https://www.selleckchem.com/
A material's acoustic properties depend critically upon porosity. Doping a soft material with gas-filled microballoons permits a controlled variation of the porosity through a scalable fabrication process while generating well-tailored spherical cavities that are impermeable to liquids. However, evidence is lacking of how the nanometer-scale polymeric shell contributes to the overall effective material properties in the regime when the wavelength is comparable to the sample thickness. Here we measure ultrasound transmission through a microballoon-doped soft