Titanium oxide hydrates as versatile polymer crosslinkers and molecular-hybrid formers

Molecular hybrid materials based on widely available polymers crosslinked with an inorganic species have received increasing interest for their unique property sets outside of the usual range of commodity plastics and/or nanocomposites. Here, we provide a mini-review on molecular hybrids based on metal oxide hydrates—compounds that readily react with, for example, hydroxylated polymers to form inorganic:organic materials systems with many desirable features and properties. Focusing on titanium oxide hydrates, we discuss here that such molecular hybrids can exhibit a broad refractive index range in addition to an increased glass transition temperature, mechanical stiffness and swelling resistance in comparison to the neat polymer, which illustrates that such hybrid systems offer a new, low-cost, robust and versatile functional materials platform with great promise for, for example, solution-processed photonics, catalysts and antimicrobial coatings. Generally, our mini-review seeks to provide a concise and accessible overview of titanium oxide hydrate:polymer hybrid systems, focusing on their unique properties and processability as well as their broad and largely untapped potential as functional materials. © 2024 The Author(s). Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.