Sodium salt admixtures for enhancing the foaming characteristics of sodium lauryl sulphate

Abstract

This study identifies admixtures to enhance the effectiveness of Sodium Lauryl Sulphate (SLS) as a foaming agent by increasing the foam density and stability. Sodium hydroxide, sodium carbonate and sodium chloride were chosen based on common ion effect to increase the viscosity of the foaming solution in order to achieve ASTM recommended range of foam density. Response surface methodology is used to study the responses like viscosity, foam density and foam stability of all the admixtures. Viscosity is observed to have a linear relationship with foam density, bubble size distribution and stability. Foam density increases with the dosage of admixture, irrespective of foam generation pressure (FGP). Use of appropriate dosage of these admixtures with SLS provides the foam density specified by ASTM. Relatively lesser dosage of NaOH is sufficient to achieve ASTM recommended foam density, which is attributed to the fact that mole percent of sodium in NaOH is higher than NaCl and Na2CO3. The stability of the foam has also been demonstrated through a typical mix of foam concrete.