Preparation and Properties of Gemini Glycosyl Organosilicon Quaternary Ammonium Salts with Excellent Sustained Foam-Associated Antibacterial Activity

In this study, d-glucono delta-lactone was used as the raw material to sequentially conduct amidation, substitution, and quaternization reactions, through which a novel Gemini sugar-based amide organosilicon quaternary ammonium salt surfactant (2/3SiDDGMAPB) was designed and synthesized, and its molecular structures were confirmed by FT-IR and nuclear magnetic resonance. Notably, the results of physicochemical characterization and application performance investigation demonstrate that the surface tension of 2SiDDGMAPB is as low as 29.38 mN/m. Transmission electron microscopy, energy-dispersive spectroscopy, and dynamic light scattering characterizations reveal that 2SiDDGMAPB forms uniformly spherical micelles. The system exhibits robust foaming and foam-stabilizing performance across various water qualities and outstanding short-term foam stability in practical aqueous systems. Notably, both compounds display ultrahigh antibacterial activity against Staphylococcus aureus and Escherichia coli (with MIC as low as 0.001%), maintaining a 100% antibacterial rate even after 35 washing cycles. Toxicity tests in mice and skin irritation tests in rabbits confirm that 3SiDDGMAPB is practically nontoxic (LD50 > 5000 mg/kg) and nonirritating. 2/3SiDDGMAPB is a multifunctional surfactant combining rich foaming performance, long-acting bacteriostasis, and high biosafety, with excellent application potential and broad market prospects.