Lead zirconate titanate aerogel composite coatings with lightweight structure, excellent mechanical and integrated electrical properties for underwater acoustic transducers.

Lead zirconate titanate (PZT) aerogels are ideal piezoelectric materials for underwater acoustic transducers (UATs) due to their light structure, but their difficult preparation, poor mechanical properties and poor integrated electrical properties greatly limit their practical applications. In order to overcome these difficulties, we innovatively adopted a solvothermally combined sol-gel method to successfully achieve simple, rapid, and low-cost preparation of PZT aerogels, designed a 0–3 type PZT aerogel/PVDF composite coating to overcome the weak mechanical properties of PZT aerogels, and used SiO 2 aerogels and PZT ceramic powders to improve the ferroelectric and piezoelectric properties of the PZT aerogel/PVDF composite coating, respectively. After verifying that the PZT aerogel/PVDF composite coating modified by 4 wt% SiO 2 aerogels and 30 wt% PZT ceramic powders has the best integrated electrical properties, we prepared its 50-layer combination to further improve the comprehensive properties. The 50-layer composite coating has a moderate piezoelectric constant d 33 of 132.7 pC/N and a high piezoelectric constant d 31 of −33.6 pC/N, a low relative permittivity of 593.7 and a low dielectric loss of 0.85% at 40 Hz, a high Young's modulus of 616.2 MPa, and a density of 1.163 g/cm3 similar to water, indicating that it has surpassed various high-performance Pb-containing piezoelectric ceramics in integrated electrical properties, mechanical properties and acoustic impedance matching with water, which is more in line with the needs of use in UATs. This research offers a new pathway to design a piezoelectric material for UATs with light structure and excellent comprehensive properties. • Solvothermal combined with sol-gel method overcomes the bottleneck that PZT aerogels are difficult to prepare. • PZT aerogel/PVDF composite coating is used to overcome the poor mechanical properties of PZT aerogels. • SiO 2 aerogels and PZT ceramic powders improve the ferroelectric and piezoelectric properties of the composite coating. • The 50-layer composite coating realizes light structure, excellent mechanical and integrated electrical properties. • The 50-layer composite coating shows extremely superior practical significance for UATs. [ABSTRACT FROM AUTHOR]