Lightweight and mechanically robust PVA/GO composite aerogels with synergistic broadband sound absorption

Lightweight polyvinyl alcohol (PVA) aerogels with two matrix concentrations (P 5 and P 7.5 ) and their graphene oxide (GO) reinforced composites at different filler loadings (P x G 1 , P x G 2 , and P x G 3 ) were prepared via freeze-casting method, combining physical cross-linking through freeze–thaw cycling with subsequent freeze-drying at a constant thickness of 7 mm. The characterization of prepared aerogels was determined using FE-SEM, XRD, FTIR, and Raman tests. The results reveal a strong coupling between PVA matrix concentration and GO incorporation, leading to a non-linear modulation of density and porosity. Compressive stress–strain analysis demonstrates that mechanical performance is governed by a synergistic interplay between the polymer network stiffness and GO-induced reinforcement, with optimal strength achieved at higher matrix concentration and GO loading. Acoustically, the P 7.5 G x composites exhibit broadband sound absorption spanning medium to high frequencies, whereas the P 5 G x counterparts are primarily effective at high frequencies. Among all samples, the P 7.5 G 1 composite achieved the highest noise reduction coefficient (NRC = 0.36) and sound absorption average (SAA = 0.34), highlighting the role of balanced matrix–filler synergy rather than filler content alone. These findings demonstrate that controlled matrix–filler interactions enable the design of thin, lightweight, mechanically robust, and efficient broadband sound absorption PVA/GO composite aerogels. • Lightweight PVA/GO aerogels with tunable matrix and filler contents were developed. • Synergistic PVA–GO coupling enhances compressive strength and broadband sound absorption. • P 7.5 G x composites showed broader sound absorption; P 5 G x were effective mainly at high frequencies. • P 7.5 G 1 achieved the best acoustic performance (NRC = 0.36, SAA = 0.34).