Ambiently Dried Aerogel-Foam Composites with Gradient Pore Structure for Enhanced Sound Absorption

Area of Science:

• Materials Science
• Acoustics
• Nanotechnology

Background:

• Silica aerogels show potential for sound absorption but have limitations due to pore size and surface hardness.
• Melamine foam (MF) is a lightweight material but requires enhancement for acoustic applications.

Purpose of the Study:

• To create a gradient aerogel composite acoustic absorber using melamine foam as a scaffold.
• To improve the sound absorption performance of aerogel-based materials.
• To investigate the impact of gradient pore structure on acoustic and thermal properties.

Main Methods:

• Fabrication of gradient aerogel composite by combining silica aerogel with melamine foam.
• Characterization of density, density gradient, and sound absorption coefficients.
• Computational simulations to analyze pore size effects on sound absorption.
• Evaluation of mechanical and thermal insulation properties.

Main Results:

• Achieved low average density (31.3-117.4 mg/cm³) and a significant density gradient.
• Reached an average sound absorption coefficient of 87% across frequencies and 95% above 2000 Hz.
• Demonstrated a noise reduction coefficient of 0.59.
• Simulations confirmed the role of gradient pore sizes in enhancing sound dissipation.
• Enhanced mechanical strength and thermal insulation performance of the composite.

Conclusions:

• The gradient aerogel composite effectively overcomes limitations of traditional aerogels for sound absorption.
• The designed material offers a novel approach for advanced acoustic and thermal insulation applications.
• This gradient strategy broadens the utility of aerogels in material science.