Abstract
This study reports the aggregation behavior of polylactic acid (PLA) with ionic surfactants e.g. sodium dodecyl sulphate (SDS) and hexadecyltrimethylammonium bromide (CTAB) at different temperatures. Surface tension and conductivity techniques were used to investigate these physicochemical properties. Surface tension measurements were carried out to find out critical micelle concentration (CMC), free energy change of micellization (Δ
), free energy change of adsorption (Δ
) and surface excess concentration (Γ). Conductivity measurements were used to determine CMC, degree of ionization (
) and degree of counter ion binding (
). The values of
and
obtained for SDS were (0.389 and 0.611 respectively), while for CTAB the values of
and
were (0.239 and 0.761 respectively). This type of electrostatic interactions is very important which can be applied in various industrial applications (e.g. pharmaceutical, industrial foaming, oil recovery etc.).