HYDROPHILE-LIPOPHILE BALANCE OF ALKYL ETHOXYLATED SURFACTANTS AS A FUNCTION OF INTERMOLECULAR ENERGIES

The semiempirical MNDO method has been used in order to examine the va riation of the molecular properties of hydrocarbons CnH2n+2(with 1 les s than or equal to n less than or equal to 19) and ethylene oxide chai ns CH3(CH2CH2O)(M)CH3 (with 1 less than or equal to m less than or equ al to 19) as a function of their molecular length. Least-square fits o f those properties have been calculated, along with two mathematical r elations between the hydrophile-lipophile balance of alkyl-phenol etho xylated surfactants and (1) the ratio of molecular lengths between the ir lipophilic and hydrophilic branches; (2) the intermolecular energie s between the molecules of surfactant, water and hexane.