School of Chemistry - Research Publications

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    The use of ultrasonic cleaning for ultrafiltration membranes in the dairy industry
    Muthukumaran, S ; Yang, K ; Seuren, A ; Kentish, S ; Ashokkumar, M ; Stevens, GW ; Grieser, F (ELSEVIER SCIENCE BV, 2004-10)
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    Determination of the size distribution of sonoluminescence bubbles in a pulsed acoustic field
    Lee, J ; Ashokkumar, M ; Kentish, S ; Grieser, F (AMER CHEMICAL SOC, 2005-12-07)
    A simple method is described for determining the size of sonoluminescence bubbles generated by acoustic cavitation. The change in the intensity of sonoluminescence, from 4 ms pulses of 515 kHz ultrasound, as a function of the "off" time between acoustic pulses, is the basis of the method. The bubble size determined in water was in the range of 2.8-3.7 mum.
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    Sonochemical synthesis of graphene oxide supported Pt-Pd alloy nanocrystals as efficient electrocatalysts for methanol oxidation
    Neppolian, B ; Saez, V ; Gonzalez-Garcia, J ; Grieser, F ; Gomez, R ; Ashokkumar, M (SPRINGER, 2014-11)
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    The mechanism of sonochemical degradation of a cationic surfactant in aqueous solution
    Singla, R ; Grieser, F ; Ashokkumar, M (ELSEVIER, 2011-03)
    The sonochemical degradation of the cationic surfactant, laurylpyridinium chloride (LPC), in water was studied at concentrations of 0.1-0.6 mM, all below its critical micelle concentration (15 mM). It has been found that the initial step in the degradation of LPC occurs primarily by a pyrolysis pathway. Chemical analysis of sonicated solutions by gas chromatography, electrospray mass spectrometry, and high performance liquid chromatography reveals that a broad range of decomposition products, hydrocarbon gases and water-soluble species, are produced. Propionamide and acetamide were identified as two of the degradation intermediates and probably formed as the result of the opening of the pyridinium ring following OH radical addition. Most of the LPC is eventually converted into carboxylic acids. The complete mineralization of these carboxylic acids by sonolysis is however a comparatively slow process due to the hydrophilic nature of these low molecular weight products.