The development of safe and sustainable coatings derived from food by-products represents an important strategy within circular bioeconomy frameworks. In this study, high internal phase Pickering emulsions (HIPEs) were developed using ultrasound-modified high-methoxyl pectin extracted from citrus processing waste combined with commercial zein from maize. The resulting polysaccharide–protein complexes were investigated as stabilizing particles for oil-in-water emulsions intended for edible coating applications on fresh-cut pineapple. Pectin (2.0% w/v) was extracted from citrus fresh-produce waste and structurally modified using high-power ultrasound. The modified pectin was subsequently combined with increasing concentrations of zein (0.0–2.0% w/v) to form pectin–zein complexes that stabilized emulsions with a fixed oil fraction (φ = 0.6). The influence of environmental pH on emulsion stability was evaluated by measuring droplet size distribution and ζ-potential at pH 4, 7, and 10 using electrophoretic light scattering (Zetasizer Nano, Malvern Instruments Ltd., UK). Results demonstrated a strong pH-dependent stability of the Pickering emulsions. The smallest droplet sizes were observed at pH 4, where positively charged zein interacts electrostatically with negatively charged pectin, promoting the formation of strong interfacial complexes and enhanced emulsion stability. Near neutral pH (≈7), close to the isoelectric point of zein (pI ≈ 6.2–6.8), electrostatic interactions weakened due to partial charge neutralization, resulting in increased droplet growth, aggregation, and reduced stability. Under alkaline conditions (pH 10), both pectin and zein carried negative charges, leading to electrostatic repulsion and a renewed decrease in droplet size. At this pH, stability was primarily governed by repulsive forces, as confirmed by the more negative ζ-potential values, although interfacial cohesion between biopolymers was reduced compared with acidic conditions. Overall, the findings highlight the critical role of environmental conditions, as the pH, in modulating polysaccharide–protein interactions and the stability of pectin–zein Pickering emulsions. These results support the potential of ultrasound-modified citrus pectin and zein as sustainable stabilizing particles for the design of circular edible coatings and thin films based on high internal phase emulsions.

Quantifying the thickness of thin coatings on rough substrates is essential for process control but usually relies on destructive cross sections or techniques that assume laterally uniform films. We present a non destructive framework that estimates deposited thickness from paired top down SEM images acquired before and after coating, targeting films that are thin relative to the lateral spacing of surface features. In the analytic route, we treat coating as an effective geometric dilation of substrate features. For binarized images, the increase in bright area, normalized by the average of the pre and post deposition perimeters, yields a first thickness estimate. An overlap correction is introduced to account for feature coalescence after deposition, which would otherwise bias the estimate upward when asperities merge. Tests on synthetic shapes and numerically generated rough landscapes show that the corrected estimator reduces both bias and variance, with robustness improving for surfaces with larger correlation lengths. Application to experimental SEM pairs from coated rough substrates gives thickness values consistent with independent indications. Two machine learning modules complement the analytic approach. A supervised regressor that ingests before and after images together with difference channels predicts an effective dilation length calibrated to nanometers and reduces sensitivity to segmentation choices. A U-Net model performs an internal consistency check by reconstructing a plausible pre deposition image from a post deposition image and a scalar thickness, supporting the thickness as dilation interpretation for the explored coating and roughness ranges.

Sustainability in engineering systems is strongly influenced by corrosion, as material degradation directly affects component lifetime, maintenance requirements, and recyclability. This is particularly critical for aeronautical components, where durability, reliability, and environmental performance are essential. Protective coatings are widely employed to prevent corrosion, with hard chromium (Cr) plating traditionally used in the aeronautical industry due to its excellent mechanical and wear properties. However, increasing environmental and health concerns associated with hard Cr processes have created significant pressure to develop safer and more sustainable alternatives.

In this context, Ni-based coatings have emerged as promising alternatives. Their properties can be tailored either through alloying element additions or by incorporating strengthening particles to enhance mechanical performance. Nevertheless, improvements in mechanical properties often come at the expense of electrochemical performance, as alloying additions or particle incorporation may negatively affect corrosion resistance. Thus, in this work, we investigate the effect of incorporating Sn as an alloying element or ZrO₂ particles as a reinforcing phase on the corrosion behavior of Ni-coated steel in a 3.5% NaCl solution. The objective is to establish a structure–corrosion relationship by correlating microstructural characterization with potentiodynamic polarization measurements. The results indicate that, for Ni–Sn coatings, the Sn content plays a critical role in determining corrosion performance. Similarly, for Ni–ZrO₂ composite coatings, a threshold in particle concentration governs the electrochemical response. These findings provide insight into optimizing Ni-based coatings for enhanced corrosion resistance, contributing to more sustainable surface engineering solutions for aeronautical applications.

Fraunhofer IME’s Natural Product Department specializes in bioactive molecule discovery, leveraging a premier collection of over 130,000 microbial strains. Utilizing a platform inherited from decades of industrial research, the department manages the full workflow from strain to purified product. This integrated pipeline translates innovation into marketable solutions across diverse sectors, including healthcare, nutrition, and specialized applications like sustainable antifouling.

Fraunhofer IME provides a highly adaptable research framework. Partners can choose a single project entry point or combine all three into a comprehensive discovery program:

• Biobank Screening: Utilizing our microbial library of over 130,000+ microbes to identify novel bioactive scaffolds.
• Advanced Cultivation: Applying cutting-edge technologies (e.g., droplet-microfluidics and biomimetic environments) to isolate underexplored species from complex holobionts, such as coral reef and sponge microbiomes.
• Direct Analytics: Deploying our versatile analytical pipeline to investigate external biological matrices—learning directly from nature how organisms like marine sponges prevent fouling through chemical defense.

This approach provides access to a vast chemical space significantly superior in diversity and complexity to standard synthetic libraries. Crucially, these natural sources are inherently ecologically friendly and sustainable—a characteristic highly prioritized for next-generation antifouling agents. Furthermore, our pipeline is optimized for minimal sample requirements, ensuring efficient characterization even with limited material. Backed by comprehensive natural product databases and state-of-the-art metabologenomic tools, Fraunhofer IME provides a goal-oriented platform to turn innovation into sustainable, marketable products tailored for global challenges.

Nano-enabled coatings have emerged as advanced solutions for diverse coating applications. By manipulating materials at the nanoscale, these coatings provide enhanced properties, e.g. durability, corrosion resistance, self-cleaning, hydrophobicity or antimicrobial activity to metals, glass, ceramics, and textiles. Not only they offer advanced performance but also act as substitutes to traditional coatings linked to toxicity, such as hard chromium. However, they also must be shown to be safe alternatives, in order to avoid regrettable substitutions.

Originating from the EU’s Chemicals Strategy for Sustainability, the Safe and Sustainable by Design (SSbD) concept aims to offer a novel approach in guiding innovation away from harmful substances towards sustainable, competitive alternatives. The EU has been working on an actionable framework to facilitate the process. The SSbD framework is still under development, but has already offered opportunities, and challenges to European researchers, industry and regulators.

In my presentation, I will be giving examples of research focussing on performance and properties of nano-enabled coatings along with data on their behaviour, both as pristine, as well as aged, in scenarios that simulate their life cycle. I will be emphasising that understanding fundamental behaviour at the nanoscale, offers new tools to predict coating behaviour, toxicity and sustainability in tandem, supporting, facilitating and streamlining the SSbD approach.

Acknowledgment: The work was supported by European Union's Horizon 2020 research and innovation program (SABYDOMA Project, GA-862296) and Horizon Europe UKRI Guarantee (MOZART Project, GA-101058450).

Plating on plastics (PoP) is broadly used in automotive, electronics, and household appliances to improve mechanical strength, corrosion protection, and surface aesthetics. Effective pretreatment of polymer surfaces is required to enable electroless deposition of a conductive Ni-P layer, which acts as the foundation for subsequent electroplating. However, established industrial processes depend on Cr⁶⁺-based etching solutions and Pd-containing activators, raising serious environmental, health, and economic concerns due to the toxicity of Cr⁶⁺ and the high cost of Pd. Among polymeric materials, ABS and polyamides (e.g. PA6, PA66, PA12) are most frequently used in PoP applications.

In this study, chromic acid etching is replaced by an enzyme-based pretreatment using a protease (alcalase) and Pd-based activation is replaced by Ni salt-based activation which is more cost-effective. Alcalase is an alkaline serine protease capable of cleaving amide bonds and was therefore selected for the enzymatic pretreatment of PA12 surfaces, introducing polar functional groups that promote effective activation for subsequent electroless Ni-P deposition. The enzymatic pretreatment conditions were systematically optimized by varying the enzyme-containing solution temperature, enzyme concentration, and immersion time. Surface chemistry, morphology and adhesion were evaluated by FT-IR spectroscopy, water contact angle measurements, SEM/EDS and pull-off adhesion tests. The results showed the formation of uniform, thin and well-adhered Ni-P conductive layer on enzyme-treated PA12 substrates, highlighting the potential of protease-assisted pretreatment as a sustainable alternative for PoP.

An important challenge faced by the automotive industry concerns the so-called overspray, when excess paint particles disperse and contaminate the surrounding environment. To minimise the potential damage caused by overspray to the painting robots, these are often protected by polyester covers. However, their hydrophilic nature leads to paint absorption, requiring their often replacement and subsequent waste generation. A promising solution to deal with this problem is to impart the covers with superhydrophobic properties. In superhydrophobic surfaces, the drops of water are almost
spherical, so they will readily roll off. When exposed to paint particles, the paint should behave similarly, not having time to be absorbed.
In this work, several modification strategies were explored to impart polyester fabrics with highly hydrophobic features through the combination of nanomaterials (silica and alumina nanoparticles) to introduce a micro/nano roughness and the use of low surface free energy compounds (stearic acid and hexadecyltrimethoxysilane). Results showed that, overall, the immobilisation of polyester samples with nanomaterials alone increased the water contact angle, but the water droplets did not roll from the surfaces. Such hydrophobic features were attributed to the increase in fibres' roughness, as evaluated by SEM analysis and roughness measurements. When nanomaterials were combined with hydrophobic agents, the hydrophobic properties of polyester fabrics improved synergistically, as evidenced by the increase in the water contact angle but also by the decrease in the water sliding angles. It was also possible to conclude that any of the modification strategies improved the fabric’s ability to resist the effects caused by overspray, as there was a significant reduction in the amount of paint absorbed. Results also suggested that the approaches with the lowest sliding angles had better resistance against the effects caused by overspray. The durability of the best effective treatment was evaluated by measuring the water contact angle after 70 washing cycles, and results showed that hydrophobicity could be preserved even after being subject to these harsh conditions.
In conclusion, combining nanostructured materials with hydrophobic agents holds great potential to create highly hydrophobic features and subsequent resistance to overspray. This minimizes the need for frequent replacements, reduces painting process delays and costs and reduces the waste produced.

The MOZART project brings together partners from both industry and academia to address the challenging task of replacing hard chromium (HC) plating with a REACH‑compliant alternative capable of delivering comparable performance.[1] Chromium trioxide, the basis of HC coatings, is classified as carcinogenic, mutagenic, and sensitizing to skin and respiratory pathways, and must therefore be phased out under REACH. Nickel plating, already widely used in industry, represents a less harmful option, and literature demonstrates that nickel‑based metal matrix composites (MMCs) reinforced with hard ceramic particles can achieve hardness values close to those of HC coatings (≈1200 HV). Nevertheless, conventional nickel baths still present toxicity concerns, particularly due to the use of boric acid as a buffering agent, which is considered toxic to reproduction.[2]

In this context, Politecnico di Milano, as a partner of the MOZART project, developed nickel‑based nanocomposite coatings reinforced with hard ceramic nanoparticles using electrodeposition from a succinic acid bath. Succinic acid, a di‑carboxylic acid with dissociation constants of 4.2 and 5.6, provides effective buffering around the operating pH of 4.6, eliminating the need for boric acid. The most promising results were obtained by co‑depositing boron carbide nanoparticles within the nickel matrix. Optimal conditions were identified as 10 g/L of dry nanoparticles dispersed in the electrolyte using sonication and a current density of 30 mA/cm², with a total charge exchanged of 36 C.[3] From a tribological perspective, the coating exhibited a coefficient of friction (CoF) of 0.12 under dry sliding conditions, which remained stable until progressive reduction of the surface roughness occurred as a result of continuous sliding. These findings highlight succinic acid‑based electrolytes as a viable, REACH‑compliant pathway toward sustainable, high‑performance tribological MMC.

[1] European Union, Mozart project [Online]. Accessed on 10th December 2025. Available at https://www.mozart-project.eu/# n.d.

[2] European Chemicals Agency, Understanding REACH [Online]. Accessed on 10th December 2025. Available at https://echa.europa.eu/regulations/reach/understanding-reach n.d.

[3] Zoia F, Bernasconi R, Afzali P, Lopez LM, Magagnin L. Electrodeposition of REACH compliant boron carbide reinforced nickel composites for wear protection. Surf Coat Technol 2026;520:132996. https://doi.org/10.1016/j.surfcoat.2025.132996.

Metal Matrix Composites (MMCs) constitute an important class of engineered materials designed to overcome the inherent limitations of pure metals, particularly in terms of mechanical strength, wear resistance, corrosion protection, and tribological performance. By incorporating reinforcing phases like hard ceramic particles or 2D solid lubricants into a metallic matrix, MMCs can achieve enhanced functional properties that are difficult to obtain through alloying or conventional surface treatments alone.[1]

The development of such coatings, however, must comply with increasingly stringent environmental and health regulations. Within this context, the European project MOZART aims to deliver REACH-compliant alternatives to hard-chrome (HC) coatings by developing nickel-based MMCs capable of matching HC performance.[2] Because boric acid, a common buffering agent in commercial nickel baths, has been classified as a substance of very high concern (SVHC) due to its reproductive toxicity, safer substitutes are required. Literature reports that di- and tri-carboxylic acids such as citric acid are effective buffering agents within the operative pH range of nickel baths (pH 3–5).[3]

In this work, succinic acid is proposed as a sustainable buffering agent for the electrodeposition of nickel-based MMCs reinforced with molybdenum disulphide (MoS₂) nanoparticles. Successful co-deposition requires stable nanoparticle dispersions in the electrolyte; therefore, several surfactants were evaluated to mitigate MoS₂ agglomeration and promote uniform incorporation into the deposit.[4] The influence of each surfactant on bath stability, deposition efficiency, and the resulting co-deposition behaviour was investigated to assess whether MoS₂ incorporation effectively provides solid lubrication, reduces the coefficient of friction, and enhances the wear resistance of the resulting composite coatings.

[1] Wasekar NP, Lavakumar B. Strengthening mechanisms and tribological aspects of ceramic particle reinforced electrodeposited metal matrix composites – A review. J Alloys Compd 2025;1037:182288. https://doi.org/10.1016/j.jallcom.2025.182288.

[2] European Union, Mozart project [Online]. Accessed on 10th December, 2025. Available at https://www.mozart-project.eu/# n.d.

[3] Bigos A, Wolowicz M, Janusz-Skuza M, Starowicz Z, Szczerba MJ, Bogucki R, Beltowska-Lehman E. Citrate-based baths for electrodeposition of nanocrystalline nickel coatings with enhanced hardness. J Alloys Compd 2021;850:156857. https://doi.org/10.1016/j.jallcom.2020.156857.

[4] Liu C, Zhen H, Huang Q, Chen W, Mai Y, Zhang L, Jie X. Improvement in Tribological and Anticorrosion Performances of Co-MoS2 Composite Coatings. J Mater Eng Perform 2023;32:2237–48. https://doi.org/10.1007/s11665-022-07260-y.

Poly(butylene succinate) (PBS) is a bio-based and biodegradable aliphatic polyester that has attracted increasing interest as a sustainable binder for coating applications. Despite its favorable environmental profile, the moderate mechanical strength, thermal resistance, and barrier performance of PBS can restrict its use in demanding coating systems. In this study, biochar (BC), a low-cost carbon-rich material derived from biomass, was employed as a functional filler to tailor PBS properties, with emphasis on the role of biochar functionalization and its impact on coating-relevant performance. PBS/BC composites containing low biochar loadings were prepared via melt-mixing, an industrially scalable and solvent-free processing route. Mechanically and chemically functionalized biochar was incorporated to enhance filler dispersion and interfacial interactions with the polymer matrix. The effect of biochar functionalization on the structural, thermal, mechanical, and biodegradation behavior of PBS was systematically investigated. Crystallization behavior and thermal transitions were analyzed using differential scanning calorimetry (DSC) and X-ray diffraction (XRD), while tensile testing was employed to assess mechanical performance. The results show that appropriately functionalized biochar enhances stiffness, thermal stability, and crystallinity of PBS at low filler contents, indicating effective reinforcement and nucleation effects. These property enhancements, together with controlled biodegradation behavior, highlight the potential of PBS/biochar composites for sustainable coating applications requiring balanced performance and environmental compatibility.

Acknowledgements

The research work was supported by the project SUB1.1 Research Excellence Partnerships-REP, under the National Recovery and Resilience Plan Greece 2.0 (Strategy for Excellence in Universities & Innovation, ID 16289), Project CircLandfil, ID: ΥΠ3ΤΑ-0559411.