Waste-free synthesis of silica nanospheres and silica nanocoatings from recycled ethanol-ammonium solution.

In this study, ethanol-ammonium recovery using a distillation system was evaluated. The experimental design was used to evaluate the possibility of solvent re-use and the influence of distillation on the recovery yield, ethanol-ammonium ratio (catalyst concentration) and size of the obtained nanostructures. The synthesised silica nanospheres from distilled ethanol-ammonium were compared in terms of size and shape (ammonium concentration) to the nanostructures obtained from filtrated and centrifuged solvents. The results showed that the process for ethanol-ammonium recovery proposed in this work, provides a large potential for reducing the amount of waste from the synthesis. [ABSTRACT FROM AUTHOR]