ISSN:
1435-1536
Keywords:
Gelatin
;
ionic surfactants
;
adsorption
;
surface rheology
;
octadecanoic acid
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 rheological measurements of octandecanoic acid monolayers spread on gelatin solutions were performed. The interaction of the spread monolayer with the gelatin involves a strong rise of the solidity of the surface structure with distinct viscoelastic properties and is comparable with the experimental findings looking into the interaction between gelatin and an ionic surfactant. The results found by the addition of sodium-dodecylsulfate to the gelatin solution are discussed, assuming the formation of a multilayer consisting of octadecanoic acid molecules interacting to a negligible degree with the gelatin-surfactant complexes displaced from the surface. The surface rheological parameters are influenced by both layers in opposition to the dynamic behaviour at compression and dilation described in the first part of this paper. An analogous effect is found if the cationic hexadecyltrimethylammoniurn-bromide is added to the gelatin solution. The influence of CTAB is interpreted as the consequence of a steric hindrance, caused by the concentration of groups with opposite charges on the small polar ranges of the gelatin molecules. As a particular interaction of octadecanoic acid with the complexes is possible, a mixed adsorption layer is formed and the high solidity of the surface layer is prevented by the presence of molecules not interacting with the complexes.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01422862
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