Advanced aerogels from waste tires and coal ash for thermal and acoustic insulation applications- insights into the effect of synthesis conditions and precursors contents on aerogel characteristics

Over the years, as the economy has grown, numerous new materials have been developed to replace traditional ones. Among these materials, aerogels have become a topic of intensive research. However, the growth of the economy has also had negative impacts on the natural environment, particularly in industries like automotive and energy, which generate a significant amount of waste tire and coal ash. To address these problems, our research has been focused on synthesizing an advanced aerogel using waste tire rubber powder (WTRP) and coal ash (CA), which not only helps to solve the dual problems of the environment but also produces a green material with high applicability. The resulting aerogel has an ultra-low density (0.055 g/cm3) and high porosity (95.6%), making it an excellent insulator with a thermal conductivity of 0.027 W/m.K. Additionally, the aerogel exhibits significantly enhanced rigidity, with a Young modulus of Eavg = 1.206 MPa. Furthermore, the composite aerogel also possesses a good noise reduction coefficient (NRC) of 0.414. The exceptional properties of the aerogel suggest that it holds great promise as a new generation of sustainable, effective, and low-cost materials for thermal and sound insulation.