@Perry @Graillotion you are right but i wanted to know this specific answer.
I thought stearyl and cetearyl increase the viscosity more than Cetyl Alcohol because they have higher melting point but yesterday i saw this post on makingskincare.com website.
Stearyl alcohol produces a whiter and more opaque product due to it’s longer carbon chain length. Cetyl alcohol breaks more easily when applied so gives a quicker spread and can hold onto more water than stearyl alcohol as it is more hydrophilic. This results in a higher gel phase which means a higher viscosity. However stearyl alcohol has a different crystalline structure and is less polar resulting in a a more stable viscosity, unlike cetyl alcohol whose viscosity can increase over time.
I currently use cetearyl alcohol 30/70.
This formula Petrolatum %5 Coconut oil %2 Dimethicone %1 Polyglyceryl 6 distearate %1 Glyceryl stearate %1 Cetearyl alcohol %3 Glycerin %20 Preservative, essential oil and water. pH 5
Would the viscosity increase or decrease if i use Cetyl Alcohol instead of cetearyl alcohol?
“Would the viscosity increase or decrease if i use Cetyl Alcohol instead of cetearyl alcohol? ” - I don’t know. You have to run the experiment in your system and find the answer.
But the real answer is, the system is too complicated to simply say whether it will increase or decrease the viscosity. There are factors of solubility, polarity, ingredient purity not to mention particle size, forces involved during mixing, etc. Unless you create a phase diagram you have no idea of what the crystalline structure will be.
All the stuff written about it from makingskincare is just theoretical musings about some imagined idealized formula.
People generally use Cetearyl Alcohol because having a blend of fatty alcohols leads to a more stable formula than single fatty alcohols. But then again, it depends on the system.