Ultrasonic cavitation noise in suspensions with ethyl cellulose nanoparticles

摘要

Hydrophobic biodegradable ethyl cellulose (EC) nanoparticles are commonly used to stabilize the gas/liquid interfaces. To produce EC foams, ultrasonication with a driving frequency of 21.45kHz is utilized. EC suspension reduced the cavitation noise, and the immersing depth of the vibrating horn influenced the foamability of the EC particles. When the horn is near the air/liquid interface, dense and homogeneous EC foams will be obtained, but when the horn is near the bottom wall, sparse and polydisperse EC foams are obtained. This is attributed to the fact that more bubbles are stabilized by the EC nanoparticles in the ultrasonic field when the horn is near the air/liquid interface; therefore, the collapse of the bubbles is suppressed, and the sound pressure level is lowered on the broadband.