Effects of length and type of the alkyl chain on the micellization behavior of mixed systems of HS15 with fatty acids

Abstract

Due to volatility, low solubility and instability, the application of SCFAs and MCFAs is limited, which is expected to be solved by micelles. Taking SCFAs and MCFAs as models, this paper aims to research the influences of alkyl chain length and type on HS15 micelles. The critical micelle concentration (CMC) of various acid-HS15 systems was determined firstly. Then some air-water interface parameters and thermodynamic parameters were analyzed. Subsequently, particle size, cloud points (CP) and fluorophore release curves were measured. With the increase of CMC and G_min, the decrease of size and CP, and the rapid quenching of fluorophores, it is more difficult for acids with longer-chain to form stable micelles with HS15 because of the strength of iceberg structure. Showing smaller CMC and G_min, smaller size, higher CP and slower release of fluorescers, branched molecules can bind more closely to the hydrophobic part of HS15 due to their spatial flexibility.

Keywords: Critical micelle concentration; HS15; Medium-chain fatty acids; Micellization behavior; Short-chain fatty acids; Thermodynamic stability.