Wormlike micelles in green surfactant systems

Sammanfattning

α-Olefin Sulfonate surfactants offer a greener alternative to traditional sulphated surfactants thanks to their higher biodegradability. Their similar molecular structures should, in theory, allow them to be used in the same range of applications as the sulphonated counterpart. However, the newer alternative also comes with novel challenges. While the thickening of a formulation with a sulphated surfactant can be achieved by salt addition, novel sulphonated surfactants require the introducing co-surfactants to the formulation. Previous studies at CR resulted in the design of a purification process that enhanced the viscosity build up capacity of the surfactant was achieved. In this master thesis work this method was applied and tested. Through techniques such as HPLC-MS and NMR the content of the surfactant was unveiled, revealing that the technical grade surfactant was a mixture of different compounds. Among them, the most possible culprit for hindering the thickening capacities those holding an alcohol group in carbons distancing from the head group. Additionally, the surfactant-water system was further characterized utilizing SAXS and DLS, leading to the elaboration of a phase diagram. The acquired knowledge will help formulators incorporate the greener alternative in their products, and guide manufacturers on how to make a surfactant with enhanced properties.