Maltodextrin–SDS interactions: Volumetric, viscometric and surface tension study

Abstract

Carbohydrate–surfactant interactions and micellization behavior of anionic surfactant (sodium dodecyl sulfate, SDS) in aqueous solution of (0, 0.5, 1.0 and 1.5%w/v) maltodextrin have been studied using density, sound velocity, viscosity and surface tension in the temperature range of 20–40°C at an interval of 5°C. Density and speed of sound data have been used to derive parameters like isentropic compressibility (κs), apparent molar volume (Φv) and apparent molar isentropic compression (Φk). Surface tension has been used to calculate surface excess concentration (τmax), minimum area occupied by the surfactant (Amin) and surface film pressure (πcmc) whereas relaxation time (τ) is calculated using viscosity data. Volumetric measurements indicate that Φv values are positive and generally increase with rise in temperature as well as with increase in percentage of maltodextrin (0.5–1.5%). Viscous relaxation time (τ) and surface tension (γ) have been found to decrease with rise in temperature.