Colloidal Silica




Colloidal silicas are most often prepared in a multi-step process where an alkali-silicate solution is partially neutralized, leading to the formation of silica nuclei. The subunits of colloidal silica particles are typically in the range of 1 to 5 nm. Whether or not these subunits are joined together depends on the conditions of polymerization.

 

Initial acidification of a water-glass (sodium silicate) solution yields Si(OH)4. If the pH is reduced below 7 or if salt is added, then the units tend to fuse together in chains. These products are often called silica gels. If the pH is kept slightly on the alkaline side of neutral, then the subunits stay separated, and they gradually grow.

Colloidal Silica Sol :

Products :

ZCS- 30
ZCS-40
ZCS-20 ACIDIC
ZCS30 ACIDIC
ZCS-30 NEUTRAL
ZCS-30 SM
ZCS-40 SM
ZCS- 15 AS
ZCS-30 AS
ZCS 500/SM
ZSC 400



Specifications

 

Grade

SiO2%

pH

Titrable Alkali(w/w)

Specific Gravity
at 250C

Specific Surface Area(m2/g)

Mean Particle Size(mµ)

Viscocity
Cps at 270C

 

ZCS-30

30

9.75

0.35-0.4

1.2

220-300

12-9

3-4

 

ZCS-40

40

9.72

0.31

1.3

160

17

3.2-4

 

ZCS-20 ACIDIC

20

4-4.6

-----

1.155

160

17

3.05

 

ZCS-30 ACIDIC

30

4-4.6

------

1.2

160

17

4

 

ZCS- 30 NEUTRAL

30

8

-------

1.204

220

12

3.85

 

ZCS-30 SM

28.5

8

-------

1.193

340

8

3.9

 

ZCS-40 SM

40

8

-------

1.303

220

12

7

 

ZCS-15 AS

15

220

-------

1.097

220

12

1.55

 

ZCS-30 AS

30

8.68

-------

1.205

220

12.4

3.75

 

ZCS 500/SM

15

10.4

0.45

1.1

500

5.45

1.79

 

ZCS- 400

30

10.5

0.45

1.2

400-450

6.8-7

3.49