The effect of solution level on calorific and dosimetric results in a 70 kHz tower type sonochemical reactor

237

137

Please cite this article as: R.J. Wood, J. Lee, M.J. Bussemaker, A parametric review of sonochemistry: control and augmentation of sonochemical activity in aqueous solutions, Ultrasonics Sonochemistry (2017), doi: http:// dx.doi.org/10. 1016/j.ultsonch.2017.03.030 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.A parametric review of sonochemistry: control and augmentation of sonochemical activity in aqueous solutions

Section: Liquid Heightmentioning

confidence: 99%

A parametric review of sonochemistry: Control and augmentation of sonochemical activity in aqueous solutions

Wood

Lee

Bussemaker

2017

237

137

“…The dosimetric characterization of ultrasonic bath SK5210HP (53 kHz, 100 W) followed the methodology referred by other authors [27,28]. The hydroxyl radicals produced by cavitation were quantified by conversion of terephthalic acid to 2-hydroxyterephthalic acid [27]. Solutions of 0.3 mM terephthalic acid (TA) were prepared in 0.1 M sodium phosphate buffer (pH 7.4) and submitted to cavitation during 1 h at 60°C.…”

Section: Characterization Of Sonochemical Cavitation Reactor 221 Dmentioning

confidence: 99%

“…The calorimetric characterization of the ultrasonic bath was based on the energy measurement during time for several power inputs as it was published previously by other workers [27,30,31]. The measurements were performed using a Pico Technology TC-08 Analogue to Digital converter connected to a computer.…”

Section: Calorimetric Characterizationmentioning

confidence: 99%

Ultrasound-assisted lipase catalyzed hydrolysis of aspirin methyl ester

Chiplunkar

Xin

Tomke

et al. 2018

The ultrasound-assisted hydrolysis of aspirin methyl ester (AME) was investigated using immobilized Candida antarctica lipase B (CALB) (1%) in the presence of solvents like triolein, chloroform (CHCl) and dichloromethane (DCM). The effect of ultrasound and the role of water on the conversion rates have also been investigated. Proton nuclear magnetic resonance spectroscopic (H NMR) was chosen to calculate hydrolysis convertion rates. We observed that lipase-ultrasound assisted hydrolysis of AME in the presence of triolein and water showed the highest hydrolysis conversion rate (65.3%). Herein low water amount played an important role as a nucleophile being crucial for the hydrolysis yields obtained. Lipase activity was affected by the conjugated action of ultrasound and solvents (35.75% of decrease), however not disturbing its hydrolytic efficiency. It was demonstrated that lipase is able to hydrolyse AME to methyl 2-hydroxy benzoate (methyl salicylate), which applications include fragrance agents in food, beverages and cosmetics, or analgesic agent in liniments.

“…During the process, TA scavenges Å OH to form HTA [27,[35][36][37][38]. Sonication of the 2 mM TA solution at pH 7.4 following the method of Mason et al [27] was carried out under different calorimetric acoustic powers and initial solution temperatures.…”

Section: Dosimetrymentioning

confidence: 99%

Designing and characterizing a multi-stepped ultrasonic horn for enhanced sonochemical performance

Wei

Kosterman²,

Xiao

et al. 2015

The commonly used ultrasonic horn generates localized cavitation below its converging tip resulting in a dense bubble cloud near the tip and limiting diffusion of reactive components into the bubble cloud or reactive radicals out of the bubble cloud. To improve contact between reactive components, a novel ultrasonic horn design was developed based on the principles of the dynamic wave equation. The horn, driven at 20 kHz, has a multi-stepped design with a cone-shaped tip increasing the energy-emitting surface areas and creating multiple reactive zones. Through different physical and chemical experiments, performance of the horn was compared to a typical horn driven at 20 kHz. Hydrophone measurements showed high acoustic pressure areas around the horn neck and tip. Sonochemiluminescence experiments verified multiple cavitation zones consistent with hydrophone readings. Calorimetry and dosimetry results demonstrated a higher energy efficiency (31.3%) and a larger hydroxyl radical formation rate constant (0.36 μM min(-1)) compared to typical horns. In addition, the new horn degraded naphthalene faster than the typical horn tested. The characterization results demonstrate that the multi-stepped horn configuration has the potential to improve the performance of ultrasound as an advanced oxidation technology by increasing the cavitation zone in the solution.