- International Journal of Thermodynamics
- Vol: 14 Issue: 3
- Thermodynamics of Philicphobic Interaction Shift in Aqueous Tweens 20 to 80
Thermodynamics of Philicphobic Interaction Shift in Aqueous Tweens 20 to 80
Authors : Man SİNGH
Pages : 135-146
View : 8 | Download : 1
Publication Date : 2011-07-25
Article Type : Other
Abstract :Density (ρ ± 10 -3 kg m -3 ), surface tension (γ ± 10 -2 mNm -1 ) for 8.4 to 83.6 mmolkg -1 at 8 m molkg -1 interval aqueous polyoxyethylene sorbitan monolaurate (C=12, Tw20), monopalmitate (C=16, Tw40), monostearate (C=18, Tw60) and monooleate (C=18, 1 double bond, Tw80) nonionic surfactants at 293.15 K are reported. Apparent molar volumes (V 2 ) are derived from densities. The γ is used for surface excess tension (γ excess ), concentration (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 (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 (CF) and 22.68% with T60.Keywords : Intermolecular forces, density, excess surface tension, area per molecule, tweens, micelles, molar volume