Activity coefficient at infinite dilution of aqueous solutions of nonionic hydrocarbon and fluorocarbon surfactants as well as their ternary mixtures

Author(s):  
Katarzyna Szymczyka ◽  
Anna Tarabab

AbstractActivity coefficients at infinite dilution of the aqueous solutions of nonionic hydrocarbon surfactants, p-(1,1,3,3- tetramethylbutyl) phenoxypoly(ethylene glycols), Triton X-100 (TX100) and Triton X-165 (TX165), fluorocarbon surfactants, Zonyl FSN-100 (FSN100) and Zonyl FSO-100 (FSO100) and their ternary mixtures were determined from the Gracia-Fadrique et al. method for non-volatile compounds. The values of activity coefficients were calculated taking into account the surface tension data of the studied systems at 293K and compared to those determined on the basis of the values of the contact angle of solutions on the polytetrafluoroethylene (PTFE) and polymethyl methacrylate (PMMA) surfaces and the solid-liquid interface tension.

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4313
Author(s):  
Bronisław Jańczuk ◽  
Katarzyna Szymczyk ◽  
Anna Zdziennicka

Measurements were made of the surface tension of the aqueous solutions of p-(1,1,3,3-tetramethylbutyl) phenoxypoly(ethylene glycols) having 10 oxyethylene groups in the molecule (Triton X-100, TX100) and cetyltrimethylammonium bromide (CTAB) with Zonyl FSN-100 (FC6EO14, FC1) as well as with Zonyl FSO-100 (FC5EO10, FC2) ternary mixtures. The obtained results were compared to those provided by the Fainerman and Miller equation and to the values of the solution surface tension calculated, based on the contribution of a particular surfactant in the mixture to the reduction of water surface tension. The changes of the aqueous solution ternary surfactants mixture surface tension at the constant concentration of TX100 and CTAB mixture at which the water surface tension was reduced to 60 and 50 mN/m as a function of fluorocarbon surfactant concentration, were considered with regard to the composition of the mixed monolayer at the water-air interface. Next, this composition was applied for the calculation of the concentration of the particular surfactants in the monolayer using the Frumkin equation. On the other hand, the Gibbs surface excess concentration was determined only for the fluorocarbon surfactants. The tendency of the particular surfactants to adsorb at the water-air interface was discussed, based on the Gibbs standard free energy of adsorption which was determined using different methods. This energy was also deduced, based on the surfactant tail surface tension and tail-water interface tension.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Omer El-Amin Ahmed Adam ◽  
Ammar Hani Al-Dujaili ◽  
Akl M. Awwad

Densities of aqueous solutions of Ethylene glycol (EG), diethylene glycol (DEG), and triethylene glycol (TEG) were measured at temperatures from 293.15 to 318.15 K and molalities ranging from 0.0488 to 0.5288 mol·kg−1. Volumes of all investigated solutions at a definite temperature were linearly dependent on the solute molality; from this dependence the partial molar volumes at infinite dilution were determined for all solutes. It was found that the partial molar volumes at infinite dilution V-2,0 were concentration independent and slightly increase with increasing temperature. The partial molar volumes at infinite dilution V-2,0 or the limiting apparent molar volumes of ethylene glycols were fitted to a linear equation with the number of oxyethylene groups (n) in the solute molecule. From this equation a constant contribution of the terminal (OH) and the (CH2CH2O) groups to the volumetric properties was obtained. The thermal expansion coefficient (α1,2) for all investigated solutions was calculated at temperatures from 293.15 to 318.15 K. The thermal expansion coefficients for all solutes increase with increasing temperature and molality. Values of (α1,2) were higher than the value of the thermal expansion coefficient of the pure water.


Langmuir ◽  
2002 ◽  
Vol 18 (9) ◽  
pp. 3604-3608 ◽  
Author(s):  
J. Gracia-Fadrique ◽  
Pilar Brocos ◽  
Ángel Piñeiro ◽  
Alfredo Amigo

Author(s):  
H. Jeremy Cho ◽  
Vishnu Sresht ◽  
Daniel Blankschtein ◽  
Evelyn N. Wang

Heat transfer performance in pool boiling is largely dictated by bubble growth, departure, and number of nucleation sites. It is a well known phenomenon that adding surfactants can lower the liquid-vapor surface tension and increase the bubble departure frequency, thereby enhancing heat transfer. In addition to faster departure rates, surfactants are observed to dramatically increase the number of nucleation sites, which cannot be explained by simple surface tension arguments. Furthermore, it is not well understood which surfactant properties such as chemical composition and molecular structure affect boiling most significantly. From our experiments using Triton X-100 and Triton X-114 nonionic surfactants, we attribute boiling enhancement mainly to adsorption to the solid-liquid interface. Using the Mikic-Rohsenow model for boiling, a simple linear adsorption model, and the Cassie-Baxter description for contact angle, we developed a model that shows agreement with experimental results. This work offers some insights on how to predict boiling enhancement based on surfactant chemistry alone, which may aid in choosing optimal surfactants for boiling in the future.


2015 ◽  
Vol 3 (6) ◽  
pp. 1073-1082 ◽  
Author(s):  
Gonzalo Astray ◽  
◽  
Jorge Morales ◽  
Miriam González-Temes ◽  
Juan C. Mejuto ◽  
...  

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