From the seed solution 1 ml was added to flask A and stirred for 10 s.
From the solution in flask A, 1 ml was added to flask B and stirred for 15 s.
Finally, 5 ml of the solution in flask B was added to flask C and stirred for 15 s.
The resulting solution was left overnight at 25 ◦C.
The next day, the upper part of the solution in the flask was carefully and completely removed until only the sediment at
the bottom of the flask was left.
The sediment was redispersed in 15 ml of water. The resulting particles are shown in the SEM image
in Fig. 1(right).