Structural diversity and properties of bio-based surfactants with their potential applications

The increasing environmental challenges associated with industrialization have intensified concerns about pollution, particularly in the chemical surfactant industry. Conventional surfactants that are largely derived from petrochemical resources pose ecological and sustainability issues, necessitating the development of renewable, less toxic, and biodegradable alternatives. Thereby, this review provides a comprehensive analysis of the structural diversity of various renewable bio-based surfactants, examining their physicochemical properties, and underlying their potential applications with performance mechanisms. The findings demonstrated that renewable bio-based surfactants exhibit significant performances, particularly in enhancing wettability alteration and reducing surface and interfacial tension, with low critical micelle concentration (CMC) at minimal dosages for improved oil recovery-achieving more than 60 % of the original oil in place (OOIP). They also demonstrate favorable viscosity and rheological properties for drug delivery and coating applications, as well as effective emulsification, foaming, and anti-foaming behavior for sustainable cleaning and food industry applications. The diversity of renewable bio-based surfactant structures is accredited by the length of the oil-loving part (hydrophobic tail) mainly derived from oil and fat, and the nature of the water-attracting part (hydrophilic head) primarily derived from carbohydrates and proteins, which guarantee the patentability in wide practical applications, and promising renewability of bio-based surfactants as an alternate to conventional petrochemical-based surfactants. Our review findings consolidate the hypothesis that renewable bio-based surfactants represent more viable alternatives to petrochemical counterparts across various applications-particularly in sustainable cleaning, drug delivery, food processing, and as environmentally friendly substitutes for conventional alkali-surfactant-polymer (ASP) systems in enhanced oil recovery (EOR).