Core–Shell Droplet Generation Device Using a Flexural Bolt-Clamped Langevin-Type Ultrasonic Transducer

Kentaro Omori,Takefumi Kanda,Norihisa Seno,Nozomu Fujimoto,Shuichi Wakimoto

doi:10.3390/act10030055

Abstract

Droplets with a core–shell structure formed from two immiscible liquids are used in various industrial field owing to their useful physical and chemical characteristics. Efficient generation of uniform core–shell droplets plays an important role in terms of productivity. In this study, monodisperse core-shell droplets were efficiently generated using a flexural bolt-clamped Langevin-type transducer and two micropore plates. Water and silicone oil were used as core and shell phases, respectively, to form core–shell droplets in air. When the applied pressure of the core phase, the applied pressure of the shell phase, and the vibration velocity in the micropore were 200 kPa, 150 kPa, and 8.2 mm/s, respectively, the average diameter and coefficient of variation of the droplets were 207.7 μm and 1.6%, respectively. A production rate of 29,000 core–shell droplets per second was achieved. This result shows that the developed device is effective for generating monodisperse core–shell droplets.

Highlights

Droplets with core–shell structures formed from two immiscible liquids have useful physical and chemical characteristics, such as protection of the core phase by the shell phase, simultaneous use of two substances, and improved shell phase reactivity using the core phase as a catalyst
The results show that the device oscillated under a first-order flexural let generation device and vibration velocity when the driving frequency and thevibration voltage mode.29 kHz and 100 Vp-p, respectively
The results show that the device oscillated under a first-order flexural vibration was 29 kHz

Summary

Introduction

A production rate of 29,000 core–shell droplets per second was achieved. This result shows that the developed device is effective for generating monodisperse core–shell droplets. A large number of core–shell droplets can be simultaneously generated by membrane emulsification [6]. The droplets are generated individually in the microchannel, achieving a production rate of thousands of droplets per second. An efficient core–shell droplet generation method is required

Methods

Results

Conclusion