Influence of Silica Sols and Magnetic Nanopowders of Iron Oxides on Barkley Seeds during Their Interaction with Water

The surface modification of barley seeds with micro additives of silica sol based on hydrolyzed tetraethoxysilane containing various amounts (0.001–10 000 mg/L) of maghemite (γ-Fe 2 O 3 )–magnetite (Fe 3 O 4 ) magnetic nanoparticles affects the interaction between the seeds and aqueous medium. The increase in seed weight (water absorption) depends nonlinearly on the amount of added γ-Fe 2 O 3 –Fe 3 O 4 (the maximum increase being observed at its content of about 0.1 mg/L in the silica sol), which contributes to a more pronounced trend towards better seed germination. Furthermore, the seeds are found to have a stabilizing (buffer) effect on the acid–base properties of the aqueous medium within 5 min after they were dipped into water: they cause a certain increase in water pH in the case when the initial pH is < 7 and a decrease in water pH when the initial pH is > 7.