Nanocomposite formulations of titanium dioxide and algal biomass: A rheological characterization for topical cosmetics and dermal applications

Abstract

This study investigates rheological properties of novel, algae-based nanocomposites developed for potential use in dermal applications. The purpose of this investigation is to develop a highly tunable, biocompatible cosmetic base formulation and demonstrate how rheology relates to spreadability in its application. It was hypothesized that Spirulina biomass could be used in conjunction with titania (TiO2) nanoparticles and crosslinking and binding agents of calcium and/or citric acid to form nanocomposite materials with highly tunable rheological characteristics in absence of chemical surfactants. In this study, Arthrospira platensis (Spirulina) biomass, titanium (IV) dioxide, calcium chloride, and citric acid are used to develop a formulation that is then tested for a wide range of rheological characteristics and sensory-related properties. The rheological tests include amplitude sweep, frequency sweep, viscosity flow curve, 3-interval strain oscillatory thixotropy, and creep – recovery. Additionally, yield stress, complex viscosity, zero-shear viscosity, and power law indices were determined. The sensory-related properties that are discussed include formulation pH, static load spreadability, and dynamic shearing spreadability. After completing the investigation, it was concluded that the surfactant-free formulations were highly tunable, in terms of viscosity, rigidity, and thixotropy.