DEVELOPMENT OF NATURAL ADJUVANTS FOR THE FORMULATION OF SUSTAINABLE DETERGENTS

The aim of this thesis was to develop innovative and eco-friendly antimicrobial systems using natural, biodegradable, or renewable ingredients, with the dual objective of enhancing infection control and minimizing the environmental impact of industrial formulations. To achieve this, nanotechnology-based strategies were investigated, specifically focusing on the use of nanobubbles and nanodroplets as delivery systems for antimicrobial agents. This research was conducted within the framework of collaborative projects involving two industrial partners and other Departments of the University of Turin. In the first part of the work, curcumin within chitosan-shelled nanobubbles and saturated with oxygen were developed using biodegradable and naturally derived materials for the delivery of the natural occurring antimicrobial curcumin. These systems were designed to explore potential synergistic effects and improved therapeutic performance through the application of innovative technologies as the application of Photodynamic Inactivation and the co-delivery of oxygen. The results suggest that such formulations could contribute to addressing the global challenge of antibiotic resistance, by reducing the need for conventional antibiotics through enhanced antimicrobial efficacy. In the second part of the study, benzalkonium chloride-loaded nanodroplets were formulated as spray disinfectants for household cleaning. The nanodroplets were prepared using green components, including 1% limonene, to boost antimicrobial activity and simultaneously lower the required concentration of benzalkonium chloride—an ingredient currently under scrutiny due to its potential toxicity. The benzalkonium chloride-loaded nanodroplets demonstrated superior antimicrobial properties compared to BKC in aqueous solution, supporting their application as sustainable alternatives in the field of surface disinfection. The efficiency of benzalkonium chloride-loaded nanodroplets was also evaluated from a physicochemical perspective, demonstrating that the resulting spray disinfectants exhibited high wettability, wide spray angles, and long-term stability upon storage. Finally, in the last part of the thesis crude glycerol as a by-product from the Biodiesel production was transformed to other value-added products aligns with the European circular economy objectives, which aim to minimize waste and optimize resource utilization. Glycerol and glycerol formal monoglycerides, diglycerides, and triglycerides were synthesized through reactions with various fatty acids to obtain interesting materials employed for the vehiculation of essential oils and personal care.