Zinc oxide/carbohydrate hybrid materials via mineralization of starch and cellulose in the strongly hydrated ionic liquid tetrabutylammonium hydroxide

Zinc oxide/carbohydrate hybrid materials have been fabricated via mineralization of ZnO in the strongly hydrated ionic liquid (IL) tetrabutylammonium hydroxide (TBAH) in the presence of cellulose or starch. TBAH dissolves the ZnO precursor zinc acetate; it also reacts with zinc acetate to form ZnO nanoparticles. Tetrabutylammonium acetate forms as a side product and further acts as a template for nanoparticle formation. X-ray diffraction reveals that the primary building blocks have a rod- or needle-like shape (i.e., the coherence length along the crystallographic c-axis is larger than along the crystallographic a-axis), which is unusual for ZnO grown from solution in the presence of organic additives. In the presence of starch, organic/inorganic hybrid sponges form. The mineralization of cellulose is less effective due to its lower solubility in TBAH, but the results suggest that our process can be used to coat cellulose efficiently. Overall, TBAH acts as a solvent-reactant (an ionic liquid precursor, ILP), which leads to ZnO/carbohydrate hybrid materials where the architecture of the precipitate is controlled by the carbohydrate additive.