Polyelectrolyte-Surfactant Interactions: Polymer Hydrophobicity, Surfactant Aggregation Number, and Microstructure of the Systems

2020 ◽  
pp. 409-454
Author(s):  
Raoul Zana
2019 ◽  
Vol 10 (41) ◽  
pp. 5578-5583 ◽  
Author(s):  
Takumitsu Kida ◽  
Ryo Tanaka ◽  
Koh-hei Nitta ◽  
Takeshi Shiono

The increase of aggregation number in a star-shaped cyclic olefin copolymer was succeeded by using a triazine-based secondary amine, which caused a drastic change in physical properties without changing the thermal properties.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Vikrant Abbot ◽  
Poonam Sharma

AbstractFlavonoids amongst the class of secondary metabolites possess numerous health benefits, are known for its use in pharmaceutical industry. Quercetin, a flavonoid has more prominent medical advantages however its utilization is constrained because of various instability and insolubility issues and therefore, taken into consideration for studying its physico-chemical properties. In view of that, the thermodynamic and thermoacoustic properties of quercetin were examined in presence of cationic surfactant cetyltrimethylammonium bromide (CTAB) at different hydroethanolic concentrations and temperatures. The conductivity studies were used to calculate change in enthalpy (∆Hom), change in entropy (∆Som) and change in Gibbs free Energy (∆Gom) of micellization. The interactions between quercetin and CTAB were found to be endothermic, entropically controlled and spontaneous. Further, ultrasonic sound velocity and density studies were carried out and utilized for the calculation of thermoacoustic parameters i.e. apparent molar volume and apparent molar compressibility. Thermoacoustic properties revealed that at higher surfactant concentration, hydrophobic interactions are dominant. The results suggested that the flavonoid-surfactant interactions in hydroethanolic solutions is more favourable as compared with aqueous solution. Overall, the data is favourable for the framework to be used for detailing advancement, drug development, drug industry, pharmaceutical industry, medical administration and formulation development studies.


1999 ◽  
Vol 28 (9) ◽  
pp. 929-930 ◽  
Author(s):  
Astushi Ikeda ◽  
Munenori Numata ◽  
Seiji Shinkai
Keyword(s):  

1991 ◽  
Vol 22 (3) ◽  
pp. 183-186 ◽  
Author(s):  
Diana C. W. Siew ◽  
Ralph P. Cooney ◽  
Michael J. Taylor

2011 ◽  
Vol 40 (12) ◽  
pp. 2072-2081 ◽  
Author(s):  
G. Astray ◽  
A. Cid ◽  
J. A. Manso ◽  
J. C. Mejuto ◽  
O. Moldes ◽  
...  

1987 ◽  
Vol 65 (5) ◽  
pp. 990-995 ◽  
Author(s):  
Gérald Perron ◽  
Josée Francoeur ◽  
Jacques E. Desnoyers ◽  
Jan C. T. Kwak

The apparent molar volumes and heat capacities of aqueous mixtures of neutral polymers and ionic surfactants were measured at 25 °C. The polymers chosen were poly(vinylpyrrolidone) (PVP) and poly(ethyleneoxide) (PEO) and the surfactants were the C8, C10, and C12 homologs of sodium alkylsulfates and the C10, C12, and C16 homologs of alkyltrimethylammonium bromides. The polymer–surfactant interactions depend on the nature of both components and on the chain length of the surfactant. The thermodynamic properties of the cationic surfactants are essentially the same in the absence and presence of polymer indicating little surfactant–polymer interaction. On the other hand, the thermodynamic properties of anionic surfactants are shifted, upon the addition of polymers, in the direction of enhanced hydrophobic association. The effect increases with the surfactant chain length and with the polymer concentration. The effect is larger with PVP than with PEO.


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