Green Coacervates for Pharma and Food

Sammanfattning: Anionic biosurfactant-cationic biopolymer systems were investigated to identify and characterize a coacervation window. The characterization of the systems was performed with dynamic light scattering, small angle x-ray scattering and in-situ ellipsometry. The surfactants sodium- and potassium caprylate (NaC10, KC10) and sodium- and potassium laurate (NaC12, KC12) were studied with titration experiments, C10 had pKa 7.8 and C12 had pKa 8.6. The system needed to be above pH 9 for the surfactants to be soluble and form micelles. The studied biopolymers were QUATIN® 350 TQ-D (Q350), 680 TQ-D (Q680) and N-Hance™ CCG 45 (N-Hance), in concentration range 0.5-2 wt%. The most studied system was NaC10-Q680 2 wt%. The coacervation area mapped out for this system was within the concentrations 1-2 wt% NaC10, which is around the critical micelle concentration (CMC). This was observed regardless of Q680 concentration. Therefore, the CMC was the main factor for coacervation since micelles are required for coacervation. Systems that exhibited coacervation could do this far from charge neutrality. Hence other factors play a role in coacervation.