Ultrasonic interferometric analysis of molecular interactions in nano-coatings on metallic surfaces: A review

• Ultrasonic interferometry resolves nanoscale molecular interactions in coatings. • Acoustic parameters predict coating stability, adhesion, and durability. • Links thermoacoustic behavior to anticorrosion, self-cleaning, and antimicrobial effects. • Applicable across marine, biomedical, aerospace, and structural industries. The rapid development of nanotechnology has allowed the creation of nano-engineered coatings that adequately enhance the functional performance of metallic surfaces by offering corrosion resistance, self-cleaning capability, and antimicrobial durability. The long-term efficiency of such coatings, however, will fundamentally be dependent upon the molecular interactions that critically determine their structural stability, adhesion behavior, and environmental responsiveness-all factors usually difficult to determine with conventional methods of surface analysis. This review highlights the novel integration of ultrasonic interferometry as a molecular-level diagnostic tool for nano-coating analysis. The measurement of acoustic parameters including ultrasonic velocity, acoustic impedance, compressibility, free volume, Gibbs free energy, and relaxation time by ultrasonic techniques presents a non-destructive, highly sensitive method to quantify the intermolecular forces along with nanoscale packing density within the coating matrices. Such information enables forecasting and improvement in the performance of coatings before field deployment. The originality of the work consists in relating thermoacoustic parameters with actual functional behaviors of nano-coatings in diverse application sectors, which include marine transportation, biomedical devices, aerospace components, and architectural structures. This review also attempts to highlight the recent challenges in the acoustic interpretation at the nanoscale and points out some bright perspectives concerning the application of AI for ultrasonic signal processing, adaptive self-healing coatings, and in-situ monitoring systems. In summary, this work will show that ultrasonic analysis could provide a strategic framework for the systematic design, characterization, and enhancement of next-generation nano-coatings deposited onto metallic surfaces. Ultrasonic assisted nano-coating on metallic surface