Thermodynamics of Philicphobic Interaction Shift in Aqueous Tweens 20 to 80

Authors : Man SİNGH

Pages : 135-146

View : 10 | Download : 5

Publication Date : 2011-07-25

Article Type : Research Paper

Abstract :Density insert ignore into journalissuearticles values(ρ ± 10 -3 kg m -3 );, surface tension insert ignore into journalissuearticles values(γ ± 10 -2 mNm -1 ); for 8.4 to 83.6 mmolkg -1 at 8 m molkg -1 interval aqueous polyoxyethylene sorbitan monolaurate insert ignore into journalissuearticles values(C=12, Tw20);, monopalmitate insert ignore into journalissuearticles values(C=16, Tw40);, monostearate insert ignore into journalissuearticles values(C=18, Tw60); and monooleate insert ignore into journalissuearticles values(C=18, 1 double bond, Tw80); nonionic surfactants at 293.15 K are reported. Apparent molar volumes insert ignore into journalissuearticles values(V 2 ); are derived from densities. The γ is used for surface excess tension insert ignore into journalissuearticles values(γ excess );, concentration insert ignore into journalissuearticles values(τ); and area per molecule. The ρ and γ were regressed for ρ 0 and γ 0 limiting and slopes for shift from hydrophilic to hydrophobic interactions insert ignore into journalissuearticles values(philicphobic);. The ρ 0 Tw20 >ρ 0 Tw40 >ρ 0 Tw80 > ρ 0 Tw60 and V 2 0 Tw60 > V 2 0 Tw40 > V 2 0 Tw80 > V 2 0 Tw20 as limiting densities and molal volume respectively in opposite order with stronger structural interaction with Tw20 and weaker with Tw60. The γ water >γ 0 Tw80 >γ 0 Tw40 >γ 0 Tw20 >γ 0 Tw60 inferred 18% weaker cohesive force insert ignore into journalissuearticles values(CF); and 22.68% with T60.
Keywords : Intermolecular forces, density, excess surface tension, area per molecule, tweens, micelles, molar volume