Physicochemical investigation of cellulose microbeads produced through cross-flow membrane emulsification for cosmetic applications

Microbeads have become an indispensable part of our daily lives, especially in the cosmetic industry. However, microbeads fabricated from commercial polymers are not biodegradable and have harmful environmental impacts. As one of the most abundant biopolymers, cellulose has attracted increasing attention as a biodegradable material. Hence, we investigated a facile method for fabricating cellulose microbeads via cross-flow membrane emulsification, which could facilitate high-volume production, to provide a sustainable alternative to conventional microplastics. This study successfully produced cellulose microbeads through cross-flow membrane emulsification and comprehensively analyzed their physical and chemical properties to enhance their potential for diverse applications, including the cosmetic industry. Cellulose microbeads with a median diameter of 6.97 μm were fabricated using cross-flow membrane emulsification and further modified with octadecyltriethoxysilane (ODTES) to tailor their properties for specific applications. The transformation of cellulose acetate into cellulose was achieved through deacetylation, as confirmed by comprehensive morphological and chemical analyses. The cellulose microbeads exhibited a neutral pH (close to 7) regardless of the type and demonstrated mechanical robustness with a compressive strength of 5.75 MPa for the cellulose microbeads and 8.22 MPa for the ODTES-modified cellulose microbeads. These findings demonstrate the potential of cellulose beads as an environmentally friendly alternative to plastic microbeads, aligning with global sustainability initiatives and opening new possibilities for innovation in cosmetic formulations.