Surface and Interfacial tension [Part-5](HLB System, Solubilization )

This document discusses the HLB (hydrophilic lipophilic balance) system for classifying surfactants. It explains that HLB values indicate whether a surfactant is more hydrophilic or lipophilic. Methods for estimating a surfactant's HLB value involve assigning group numbers to different parts of the molecule. Required HLB values can predict whether a surfactant will form a stable oil-in-water or water-in-oil emulsion with a given oil. However, the HLB system has limitations and does not consider surfactant concentration which also impacts emulsion stability.