## Cc Values

### Quick Start

To use HLD we need the characteristic value of our surfactant, its Cc. We might be able to find it in the list below. We might be able to measure it. But if it's a mixture, or if we want to tune the Cc rationally, then we need to calculate the value of the mixture. Easy! It's the molar-based average of the individual surfactants, so we need the weight % and the MWts of the two surfactants.

### Cc Values

Cc1
Cc2
MWt1
MWt2
Cc1 Wt%
Cc

Each surfactant is characterised by a Cc value. A very hydrophilic surfactant such as SLS has Cc = -2.3 and a hydrophobic surfactant such as AOT has Cc = 2.6. But what is Cc? The name was originally Characteristic Curvature which seemed a good idea at the time. There are some thermodynamic reasons why the name might be thought appropriate. But the truth is that the name really has no helpful meaning. Let's just call it Cc (perhaps imagine it meaning Characteristic) because that's what is generally used in the literature.

More important than the name are the values. Heroic research over a number of years has produced a set of values for some common surfactants. Not all the values are perfectly accurate (partly because "the same" surfactant from one supplier can often be different from "the same" surfactant from another supplier), but they are generally a good starting point. Below is a list of values assembled with "best endeavours" - feel free to suggest better values or to add new ones to the list.

### Cc of blends

If your surfactant isn't quite what you want (or to put it another way, if you want to tune your system by varying the surfactant) a most convenient fact is that the Cc of a mixture of surfactants is the mole weighted average of the Ccs of the surfactants. Because it is the mole-weighted average the MWt of each surfactant needs to be known. You get more "bang for your %Cc" with a small MWt surfactant. The calculator at the top of the page does the hard work for you.

To get used to the calculations it can be a good idea to set % = 50 and Cc1 = -1 and Cc2 = 1. If the MWt values are identical then the Cc of the mix should be 0. If you increase the MWt of #1 then there will be fewer moles of #1 in the mix so the Cc increases towards the value set by #2. Decreasing the MWt of #1 sends the Cc towards that of #1. The effect of the MWts of surfactants are another complication of surfactant space which often causes confusion. With HLD apps the molar mixing rule is always taken into account.

Surfactant
Cc
Surfactant
Cc
C6EO2
2.4
SDHS Na Dihexylsulfosuccinate
-0.92
C6EO3
0.1
SDBS Na Dodecyl Benzene Sulfonate
-0.9
C6EO4
-1.6
SDOS/AOT Na Dioctyl sulfosuccinate
2.55
C8EO3
1.8
SDS/SLS Na Dodecyl Sulfate
-2.3
C8EO4
0.3
Sodium Octanoate
-3
C8EO5
-1
Sodium Decanoate
-2.55
C10EO4
1.3
Sodium Didecanoate
-2.1
C10EO5
0.1
-1.2
C10EO6
-0.9
Sodium Stearate
-0.75
C12EO4
2
Sodium Oleate
-1.7
C12EO5
0.8
Oleic Acid
0
C12EO6
-0.2
Sodium Dimethylnaphthalene sulf.
-3.5
C11.5EO5
0.31
Sodium Strearoyl Glutamate
-5
C12EO6.5
-1.2
Lecithin
4
C14EO7
-0.7
NaC12PO4Sulfate
-1.9
iC13EO8
-0.1
NaC12PO6Sulfate
-1.6
C12-16EO14
-2.9
NaC12PO8Sulfate
-1.3
C9PhEO2
1
NaC12PO10Sulfate
-1
C9PhEO5
0.12
NaBranchedC12PO4Sulfate
-1.4
C9PhEO9
-1.6
NaBranchedC12PO6Sulfate
-1.1
PolySorbate 20 (Tween 20)
-7.9
NaBranchedC12PO8Sulfate
-0.8
PolySorbate 80 (Tween 80
-3.7
NaBranchedC12PO10Sulfate
-0.5
Sorbitan Monolaurate (Span 20)
3.5
NaBranchedC14PO8Sulfate
-0.6
Sorbitan Monooleate (Span 80)
3.1
NaC12PO14EO2Sulfate
0.74
Sucrose Palmitate
-0.8
NaC10PO18EO2Sulfate
1.99
Sucrose Distearate
4
CTAB (Cetyl-Me3 N+ Br- )
-5.7 k=0.71
C10Glucoside
-1.7
MTAB (Miristyl-Me3 N+ Br- )
-8.4 k=0.71
C12Glucoside
1.3
LTAB (Lauryl-Me3 N+ Br- )
-10.0 k=0.71
APG8-10
-1.5
CMIC
-7.0 k=0.71
APG12-14
-1
BDHC
0.1 k=0.71
Rhamnolipid 50:50 R1:R2
-1.4
DDAB
8.3 k=0.71
Sophorolipid Lactone
4.5
C12Gly2
1.2

### Manufacturers Cc values

It has always seemed obvious to me that manufacturers would want their Cc values to be known. But progress is slow. I had, unfortunately, missed the fact that Sasol had published2 an interesting set of their own values, though the academic paper made it a little hard to translate into user-friendly values. Thanks to the help of Dr Thu Landry (Nguyen), I can now provide this table of their values. Their alkyl chains such as FT-Oxo are described in their paper and on their website but are basically diffent types of branching:

Surfactant
Cc
Surfactant
Cc
FT-Oxo C12-13 5EO
0.3
FT-Oxo C12-13 4EO
1.1
TDA 5EO
-0.1
TDA 3EO
1.0
FT-Oxo C12-13 6.5EO
-1.4
TDA 6EO
-1.1
TDA 8EO
-1.8
FT-Oxo 23 7PO0EO Sulfate
-1.3
FT-Oxo 23 7PO1EO Sulfate
-1.1
FT-Oxo 23 7PO3EO Sulfate
-1.5
Ziegler 7PO3EO Sulfate
-1.6
FT-Oxo C12-13 7PO3EO Sulfate
-1.5
Oxo C12-13 7PO3EO Sulfate
-1.3
Br-Oxo C12-13 7PO3EO Sulfate
-1.0
FT-Oxo C12-13 12PO3EO Carboxylate
-0.77
Br-Oxo C12-13 15PO3EO Carboxylate
-0.2
Ziegler C8 0PO7EO Carboxylate
-3.3
Ziegler 0PO3EO Carboxylate
-2.5
TDA 0PO7EO Carboxylate
-2.5
TDA 3PO7EO Carboxylate
-1.5
Ziegler C12-14 0PO4.5EO Carboxylate
-1.9
Ziegler C12-14 0PO3EO Carboxylate
-1.7
Guerbet C12 0PO5EO Carboxylate
-1.1
Guerbet C12 2PO1EO Carboxylate
0.6
Ziegler C16-18 4.5PO5EO Carboxylate
0.2
Ziegler C16-18 4.5PO2EO Carboxylate
1
Oxo C16-17 2.7PO1EO Carboxylate
0.8

1Davide Schirone, Giuseppe Tartaro, Luigi Gentile, Gerardo Palazzo, An HLD framework for cationic ammonium surfactants, JCIS Open 4 (2021) 100033

2Thu T. Nguyen, Carla Morgan, Laurie Poindexter, Jorge Fernandez, Application of the Hydrophilic–Lipophilic Deviation Concept to Surfactant Characterization and Surfactant Selection for Enhanced Oil Recovery, J Surfact Deterg, 22, 983-999, 2019