HLB value

HLB value ( HLB stands for engl. H ydrophilic- l ipophilic b alance) describes the chemistry of the hydrophilic and lipophilic portion of mainly non-ionic surfactants and was proposed in 1954 by Griffin WC.

Griffin's method

HLB values ​​and usage
HLB value use Miscibility with H 2 O
1.5 to 3 Defoamer insoluble
3 to 8 for W / O emulsions milky when stirring
7 to 9 Wetting agents
8 to 18 for O / W emulsions stable (milky) emulsion
13 to 15 Active washing substances clear emulsion / clear solution
12 to 18 Solubilizer clear emulsion / clear solution

HLB value for nonionic surfactants can be calculated as follows:

${\ displaystyle \ mathrm {HLB = 20 \ times \ left (1 - {\ frac {M_ {l}} {M}} \ right)}}$

where M l is the molar mass of the lipophilic portion of a molecule and M is the molar mass of the entire molecule. The factor 20 is a scaling factor freely selected by Griffin. This results in a scale from 0 to 20. An HLB value of 1 indicates a lipophilic compound, a chemical compound with an HLB value of 20 has a high hydrophilic content. A value between 3 and 8 is assigned to W / O emulsifiers , 8–18 O / W emulsifiers. Laundry detergents have HLB values ​​between 13 and 15. Phospholipids have a value of 5 and lysophosphatides 12–16.

Davies method

In addition to the Griffin method, there are other methods of calculating the HLB value. However, these are far less common. Only the method according to Davies should be mentioned here, who proposed in 1957 to calculate the HLB value from numerical values ​​for the individual chemical groups of a molecule. The advantage of this method is the higher weighting of strongly interacting groups compared to less interacting ones. In addition, the HLB value for cationic and anionic surfactants can be defined in this way. According to Davies, the HLB value is calculated as follows:

${\ displaystyle \ mathrm {HLB \ = \ 7 \ + \ m \ cdot \ H_ {h} \ - \ n \ cdot \ H_ {l}}}$

With:

m: number of hydrophilic groups in the molecule
H h : value of the hydrophilic group
n: number of lipophilic groups in the molecule
H l : value of the lipophilic group

Individual evidence

1. a b Hans-Dieter Dörfler, Grenzflächen- und Kolloidchemie , VCH, Weinheim, 1994, p. 198.

literature

• WC Griffin: Classification of surface active agents by HLB. In: J. Soc. Cosmet. Chem. 1, 1949, pp. 311-326.
• G. Brezesinski, H.-J. Mögel: interfaces and colloids. Spectrum Academic Publishing House, Heidelberg / Berlin / Oxford 1993, ISBN 3-86025-016-7 .