• B. B. Patil
• G. H. Sonawane

The cloud point (CP), temperature for aqueous solution of Polyoxyethylene (10) oleyl ether (Brij-97) and in the presence of added polymer PEG4000 and PEG6000 at various concentrations was investigated. It is observed that CP of Brij-97 decreases with increasing concentration. At fixed concentration of surfactant the cloud point of Brij-97-PEG4000 mixed system shows decreasing order/trend with increasing concentration of PEG4000, while the cloud point of Brij-97-PEG6000 mixed system shows increasing trend with increasing concentration of PEG6000. The thermodynamic parameters of these pure and mixed systems are determined at different additive concentrations. The standard Gibb’s free energy, enthalpy and entropy were found to be positive for both PEG4000 and PEG6000. The overall clouding process was endothermic and non-spontaneous. The CP of pure Brij-97 was found to be decreased from 56.2 to 54.5 with increasing concentration of Brij-97 from 0.5% to5%. The cloud point of mixed system shows decreasing trends with increasing concentration of Brij-97.

Cloud point, nonionic surfactant, phase separation model thermodynamic parameters.

"Effect of molecular weight of PEG on the cloud point of Polyoxyethylene (10) oleyl ether (Brij-97). - A Thermodynamic approach", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.6, Issue 2, page no.386-395, February-2019, Available :http://www.jetir.org/papers/JETIR1902856.pdf

"Effect of molecular weight of PEG on the cloud point of Polyoxyethylene (10) oleyl ether (Brij-97). - A Thermodynamic approach", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.6, Issue 2, page no. pp386-395, February-2019, Available at : http://www.jetir.org/papers/JETIR1902856.pdf