Thermodynamic parameters of clouding phenomenon in nonionic surfactants: The effect of the electrolytes
Küçük Resim Yok
Tarih
2017
Yazarlar
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Elsevier Science Bv
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
In this study, the thermodynamics of the cloud point (CP) of the two non-ionic surfactants, polyoxyethylene (40) iso octylphenyl ether, (TX-405) and polyoxyethylene (23) lauryl ether, Brij-35 were investigated in different electrolyte concentrations. In the measurements of cloud point temperatures, UV-visible spectrophotometer was used instead of visual observation. Li2SO4, Na2SO4, KNO3, K2SO4, K3PO4 and (NH4)(2)SO4 were used as electrolytes. Thermodynamic parameters were calculated from cloud point values of nonionic surfactant-electrolyte mixtures. The CP values in the presence of KNO3 were obtained by an extrapolation of the straight line. The results of the energetics of clouding showed that the standard Gibbs free energy (triangle G(cp)(o)) was positive but the enthalpy (triangle H-cp(o)) and the entropy (triangle S-cp(o)) were negative in all cases. Furthermore, the enthalpy-entropy compensation relationship was estimated and the compensation temperature values (Tc) values were found as 389.70 K and 391.19 K for TX-405 and Brij-35, respectively. (C) 2017 Published by Elsevier B.V.
Açıklama
Anahtar Kelimeler
Cloud Point, Phase Separation, Nonionic Surfactant, Thermodynamic Parameters, Enthalpy-Entropy Compensation, Enthalpy-Entropy Compensation, Drug Imipramine Hydrochloride, Triton X-100, Organic Additives, Aqueous-Solutions, Phase-Separation, Point, Behavior, Micellization, Mixtures
Kaynak
Journal Of Molecular Liquids
WoS Q Değeri
Q1
Scopus Q Değeri
Q1
Cilt
231
