Alkyl polyglycosides derived from α-olefins via Fisher glycosidation and their adsorption and aggregation behavior in aqueous solution

The effective and stable use of α-olefins is a topic of great research interest due to their abundant reserves, and the fact that the hydrolysis and epoxidation reaction of these substances produces hydroxyl group as a key linking group plays an important role in the synthesis of surfactants. Consequently, a series of alkyl polyglycosides (DC 08 PG, DC 10 PG, and DC 12 PG) were synthesized as non-ionic surfactants via the glycosidation reaction of long-chain 1, 2-vicinal diol with different carbon numbers and glucose. The results showed that 1, 2-vicinal diol exhibited increased reactivity in glycosidation due to their unique molecular structure. Furthermore, it was observed that the degree of polymerization (DP) achieved was notably elevated, registering at 1.63, surpassing the DP of 1.37 typically prepared using conventional methods. This enhancement was paralleled by a demonstrable increase in hydrophilicity, as evidenced by the hydrophile-lipophile balance number (HLB), resulting in a substantial improvement in the water solubility of the product, the transmission rate > 90 %. For adsorption and aggregation behavior, DC 12 PG showed a smaller cross-sectional area ( A min ), larger saturation adsorption ( Γ max ), and could aggregate to form micelles at low concentrations, and short-term dynamic adsorption properties (DST) was prominent. At the same concentration, for foam properties, DC 12 PG with longer alkyl chains produced higher and more stable foam; for emulsification properties, the emulsification time was 298 s; for wetting properties, the contact angle was 61.59° in 30 s. This analysis will help to reveal the intrinsic connection between the molecular structure and properties of surfactants.