A simple derivation of the critical condition for the ultrasonic atomization of polymer solutions.
A simple model is proposed for the ultrasonic atomization of polymer solutions. In this model, the atomization process is approximated as an equilibrium process. It is shown that the minimum attainable droplet size is determined by two parameters, the (Rayleigh) acoustic pressure acting on the surface of the liquid, and the surface tension of the liquid. Increasing the viscosity of the liquid suppresses the formation of small-sized droplets because of increased attenuation of the sound wave and thus decreased acoustic pressure. Lowering the surface tension of the liquid (e.g., by spreading a surfactant film on the liquid surface) has the opposite effect of enhancing the formation of smaller droplets. Also, there exists a maximum limit for the droplet size, because when the produced droplet is too large, the aspiration flow is unable to carry the droplet against sedimentation. These predictions are supported by experimental observations.
Department of Chemical Engineering, Dankook University, Yongin-si, Gyunggi-do 448-701, Republic of Korea. Electronic address: hkim@dku.edu.
Hyungsu
H
Kim
Department of Chemical Engineering, Dankook University, Yongin-si, Gyunggi-do 448-701, Republic of Korea. Electronic address: jklee8813@naver.com.
Jaegeun
J
Lee
School of Chemical Engineering, Purdue University, West Lafayette, IN 47907, USA. Electronic address: yywon@ecn.purdue.edu.
You-Yeon
YY
Won
D055592:Biophysical Phenomena; D057927:Hydrophobic and Hydrophilic Interactions; D008855:Microscopy, Electron, Scanning; D008962:Models, Theoretical; D011092:Polyethylene Glycols / Q000737:chemistry*; D011142:Polyvinyl Alcohol / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry*; D013010:Sonication; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry*
D012996:Solutions; D013501:Surface-Active Agents; D011092:Polyethylene Glycols; D011142:Polyvinyl Alcohol; C043444:octadecyl polyoxyethylene ether
Acoustic pressure; Micro droplets; Polymer solution; Surface tension; Ultrasonic atomization