One-pot Synthesis of Redispersible Polymer-stabilized ZnO Nanocomposites

Nanomaterials have gained noteworthy attention in several applications due to their significantly improved properties relative to their bulk counterparts. However, achieving effective redispersibility of nanomaterials in a wide array of solvents, with inhibited particle agglomeration and preserved properties such as large surface area, remains challenging. In this study, a method of imparting both redispersibility and colloidal stability into zinc oxide (ZnO) nanoparticles was done through in situ addition of polymer stabilizers such as poly(acrylic acid) (PAA), poly(ethylene glycol) (PEG), and poly(vinylpyrrolidone) (PVP). This method enabled straightforward redispersion of as-synthesized ZnO/polymer powders into colloidal nanoparticle dispersions with smaller hydrodynamic diameter and lower zeta (ζ) potential values relative to bare ZnO. Band gap energies of resultant ZnO/polymer nanoparticles, with precise values about that of pristine ZnO (~ 3.37 eV), also correlated well with their respective efficiencies when used as a photocatalyst. Polymer-stabilization likewise preserved the high surface area of ZnO/polymer particles even in dispersions, resulting in improved photodegradation of a model pollutant [i.e. ~ three-fold increase in tartrazine (TZ) degradation for ZnO/PAA]. It is envisioned that our findings will provide critical insights on the impact of polymer stabilization on processing and prolonging the shelf life of nanoparticles while preserving their unique properties such as catalytic efficiency.