A surfactant-free, eco-sustainable detergent utilizing collagen Pickering emulsions

Abstract

The extensive utilization of synthetic detergents presents a substantial threat to the global environment. Inspired by traditional practices in Asia—such as using rice-washing water for cleaning—this study develops a green, non-toxic, and surfactant-free detergent. The innovative detergent was fabricated using natural collagen extracted from delimed bovine hide trimmings as the core component, requiring no chemical modification. It forms in situ Pickering emulsions on contaminated surfaces, effectively encapsulating and removing oil stains. Interfacial desorption energy measurements indicate that the collagen detergent adsorbs irreversibly at the oil–water interface (approximately 2.2 × 10⁷ K_BT). The collagen detergent achieves a comparable cleaning efficiency of up to 90% on both human skin and various material surfaces, in comparison with commercial products. More importantly, it is non-irritating to the eyes and skin and exhibits no toxicity toward cells, seeds, lettuce seedlings, and zebrafish. By combining high detergency with exceptional biocompatibility and environmental safety, this approach offers a compelling alternative to conventional surfactants. Remarkably, the detergent is produced solely from delimed bovine split trimmings, demonstrating the potential of collagen valorization for next-generation sustainable cleaning agents that align with ecological preservation and public health priorities.