著者

大常 雄基 安田 啓司 朝倉 義幸

出版者

日本ソノケミストリー学会

雑誌

ソノケミストリー討論会講演論文集 25 (ISSN:24241512)

巻号頁・発行日

pp.39-40, 2016 (Released:2017-07-21)

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To investigate generation of ultrasonic cavitation in gel, sodium polyacrylate swollen in potassium iodide solution was used as a sample. After ultrasonic irradiation at 500 kHz, absorbance and viscosity of sample were measured. The absorbance and viscosity changes are originated from oxidation reaction of potassium iodide and decrease in the degree of polymerization of sodium polyacrylate, respectively. The absorbance started to increase after several minutes irradiation. On the other hand, viscosity decreases immediately after irradiation. This is because polymer is degraded due to shear stress of ultrasonic propagation in addition to cavitation. After sample viscosity fully decreased, it is able to generate ultrasonic cavitation and chemical reaction occurs. As sample temperature became lower, the viscosity decreased and the absorbance increased. To use this sample, detection of cavitation generation in gel is possible.

著者

竹村 洸亮 安田 啓司 朝倉 義幸

出版者

日本ソノケミストリー学会

雑誌

ソノケミストリー討論会講演論文集 (ISSN:24241512)

巻号頁・発行日

pp.41-42, 2016 (Released:2017-07-21)

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Ethanol and organic material mixed aqueous solution were atomized using ultrasonic irradiation at 2.4 MHz. Atomized liquid was collected by refrigeration of liquid nitrogen. The concentrations in collected liquid and mist were experimentally investigated. Malic acid, lactic acid (organic acid), 1-propanol, methanol (alcohol), methyl ethyl ketone, diethyl ketone (ketone) were used as organic material. The ethanol concentration in collected liquid was little affected by addition of organic materials. Organic acid in ethanol aqueous solution was not separated. On the other hand, alcohol and ketone concentrations in collected liquid were higher than those in sample. The 1-propanol concentration in collected liquid was lower than that in mist. This is because it is difficult to collect nano-sized droplets which contain highly condensed alcohol.

著者

福壽 快斗 朝倉 義幸 香田 忍

出版者

日本ソノケミストリー学会

雑誌

ソノケミストリー討論会講演要旨集

巻号頁・発行日

no.22, pp.39-40, 2013-10-25

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We have re-examined the frequency dependence of the cavitation threshold for air-saturated water and organic solvents. Cavitation threshold was estimated by observation of generation of cavitation from the results of the polymer degradation effect and acoustic spectrum. We used direct irradiation type and indirect irradiation type ultrasonic reactor in this experiment. All experiments were performed in the driving power 0.5〜50W, fluid volume 50mL, the driving frequency 20kHz〜5MHz. Cavitation threshold which is calculated from the results of the polymer degradation was larger than the cavitation threshold, which is calculated from the acoustic spectrum measurement. Regardless of solvents, in the frequency range below 45kHz, cavitation threshold decreased with increasing the frequency. Further, in the frequency range above 45kHz, cavitation threshold gradually increased with increasing the frequency.