Phase separation phenomena and thermodynamics of octylphenol polyoxyethylene ether in micellar solutions: Effect of high concentration of inorganic salts and linear correlation

Li, Dan Ni; Huang, Jing; Ren, Zhao Hua; Sheng, Rui; Qian, Zheng Bo; Li, Bei Bei; Quan, Xiao Feng; Zhang, Ye Xi; Wang, Jun Ru; Tian, Huan

doi:10.1016/j.jiec.2021.04.027

Cited by 17 publications

(4 citation statements)

References 36 publications

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“…Solubilization of the copolymer is accompanied by elevation in CP. 30,31 Thermodynamic aspects of salt-induced changes in the copolymers were elucidated by ITC experiments. The shape of ITC profile is influenced by the copolymer concentration, nature of aggregates, and solution conditions (Figure S3 of the Supporting Information).…”

Section: ■ Results and Discussionmentioning

confidence: 99%

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Comparative Effect of Physiological Salts upon Micellization of T1304 and T1307

et al. 2023

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We present a comprehensive investigation on the interaction of tetronics (T1304 and T1307) with some important physiological salts (NaH2PO4, KH2PO4, Na2CO3, NaCl, and KI). Thermodynamic and microstructural aspects of these interactions were studied as a function of the solution temperature, pH and salt concentration. Characterizations were performed using turbidimetric, calorimetric, and scattering techniques. We show that, at ambient temperature, T1304 molecules aggregated to form spherical core–shell aggregates displaying a unimodal distribution pattern. On the other hand, unimers and large clusters dominated in the case of highly hydrophilic T1307. Its micellization was promoted in the presence of salts as per the following trend: NaCl < KH2PO4 < NaH2PO4 ≪ Na2CO3. Aggregation was found to be endothermic, and hydrophobic interactions (TΔS mic > ΔH mic) prevailed. The enthalpy–entropy compensation plot was found to be linear for both copolymers. Demicellization occurred in the presence of KI as it facilitated the buildup of water structures around the copolymer chains. This could be verified from the increase in the cloud point, critical micelle concentration, and free energy. Overall, the temperature and salts inflicted a stronger hydrophobic effect upon T1304 in comparison to T1307.

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Section: ■ Results and Discussionmentioning

confidence: 99%

“…In such a situation, non-associated water molecules are free to engage with the copolymer. Solubilization of the copolymer is accompanied by elevation in CP. , …”

Section: Resultsmentioning

confidence: 99%

Comparative Effect of Physiological Salts upon Micellization of T1304 and T1307

et al. 2023

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“…The change in entropy is dominant during the clouding process. Both enthalpy and entropies are negative, indicating that the hydrogen bonding and dipole-dipole interaction exist in between the components of the solution [35]. The stabilized solution is formed by the formation of heavy aggregates of surfactant and is governed by negative entropy.…”

Section: Discussionmentioning

confidence: 99%

“…The additives consisting electrolytes, macromolecules, and ionic surfactants, tuned the CP of nonionic surfactants which have been reported by a number of researchers [29]- [34]. The bulky structured organic and inorganic species also affect the phase behavior of nonionic surfactants was well explained by many researchers [35]- [39]. The results of alcohol additives on the CP of polyoxyethylene (7.5) nonyphenyl ether nonionic surfactant indicates that the introduction of small-chain aliphatic alcohols enhances the CP while the introduction of long-chain alcohols lowers the cloud point of polyoxyethylene (7.5) nonyphenyl ethe [40].…”

Section: Introductionmentioning

confidence: 89%

Tuning of Coacervate Phase Behavior of Polyoxymethylene (4) Lauryl Ether in Aqueous Alcoholic Solution: Investigation of Thermodynamics

Borse,

Nikam,

Jadhav

2023

EJCHEM

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In case of non-ionic surfactant, the phase partition behavior (CP) of micellar solution was vary under the influence of various additive mixed systems. The non-ionic surfactant in an aqueous medium shows phase separation above the critical micelle concentration (CMC), There is a change in micellar interactions at cloud point (CP) with increase in temperature. The insertion of foreign material to surfactant solution alters the clouding temperature. In this paper we report how cloud point varies with addition of alcohol as additives. For non-ionic surfactant Polyoxyethylene (4) lauryl ether (Brij-30) the CP temperature was investigated at variable concentrations of surfactant in pure and additive mixed systems. The results we obtained shows that cloud point of pure Brij-30 surfactant decreases with enhancement in surfactant concentration from 1% to 10% (w/v) in a 22% aqueous ethanolic medium. Similarly, the cloud point values of Brij-30 in presence of n-alcohols shows increasing trend in case of propanol and butanol, specifying that their solubilization helps to form swollen water structures, thus favoring micelle hydration, while the presence of alcohols like pentanol, hexanol and heptanol shows a decreasing trend with increasing micelle size. The change in cloud points of Brij-30 in participation of various n-alcohols plays an important role in demonstrating the effect of the nature of additives on the stability of micelle. The foam ability and foam stability data discusses the stability of micelle aggregation. The important information about the thermodynamic entities were calculated using “Phase Separation Model”.

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