Preparation of colloidal manganese dioxide

1. Presented By : Sagar Kumar
dutta
Student I.D- 111815

2.  The dark brown Mn-ore which have self-catalytic & oxidizing properties are
known as MnO2.
 Its application are notably limited because of it insolubility under ordinary
condition.
 It use as a detectable intermediates or reaction products in most permanganate
oxidation, so that the reaction kinetics can be determined.
 Colloidal MnO2 solution is prepared by reducing KMnO4 with a stoichiometric
amount of Na2S2O3 according to the reaction:
8MnO4
- + 3S2O3
2-+ 2H+ = 8MnO2 + 6SO4
2- + H2 O

3.  To find out the stable condition of colloidal MnO2.
 To obtain reliable condition on the stability of the colloidal in presence and
absence of cationic, anionic and nonionic surfactants.
 To improve knowledge about micellar catalytic effect on the stability of colloidal
MnO2 system.
 To reveal the optimized condition which increase the stability of colloidal
system.

4. The colloidal solutions or colloidal dispersions are intermediate
between true solutions and suspensions.
Figure : Particle size of True solution , colloidal & suspension
What is Colloidal
solution?

5.  Basically, colloidal sols are color and MnO2 solution are brown in color.
 Like as colloidal solution MnO2 also shows light scattering properties.
 Electronic properties are shown by the colloidal MnO2 because when MnO2 acts
as a catalyst in reaction it can from negative charge.
 The colloidal MnO2 has colligative properties (namely osmotic pressure,
elevation in boiling point, depression in freezing point etc.)

6. A surfactant active agent, or wetting agent, capable of reducing the surface
tension of a liquid; typically organic compounds having a hydrophilic “head”
and ananhydrobic “tail”.
What is surfactant?
Fig: The basic molecular structure of surface-active materials

7.  Cationic Surfactant:
 Anionic Surfactant:
 Non-ionic surfactant:
SDS
CTAB
TX-100
Classification of surfactants:

10. Experimental & observation
Stability
Investigation of
Colloidal MnO2
solution
Concluding
remark
Preparation of colloidal MnO
Approach-2
Approach-3
Approach-402/11/2015 03/11/2015
Mixture 0.02M KMnO4 0.02M Na2S2O3 1M HCl Volume
Of H2O
(mL)
Total
Volume
(mL)
Volum
e (mL)
Final
Conc.
(M)
Volume
(mL)
Final
Conc.
(M)
Volume
(mL)
Final
Conc.
(M)
M-1-1
5 0.005 5 0.005
0.2 0.01 9.80
20.00
M-1-2 2.0 0.10 8.00
M-1-3 4.0 0.20 6.00
M-1-4 6.0 0.30 4.00
M-1-5 8.0 0.40 2.00
 For first approach the over all mixture concentration:
Reaction: 8MnO4
- + 3S2O3
2-+ 2H+ = 8MnO2 + 6SO4
2- + H2 O

11. Experimental & observation
Preparation of colloidal MnO
Approach-1
Approach-3
Approach-4
Stability
Investigation of
Colloidal MnO2
solution
Concluding
remark
Approach-2
M-1-1 M-1-2 M-1-3 M-1-4 M-1-5 M-1-1 M-1-2 M-1-3 M-1-4
M-1-5
 Image Observation:
(a) Immediately after the reaction (b) After 24 hours.
 Under this condition the reduction process occur quickly and with in 24
hours it formed precipitated MnO2. (colloidal was not found).

12. Medicinal application of the OintmentExperimental & observation
Preparation of colloidal MnO2
Approach-3
Approach-4
(Aqueous
Condition)
Stability
Investigation of
Colloidal MnO2
solution
Concluding
remark
Approach-1
Approach-2
(Acidic Condition)
 In this time the resulting concentration of KMnO4 and Na2S2O3 was1 × 10−4
M.
 The concentration of HCl were also varied like as approach-I
Mixtur
e
4 × 10−4M
KMnO4
4 × 10−4M
Na2S2O3
1M HCl Volum
e Of
H2O
(mL)
Total
Volum
e (mL)Volume
(mL)
Final
Conc.(M
)
Volume
(mL)
Final
Conc.(M
)
Volume
(mL)
Final
Conc.(
M)
M-2-1
5.0
1 ×
10−4
5.0 1 × 10−4
0.2 0.01 9.80
20.00
M-2-2 2.0 0.10 8.00
M-2-3 4.0 0.20 6.00
M-2-4 6.0 0.30 4.00
M-2-5 8.0 0.40 2.00

13. Medicinal application of the OintmentExperimental & observation
Preparation of colloidal MnO2
Approach-3
Approach-4
(Aqueous
Condition)
Stability
Investigation of
Colloidal MnO2
solution
Concluding
remark
Approach-1
Approach-2
(Acidic Condition)
 Image Observation:
M-2-1 M-2-2 M-2-3 M-2-4 M-
2-5
 Within a few minutes the MnO2 was precipitated, at first attempted it
looked like a precipitated solution so colloid was not found in
approach-2.

14. Medicinal application of the OintmentExperimental & observation
Preparation of colloidal MnO2
Approach-2
Approach-4
(Aqueous
Condition)
Stability
Investigation of
Colloidal MnO2
solution
Concluding
remark
Approach-1
Approach-3
(Acidic Condition)Mixtur
e
2 × 10−3
M
KMnO4 solution
7.5 × 10−4
M
Na2S2O3 solution
1M HCl
solution
Volum
e Of
H2O
(mL)
Total
Volume
(mL)Volume
(mL)
Final
Conc.(M)
Volume
(mL)
Final
Conc.(M)
Volume
(mL)
Final
Conc.
(M)
M-31
5.0 5 × 10−4
7.50 2.8 × 10−4
0.00 0.00 7.50
20.00
M-3-2 0.20 0.01 7.30
M-3-3 1.0 0.05 6.50
M-3-4 2.0 0.10 5.50
M-3-5 6.0 0.30 1.50
 In this time the resulting concentration of KMnO4 and Na2S2O3 was
5 × 10−4 𝑀 & 2.8 × 10−4 𝑀.
 The concentration of HCl were also varied from 0.01M to 0.3M.

15. Medicinal application of the OintmentExperimental& observation
Preparation of colloidal MnO2
Approach-2
Approach-4
(Aqueous
Condition)
Stability
Investigation of
Colloidal MnO2
solution
Concluding remark
Approach-1
Approach-3
(Acidic Condition)
 Image Observation:
M-3-1 M-3-2 M-3-3 M-3-4 M-
3-5
 Within 2 hours the MnO2 precipitated, so colloid was not found in this approach.
So from the above observation it was found that the acidic condition was not
suitable for the MnO2 colloidal.
 For this reason another condition (like as aqueous) was applied.

16. Experimental& observation
Approach-4
(Aqueous
Condition)
Stability
Investigation of
Colloidal MnO2
solution
Concluding
remark
Preparation of colloidal MnO
Approach-2
Approach-3
02/11/2015 03/11/2015
Approach-1 Now the approach was done in aqueous condition, where the resultant
concentration of KMnO4 was fixed but the concentration of Na2S2O3 was varied.
Mixture 0.01M KMnO4
solution
4 × 10−3M Na2S2O3
solution
Volume
Of H2O
(mL)
Total
Volume
(mL)Volume
(mL)
Final
Conc.(M)
Volume
(mL)
Final
Conc.(M)
M-4-1
0.5 𝟏 × 𝟏𝟎−𝟒
0.5 𝟒 × 𝟏𝟎−𝟒 49.00
50.00M-4-2 1.25 𝟏 × 𝟏𝟎−𝟒 48.25
M-4-3 12.5 𝟏 × 𝟏𝟎−𝟑 37.00

17. Experimental& observation
Approach-4
(Aqueous Condition)
Stability
Investigation of
Colloidal MnO2
solution
Concluding
remark
Preparation of colloidal MnO
Approach-2
Approach-3
02/11/2015 03/11/2015
Approach-1 Image Observation
 Proposed about this observation: At this time the satisfactory result
was found and all the mixture were seen like as colloidal but now the
question is that, is it stable or not?
M-4-1 M-4-2 M-4-3

18. Experimental & observation
Stability Investigation of
colloidal MnO2
Concluding
remark
Preparation of
colloidal MnO2
Approach-2
Approach-3
02/11/2015
Stable Colloidal
Approach-1
M-4-1
M-4-2
M-4-3
 Image Observation
M-4-1
M-4-2
M-4-3
Initial
Initial After passing 61
days
After passing 7 days
After passing 3 days
Slightly less stable
Unstable

19. Experimental & observation
Stability
Investigation of
colloidal MnO2
Concluding
remark
Preparation of
colloidal MnO2
Approach-2
Approach-3
02/11/2015 03/11/2015
Approach-1
Approach-4
Approach-5
Mixture 0.01M KMnO4
Solution
4 × 10−3
𝑀 Na2S2O3
Solution
Volume
of
H2O
(mL)
Total
Volume
(mL)
pH
of the
SolutionVolume
(mL)
Final
Conc.
(M)
Volume
(mL)
Final
Conc.
(M)
M-5-1
0.5 1 × 10−4
0.5 4 × 10−5 49 50
5.1
M-5-2 5.5
M-5-3 6.0
M-5-4 6.5
M-5-5 6.7
M-5-6 7.6
M-5-7 8.0
M-5-8 8.5
M-5-9 9.1
 For stability investigation of this colloidal solution at different pH these
mixture was prepared.

20. Experimental & observation
Preparation of
colloidal MnO2
Approach-2
Approach-3
02/11/2015
Approach-1
 Proposed about this observation: Within two days all solution are precipitated and the
MnO2 didn’t stable in this condition. So it remarked that the colloidal were not stable in
acidic and basic condition
 Image Observation
Stability
Investigation of
colloidal MnO2
Concluding
remark
Approach-4
Approach-5

21. Experimental & observation
Preparation of
colloidal MnO2
Approach-2
Approach-3
02/11/2015
Approach-1
Stability
Investigation of
colloidal MnO2
Concluding
remark
Approach-4
Approach-6
(SDS)
Approach-5
Mixture.
0.01M KMnO4
Solution
4 × 10−3 M
Na2S2O3 Solution
0.1 M SDS
Solution Volume
Of H2O
(mL)
Total
Volume
(mL)
Volume
(mL)
Final
Conc.
(M)
Volume
(mL)
Final
Conc.
(M)
Volume
(mL)
Final
Conc.
(M)
CMC
M-6-1
0.5 1 × 10−4
0.5 4 × 10−5
0.33 6.6 × 10−4
48.67
50.0
M-6-2 3.32 6.6 × 10−5
45.68
M-6-3 5 1.0 × 10−2
44.0
M-6-4 33.2 6.6 × 10−2
15.80
 For stability investigation in presence of SDS (anionic surfactant) these mixture
was prepared according to their CMC (critical micelle concentration).

22. Experimental & observation
Preparation of
colloidal MnO2
Approach-2
Approach-3
02/11/2015
Approach-1
Stability Investigation
of colloidal MnO2
Concluding
remark
Approach-4
Approach-6
(SDS)
Approach-5
 Image Observation:
M-6-2
M-6-1
M-6-3
M-6-4
All mixture were
Unstable
Initial
Initial
Initial
Initial

23. Experimental & observation
Preparation of
colloidal MnO2
Approach-2
Approach-3
02/11/2015
Approach-1
Stability
Investigation of
colloidal MnO2
Concluding
remark
Approach-4
Approach-7
(TX-100)
Approach-5
 For stability investigation in presence of TX-100 (Non-ionic surfactant) these
mixture was prepared according to their CMC (critical micelle concentration).
Approach-6
Mixture
0.01M KMnO4
Solution
4 × 10−3 M
Na2S2O3 Solution
1. M /0.001M
TX-100 Solution Volume
Of H2O
(mL)
Total
Volume
(mL)
Volume
(mL)
Final
Conc.
(M)
Volume
(mL)
Final
Conc.
(M)
Volume
(mL)
Final
Conc.
(M)
CMC
M-7-1
0.5 𝟏 × 𝟏𝟎−𝟒
0.5 4 × 10−5
1.35mL of
0.1M
𝟐. 𝟕 × 𝟏𝟎−𝟑
46.90
50.0
M-7-2 5.0mL of
0.1M
𝟏. 𝟎 × 𝟏𝟎−𝟐
43.25
M-7-3 1.35mL of
0.001M
𝟐. 𝟕 × 𝟏𝟎−𝟓
46.90
M-7-4 0.25mL of
0.001M
𝟓. 𝟎 × 𝟏𝟎−𝟔
48.0

24. Experimental & observation
Preparation of
colloidal MnO2
Approach-2
Approach-3
02/11/2015
Approach-1
Stability
Investigation of
colloidal MnO2
Concluding
remark
Approach-4
Approach-7
(TX-100)
Approach-5
Approach-6
 Image Observation:
M-7-2
M-7-1
M-7-3
M-7-4
Initial
Initial
Initial
After passing 48 hours
these solution were
formed precipitation.
M-7-1 was stable
approximately 7 days.

25. Experimental & observation
Preparation of
colloidal MnO2
Approach-2
Approach-3
02/11/2015
Approach-1
Stability
Investigation of
colloidal MnO2
Concluding
remark
Approach-4
Approach-8
(CTAB)
Approach-5
 For stability investigation in presence of CTAB (Cationic surfactant) these
mixture was prepared according to their CMC (critical micelle concentration).
Approach-6
Approach-7
Mixture.
0.01M KMnO4
Solution
4 × 10−3 M
Na2S2O3 Solution
0.1 M /0.001M
CTAB Solution Volume
Of H2O
(mL)
Total
Volum
e
(mL)
Volume
(mL)
Final
Conc.
(M)
Volume
(mL)
Final
Conc.
(M)
Volume Final
Conc.
(M)
CMC
M-8-1
0.5 𝟏 × 𝟏𝟎−𝟒 0.5 𝟒 × 𝟏𝟎−𝟓
4.60mL of
0.1M
9.2 × 10−3
43.65
50.0
M-8-2 5.0mL of
0.1M
1.0 × 10−2
44.37
M-8-3 4.60mL
of 0.001M
9.2 × 10−5
43.65
M-8-4 0.46mL of
0.001M
9.2 × 10−6
47.79

26. Experimental & observation
Preparation of
colloidal MnO2
Approach-2
Approach-3
02/11/2015
Approach-1
Stability
Investigation of
colloidal MnO2
Concluding
remark
Approach-4
Approach-8
(CTAB)
Approach-5
Approach-6
Image Observation:
M-8-2
M-8-1
M-8-3
M-8-4
Initial
Initial
Approach-7
After passing 19 days.
After passing 20 days.
After passing 20 days.
After passing 10 days.
ppt found

27. Result
Preparation of
colloidal MnO2
Approach-2
Approach-3
After several try the concentration was found which gave the
satisfactory result for preparing the colloidal MnO2 solution
(Aqueous media).
The concentration is 1 × 10−4M (KMnO4) and 4 × 10−4M
(Na2S2O3). Which stable approximately 2 months.
In the presence of Cationic surfactant (CTAB) the colloidal
solution of MnO2 also stable but in presence of anionic and
non-ionic surfactant satisfactory result was not found.
Approach-1
Stability
Investigation of
colloidal MnO2
Concluding
remark
Approach-4
Approach-5
Approach-6
Approach-7
Approach-8

28. FOR YOUR KIND ATTENTION