 287; https://doi.org/10.3390/coatings15030287
Available online: https://www.mdpi.com/2079-6412/15/3/287

Cover Story: The following study examines the Hall effect in praseodymium nickelate thin films, focusing on the impact of strontium doping on transport properties. Sr doping enhances transport properties, leading to a transition from semiconducting to metallic behavior. The reduction process and its correlation with transport properties and structural phase change are highlighted. This phase transition induced a change from perovskite to an infinite layer, altering the conduction path from one that is 3D to one that is 2D. Carrier density and mobility are indeed key factors in understanding electronic transport. The infinite layer exhibits semiconducting behavior, with charge carrier concentration and mobility being significantly affected by the reduction process. These characterizations are essential to understanding superconductivity in nickelates.

4. “Novel Bio-Based Formulations for Alkyd Wood Coatings: Effects on Biodegradation and Technical Performance”
by Idoia Etxeberria, Ingemar Svensson, Ana Isabel Díaz and Leire Barruetabeña
Coatings 2025, 15(4), 400; https://doi.org/10.3390/coatings15040400
Available online: https://www.mdpi.com/2079-6412/15/4/400

Cover Story: Bio-alkyd resins were synthetized by replacing phthalic acid with azelaic acid, and were formulated to develop novel wood coatings with enhanced biodegradability. The resulting formulations exhibited good appearance and a natural finish when applied to wood, along with strong adhesion and improved hardness compared to a reference coating. Aerobic biodegradability was assessed in accordance with the ISO 14855-1 standard. This research paves the way for the development of fully bio-based and cobalt-free alkyd coatings combining an improved environmental profile with technical performance properties.

5. “Application of AC-DC-AC Accelerated Aging to Assess the Galvanic Corrosion Risk of Mild Steel Coated with Graphene-Embedded Epoxy Coatings”
by Kazem Sabet-Bokati and Kevin Paul Plucknett
Coatings 2025, 15(5), 501; https://doi.org/10.3390/coatings15050501
Available online: https://www.mdpi.com/2079-6412/15/5/501

Cover Story: Graphene’s incorporation into epoxy coatings raises concerns regarding the galvanic corrosion of metallic substrates due to its high electrical conductivity. In this study, we explore the galvanic corrosion risk of mild steel coated with graphene-embedded epoxy using AC-DC-AC accelerated aging, which simulates real-world delamination by promoting interfacial degradation and ionic transport. Our results showed the minimal risk of cathodic reactions shifting to dispersed graphene within the epoxy matrix, confirming its limited role in galvanic corrosion. While graphene enhanced structural integrity, it weakened adhesion at the steel interface, making the system more prone to delamination. These findings are critical for designing more effective graphene-based coatings, balancing protection and adhesion stability.

6. “The Characterization of Surface Texture in Laser Bamboo Engraving: A Metrological Approach”
by Maria A. Sáenz-Nuño, Cristina Puente and Eva María Rubio
Coatings 2025, 15(6), 624; https://doi.org/10.3390/coatings15060624
Available online: https://www.mdpi.com/2079-6412/15/6/624

Cover Story: Laser engraving is a widely adopted technique for bamboo, yet no standard roughness parameter exists for evaluating surface texture. This study systematically analyzes conventional 2D roughness parameters—commonly used for metals—to assess bamboo surfaces engraved with a pulsed laser (450 nm; 5.5 W) under varying speed and power settings. Using calibrated equipment, we identified the most suitable parameters for accurately characterizing the engraved texture. Unlike previous studies limited by specific materials or laser conditions, we propose two robust 2D parameters—particularly Rz—as reliable indicators of engraving quality across diverse materials and laser setups, enabling consistent, single-measurement evaluations.