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HIGH RESOLUTION ULTRASOUND SPECTROSCOPY IN HUMIC RESEARCH Miloslav Pekař Jiří Kučerík Daniela Šmejkalová Martina Klučáková Institute of Physical and Applied Chemistry Faculty of Chemistry Brno University of Technology Brno, Czech Republic
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? ULTRASOUND SPECTROSCOPY ? TRADITIONAL SPECTROSCOPY sample electromagnetic wave ULTRASOUND SPECTROSCOPY ultrasound wave (mechanical)
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ULTRASOUND INTERACTION WITH MATTER intermolecular forces probe microelasticity
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ULTRASOUND FREQUENCY
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ULTRASOUND PARAMETERS velocity... amplitude (attenuation)......... elasticity, density...... energy loss
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ULTRASOUND VELOCITY elastic response dominating sensitive to molecular organization, intermolecular interactions v solids liquids gases rigidity ... velocity
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ULTRASOUND ATTENUATION heterogeneous sample scattering particle sizing homogeneous sample local relaxation
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HIGH RESOLUTION RESOLUTION high normal ATTENUATION VELOCITY 0.1 m/s 0.0001 m/s (10 -5 %) 0.2%
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EXAMPLE – MICELLES hydrophobic core... higher elasticity
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EXAMPLE – CONFORMATION CHANGES temperature ramp - polyacrylamide
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EXAMPLE – LIGAND BINDING Mg 2+ to polyriboadenilic acid
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EXAMPLE – AGGREGATION carbonic anhydrase, temperature induced
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EXAMPLE – MICROEMULSION lipid+surfactant+cosurfactant and water
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QUANTITATIVE INTERPRETATION – PRINCIPLES velocity of sound sound – longitudinal wave causes local variation of the density, pressure finite compressibility energy transports across the space compressibility
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QUANTITATIVE INTERPRETATION – DECOMPOSITION DILUTE SOLUTIONS (adiabatic) apparent molar volume apparent molar compressibility solution solute solvent M …solute h …hydration r …relaxation contributions
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QUANTITATIVE INTERPRETATION – CONCLUSION concentration increment of ultrasound velocity K M … constant K r … from frequency dependence of attenuation K h … evaluated solution solvent molality
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NaHu - CONCENTRATION
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NaHu + ACID … KINETICS 0.5g/L NaHu pH: 7 3.5
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NaHu + ACID … VELOCITY NaHu concentration (g/L) velocity change (m/s) HCl
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NaHu + ACID … VELOCITY NaHu concentration (g/L) velocity change (m/s) propionic
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NaHu + PROPANOL … VELOCITY NaHu concentration (g/L) velocity change (m/s) propanol
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Cu 2+ + SALYCILIC ACID velocity (m/sec) time (sec) blank sample
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THANKS … … for your attention
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