Claudio Imparato

Ice accumulation on aircraft surfaces severely affects aerodynamic performance by increasing drag and reducing lift, leading to stall conditions. Conventional thermal and pneumatic anti-/de-icing systems, although widely used, have some disadvantages, including high cost, inefficiency, and environmental unsustainability. Hydrophobic and icephobic coatings have emerged as a promising alternative to reduce ice adhesion and delay ice formation. This paper reviews the use of silane agents in epoxy-based coatings, incorporating functional additives such as natural fibers, quantum dots, and nanoparticles, to enhance hydrophobicity. Results demonstrated that the combination of silanes and functional additives affects surface features and wettability, improving hydrophobicity. These case studies show the potential of this approach in the development of coatings for advanced aircraft ice-protection applications.

The chemical modification of metal oxide surfaces with organic molecules is a versatile strategy to tune their physicochemical and electronic properties, enhancing their efficiency in a range of applications, including catalysis and light harvesting.

Polymers are essential in modern life, but their large-scale production from non-renewable sources contributes to raw material depletion and environmental pollution. The shift from a linear to a circular economy aims to address these issues by promoting sustainable practices. Recent research focuses on incorporating natural fillers and biowastes to improve flame retardancy and reduce resource depletion. This work demonstrates the suitability of humic acids, biochar derived from both spent coffee grounds and the hydrothermal liquefaction of sludge, for use as flame-retardant additives in epoxy resins. The results are discussed in relation to the composition and preparation procedure of the composite materials. Particularly, the modification of epoxy chains with a proper coupling agent guarantees the uniform distribution of the waste throughout the polymer matrix.

The Digital Image Correlation (DIC) is a non-contact technique that analyses a sequence of images providing full field measurement of displacements and strains over time. The DIC experimental set-up requires a speckle pattern. In this work a new epoxy-based nanocomposite, containing TiO₂ nanoparticles and coffee-derived biochar fillers, was developed to obtain an ecofriendly flame-retardant material with suitable mechanical and optical properties for its use as speckle pattern for DIC applications. The optimized formulation is characterized by a uniform distribution of TiO₂ and biochar particles and can be employed as self-standing material during the manufacturing of composite reinforcements. The physicochemical properties, mechanical behaviour and fire performances of the nanocomposite are described. The incorporation of the additives in the epoxy resin increases the Young’s modulus by around 30% and almost doubles the burn-through time with respect to pristine resin, suggesting a slight condensed phase mechanism arising from the synergistic action of TiO₂ and biochar. The effectiveness for creating DIC speckle patterns is validated by comparing the experimental strains measured by means of DIC analysis with those obtained through a traditional technique. Finally, the durability of the speckle patterns was assessed by accelerated thermal aging tests, confirming the potential application of the material in structural health monitoring of composite structures.