HSP Application note #32
Surfactant and Hansen Solubility Parameter (HSP)2010.4.17
HSPiP Team Senior Developer, Dr. Hiroshi Yamamoto
| Under CMC | Surfactant begin to make Micelle Critical Micelle Concentration(CMC) |
Critical Micelle Concentration (CMC)
Name |
C# |
cmc(mmol) |
melting point |
logP |
logS |
butyric acid Na salt |
4 |
|
-5.15 |
0.79 |
0.778 |
pentanoic acid Na salt |
5 |
|
-33.95 |
1.39 |
0.3802 |
hexanoic acid Na salt |
6 |
|
-3.85 |
1.92 |
-0.014 |
heptanoic acid Na salt |
7 |
|
-7.27 |
2.42 |
-0.611 |
octanoic acid Na salt |
8 |
360 |
16.55 |
3.05 |
-1.167 |
nonanoic acid Na salt |
9 |
|
12.45 |
3.42 |
-1.75 |
decanoic acid Na salt |
10 |
95 |
31.65 |
4.09 |
-2.44 |
undecanoic acid Na salt |
11 |
|
28.53 |
4.42 |
-2.55 |
Lauric Acid Na salt |
12 |
27.5 |
44.2 |
4.6 |
-3.318 |
tridecanoic acid Na salt |
13 |
|
41.91 |
|
-2.57 |
myristic acid Na salt |
14 |
7.2 |
54.4 |
6.11 |
-3.971 |
pentadecanoic acid Na salt |
15 |
|
52.58 |
|
|
palmitic acid Na salt |
16 |
1.9 |
62.9 |
7.17 |
-5.398 |
heptadecanoic acid Na salt |
17 |
|
61.15 |
|
|
Stearic acid Na salt |
18 |
0.5 |
69.6 |
8.23 |
-4.224 |
nonadecanoic acid Na salt |
19 |
|
68.13 |
|
|
Oleic acid Na salt |
18 |
1 |
13.4 |
7.73 |
-6 |
linoleic acid Na salt |
18 |
2 |
-5.1 |
7.05 |
-5 |
|
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Acid form |
Acid form |
Acid form |
I compiled CMC data for surfactant.
I happen to plot logCMC to logP of Carboxylic Acid (Acid form).
There is so beautiful correlation!
So, I found that Critical Micelle Concentration is governed by logP value.
As I wrote in User’s Forum article, logP just means Volume.
I compiled more CMC data and check this phenomena.
As same with logP, logCMC has very beautiful correlation with HSP Volume.
I can estimate CMC from Volume and type of hydrophilic structure
Hydrophobic structure: it means just molecular volume.
Fluorinated, aromatic, hydrocarbon, that does not matter. JUST VOLUME!
Hydrophilic structure: almost all coefficient is around 2 except Ethylene Oxide.
Overall, logCMC is governed by only Hydrophobic structure’s volume.
So, logCMC estimation scheme and HLB scheme say same thing.
If you plot Fluoro-compounds with HLB (calculated by mass) fluoro-compounds are heavy and HLB become small.
But if you plot with molecular volume calculated by HSPiP, it become identical line.
If you draw molecule and put X atom at the hydrophpilic part, then calculate, program will calculate CMC. This program do not support -OCH2CH2- type of surfactants. If you want to know how to draw molecules, please refer to Helper applications.
How many molecules aggregate in Micelle?
Something dissolve into micelle,
Volume increase, then surface increase,
new surfactant fill new surface and surfactant hydrophobic part increase volume.
HLB and logP is very similar concept.
But both logP and HLB is not solubility indicate.
So, there is no correlation with HSP.
After surfactant make micelle, HSP play very important role.
I got the mail about CMC of sulfosuccinates surfactant.
Sulfosuccinates have two tails.
If the total hydrophobic volume is same, CMC is ten times larger for Sulfosuccinate.
For example, C6H13OOCCH2CH(SO3Na)COOC6H13 volume is 296 and CMC is 12.
C17H35So3Na, volume is 301 and CMC is 0.21.
C14H29-Ph-SO3Na, volume is 315 and CMC is 0.66.
So, with same hydrophobic volume, Sulfosuccinate have 10 time more micelle volume.
It will very good for detergent.
I search for aggregation number about Sulfosuccinates, but in vain.
If you have the data, please let me know.
Then I can say which size, how many micelle exist for certain surfactant.
Then I want to know how much oil solve to this system.
That case HSP will play very important role.
Please read article about liquid-liquid extraction .
2011.6.11
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