HEC thick layer separating

HEC was able to thicken bare water, but when attempting to thicken a CAPB + decyl glucoside formulation a thick layer sinks to the bottom, leaving a thin, liquid layer on top.

deionized water 50 vol%
Hydroxyethyl cellulose 2 wt%
it got much thicker a couple hours later

added a tiny amount of dilute NaOH
some entrapped bubbles from stirring, but same viscosity remains.

water q.s. to 100% (about 50 vol%)
if becomes less viscous, with some bubbles

Now the total volume is 150% of the original one
Dehyton-K to 7% active CAPB
Generic Decyl glucoside to 3% active Decyl glucoside

citric acid qs to pH 6


The solution never thickens while stirring
if allowed to rest, a viscous layer sinks to the bottom, while a water thin layer remains on top.
How to solve this?


  • I have said this around here :smile: HEC has incompatibilities with some surfactants. I learned it the hard way myself 
    I simply removed HEC and solved the viscosity with NaCl. You may try HPMC instead. 
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