No. of

synthesis

Activation

Solution No.

Alkalinity/Acidity

Synthesis

T, ˚C

t, min

1

(H₂O:NaOH)

2

(H₂O:C₆H₈O₇)

3

(H₂O:NaOH)

T, ˚C

t, days

1

85

15

1.8

5.9

4.0

85

3

2

60

15

1.8

4.8

4.0

60

7

3

60

15

1.8

5.9

4.2

60

6