Home › Cosmetic Science Talk › Formulating › How much to dilute 70% SLES gel so it becomes liquid?
-
How much to dilute 70% SLES gel so it becomes liquid?
Posted by Gunther on August 1, 2018 at 1:23 amDilute it by half, down to 35%? 30%
Do you need a preservative when it becomes liquid?DAS replied 6 years, 2 months ago 7 Members · 7 Replies -
7 Replies
-
There are commercial SLES solutions at 26-27% which are liquids. My guess it should be liquid even at 35%, but it should be tested.
Regarding preservatives, I’ve seen without, but I guess it depends on the shelf life. -
between around 30 and 65% w/w it forms a crystalline phase which is completely rigid, and much harder to process than the lamellar phase it forms at 70% and above - this is why it’s sold as 70%, 28% or lowerwhether or not it needs preservatives depends on the pH of the dilution; dilutions without preservatives are around pH 12, and use their high alkalinity as preservationin my experience, industrial-scale dilution tends to be carried out using a specialist (and complex) Bran-Luebbe mixer like this one
-
When SLES70% is converted into SLES27%, it diluted by a lot of water,
At the same time the osmolarity of the solution decreases, due to a lower concentration of salts,
Which gives room for bacterial growth.In my factory we consume large quantities of SLES70%, and sometimes in the winter we use SLES27%.
Solutions of SLES27% are manufactured according to factory orders and are with the same preservation system as the plant uses and at its request. -
Bill_toge is right, at around 30% in water SLES form an hexagonal liquid crystalline phase that is very viscous. The concentration limits of the phases may vary a lot depending the impurities contained in the different batches of SLES. I guess that the hexagonal phase is present in a large range of temperature (is is the case for SDS not sure with SLES).
Log in to reply.