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Preparation of a New Oligomeric Surfactant: N , N , N ′, N ″, N ″‐Pentamethyl Diethyleneamine— N , N ″‐Di‐[Tetradecylammonium Bromide] and the Study of its Thermodynamic Properties
Author(s) -
Alehyen Saliha,
Bensajjay Fatima,
El Achouri Mohammed,
Pérez Lourdes,
Pinazo Aurora,
Infante María Rosa
Publication year - 2010
Publication title -
journal of surfactants and detergents
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.349
H-Index - 48
eISSN - 1558-9293
pISSN - 1097-3958
DOI - 10.1007/s11743-009-1162-2
Subject(s) - chemistry , pulmonary surfactant , surface tension , gibbs isotherm , gibbs free energy , critical micelle concentration , thermodynamics of micellization , counterion , standard molar entropy , molar conductivity , enthalpy , aqueous solution , bromide , analytical chemistry (journal) , thermodynamics , standard enthalpy of formation , inorganic chemistry , micelle , organic chemistry , ion , biochemistry , physics
A new oligomeric surfactant: N , N , N ′, N ″, N ″‐ pentamethyl diethyleneamine— N , N ″‐di‐[tetradecylammonium bromide] referred to as 14‐2‐N(CH 3 )‐2‐14 was synthesized, purified and characterized by Elemental Analysis, 1 H and 13 C NMR and Electrospray. The micellar properties of this compound were determined by electrical conductivity and surface tension methods. Optical microscopy was also employed to study the behavior of anhydrous surfactant and the binary water/surfactant system as a function of temperature. The critical micellar concentration (cmc), degree of counterion binding and thermodynamic parameters of micellization (standard molar Gibbs energy, enthalpy and entropy of micellization) were determined by electrical conductivity measurements in the temperature range [24–54 °C]. Surface tension measurements also provide information about the dependence of the surface tension at the cmc (γ cmc ), pC 20 (negative logarithm of the surfactant's molar concentration C 20 , required to reduce the surface tension by 20 mN/m, the surface excess (Γ max ) at air/solution interface, the minimum area per surfactant molecule at the air/solution interface (Amin), surface pressure at the cmc (П cmc ), critical packing parameter(CPP) and the standard free energies of micellization ( Δ G m 0 ) and of adsorption ( Δ G ads 0 ).