Stability and application of TiO₂ nanomaterials in aqueous suspensions: a review

Excellent photo-physical, photo-chemical, and surface properties, which enable them to be used in a wide range of applications, make TiO₂ nanomaterials (TiNMs) among the most extensively investigated and commercially utilized nanomaterials. In many applications, TiNMs are used in the form of suspensions. Therefore, understanding their dispersibility and colloidal stability is crucial. Despite a large number of investigations into the colloidal stability of TiNMs, the preparation of stable suspensions and the choice of suitable dispersants still rely on trial and error. Motivated by this, in this review, we present and discuss the versatility of dispersants for stabilizing TiNMs. The investigations are discussed within the framework of DLVO theory, which, despite its limitations, provides a theoretical foundation for understanding the observed effects. In addition, tested and commercial applications are briefly discussed.