2007 Fiscal Year Final Research Report Summary
Research on the establishment of high efficient sonochemical reaction field by control of the dynamics of ultrasonic cavitation bubbles
| Project/Area Number |
18560051
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied physics, general
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| Research Institution | National Institute of Advanced Industrial Science and Technology |
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Principal Investigator |
TUZIUTI Toru National Institute of Advanced Industrial Science and Technology, AIST, Senior Researcher (70357515)
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| Project Period (FY) |
2006 – 2007
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| Keywords | ultrasound / caviation bubble / sonochemical reaction / sonochemiluminescence (SCL) / pulsing operation / liquid height / liquid flow / dissolved gas concentration |
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| Research Abstract |
The enhancement of sonochemical-reaction efficiency by pulsed ultrasound at 152 kHz has been studied experimentally through absorbance measurements of triiodide ions from sonochemical oxidation of potassium iodide at different liquid volume to determine sonochemical efficiency defined by reacted molecules per input ultrasonic energy. The mechanism for enhancement of the reaction efficiency by pulsed ultrasound is discussed using captured images of sonochemiluminescence(SCL), and measured time-resolved signals of the SCL pulses and pressure amplitudes. The high sonochemical-reaction efficiency by pulsed ultrasound, compared with that by continuous-wave ultrasound, is attributed both to the residual pressure amplitude during the pulse-off time, and to the spatial enlargement of active reaction sites.
Sonochemical reaction rate is enhanced by the addition of tiny bubbles and liquid flow, and the operation under the reduced amount of dissolved gas is more effective especially at the bubble addition. It has been found that it is important to adjust the configuration of tiny-bubble addition to the sound field. Through the investigations on the intensity and the spatial pattern of luminol-sonochemiluminescence, it has been clarified that tiny bubbles added into the sonicated liquid directly connect to an increase in the number of collapsing bubbles active for sonochemical reaction.
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