The interactions of dextran with surfactant SDS

abstract

English

Dextran is a homopolysaccharide made of many glucose molecules, produced by enzymatic conversion to sucrose as a bacterial product [1]. Because of positive charged dextran hydrochloride (DEAE) and negative charged sodium dodecyl sulphate (SDS), we can measure interactions between them. Added surfactant reacts with hydrophobic groups of the homopolysaccharide which leads to micelles formation. Micelles can be determined using high resolution ultrasonic spectroscopy (HR-US) which employs sound waves during the measurement. Before characterization of interactions between DEAE and surfactant SDS, properties of DEAE solutions of various concentrations in different solvents (water and 0.15 mmol/l NaCl) were investigated. The ultrasonic velocity was measured by HR-US in a kinetic mode at 25 °C. The ultrasonic velocity increases linearly with the increasing concentration of DEAE. Subsequently, interactions of DEAE with SDS were examined to determine the critical aggregation and critical micelle concentration using HR-US in a titration mode at 25 °C. At first, titration was performed with SDS in water and 0.15 mmol/l NaCl. The velocity increases with increasing surfactant concentration and the point of abrupt change of the slope determines CMC. CMC of water was determined as 9.5 mmol/l and CMC of 0.15 mmol/l NaCl as 1.6 mmol/l.

Dextran, SDS, high resolution ultrasonic sepctroscopy

KOLENOVÁ, M.; KARGEROVÁ, A.

5. 10. 2018

Brno University of Technology, Faculty of Chemistry

Brno

35

36

72

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