ISSN:
1435-1536
Keywords:
2-alkyl-2-methyl-1,3-dioxolanes
;
2-alkyl-4-methyl-1,3-dioxolanes
;
2-alkyl-1,3-dioxanes
;
surface tension isotherms
;
standard free energy of adsorption
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Surface tension measurements on aqueous solutions of 2-alkyl-2-methyl-1,3-dioxolanes, 2-alkyl-4-methyl-1,3-dioxolanes, and 2-alkyl-1,3-dioxanes at a temperature of 293.2 K are presented. The surface tension isotherms obtained were used to calculate some adsorption parameters, i. e. the efficiency of surface tension reduction, pC25, surface excess concentration, Γ, and surface area,A, per molecule in the adsorption layer. The Temkin adsorption isotherm equation was used to calculate standard free energy of adsorption,Δ G 0 θ=0.5 . The increments for a methylene group in the alkyl chain,Δ G o [−CH2−], and for the residual part of the molecule,Δ G o [W], were also determined. The results obtained show that: (i) an increase in alkyl chain length at the C-2 carbon atom of the ring by one methylene unit brings about a marked increase in surface activity; (ii) the introduction of a methyl group into the 1,3-dioxolane ring (i. e., at C-2 or C-4 atom) has a weaker effect on surface activity of alkyl-substituted 1,3-dioxolanes, and (iii) the contribution of the 5- and 6-membered 1,3-dioxacyclane rings to a total surface activity of, respectively, 2-alkyl-1,3-dioxolanes and 2-alkyl-1,3-dioxanes is similar.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01410993
Permalink
