Controllable self-assemblies of sodium benzoate in different solvent environments

Abstract

Sodium benzoate is an important and widely used food additive, however, its self-assembly properties in diverse solvents have been rarely studied. Here, we report different self-assembled aggregates, including sodium benzoate vesicles and sodium benzoate gel, in different solvent environments. Sodium benzoate vesicles and gel were identified by Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM) and Dynamic Light Scattering (DLS). Ultraviolet-visible (UV-vis) spectroscopy, Fourier Transform Infrared (FT-IR) spectroscopy, Thermal Gravity Analysis (TGA), Differential Scanning Calorimetry (DSC) and Small-Angle X-ray Scattering (SAXS) were further employed to study the formation mechanism of the sodium benzoate gel. A possible gel formation mechanism was proposed. Furthermore, sodium benzoate gel has multiple stimulus responsiveness, the addition of hydrochloric acid and metal ions can all cause disaggregation of sodium benzoate gel. Finally, sodium benzoate aggregates were found in calf serum.