Hi Fatma,

The standard book on surfactant CMC values is by Mukerjee and Mysels ( can be dowloaded by copy-pasting this link: https://nvlpubs.nist.gov/nistpubs/Legacy/NSRDS/nbsnsrds36.pdf ).

You will not find Tween 60 and Span 80 as these are trade names, rather search for them by their molecular structure in the Mukerjee, Mysels book.

The Tween series you will find here: https://globaljournals.org/GJSFR_Volume13/1-Effect-of-Temperature-Changes-on-Critical.pdf

Spans are so badly soluble in water (very low HLB-values) that one cannot talk about a water -CMC value and thus these values are not reported anywhere.

Kind regards, Leo

Link to the proposed Leo Vleugels

P. Mukerjee and K.J.Mysels. Critical micelle concentrations of aqueous surfactant systems. Natl. Stand. Ref. Data. Ser., Natl. Bur. Stand. Washington

D.C. 36, 1971

You can find information also in more new book https://www.elsevier.com/books/physico-chemical-properties-of-selected-anionic-cationic-and-nonionic-surfactants/van-os/978-0-444-89691-9

Authors: N.M. van Os J.R. Haak L.A.M. Rupert

eBook ISBN: 9780444600288

Imprint: Elsevier Science Published Date: 29th March 1993

Many thanks

@sergie nikolaevich

@yuri migorod

@leo vleugels

The catalogues of manufacturers like https://www.anatrace.com/Products/ often contain useful info on their products. However, cmc and \bar{m} depend on temperature and the composition of the solution (salt concentration, pH...). In the end you need to determine it yourself for the conditions you are working under, see for example doi:10.1006/abio.1993.1039 or doi:10.1016/0003-2697(84)90026-5.