A Spin-Probe Study of the Modification of the Hydration of SDS Micelles by Insertion of Sugar-Based Nonionic Surfactant Molecules

Abstract

The spin-probe detected polarity index H(25 °C) of SDS micelles decreases linearly with the number of inserted sugar-based nonionic surfactant molecules. This decrease is interpreted as being due to the expulsion of water molecules by the sugar groups from the polar shell surrounding the hydrocarbon core of the dodecyl micelle. Employing the geometrical model described in the companion paper immediately preceding this work, the effective volume of water expulsion is found to be similar to the volume of the sugar groups after taking into account that the OH bonds of the sugar groups also contribute to the polarity index H(25 °C). The estimate of the hydration of pure SDS micelles as a function of their aggregation number from these studies with the spin probe 16 doxylstearic acid methyl ester is similar to that with 5 doxylstearic acid methyl ester. This confirms that both spin probes are located similarly in the polar shell.

Biocompatible microemulsions of dicephalic aldonamide-type surfactants: Formulation, structure and temperature influence

“…It is perhaps due to the steric hindrance of doubled hydrophilic gluconyl groups and the hydrogen bonding between them. These results are in agreement with earlier obtained data for micelles formed by single-head single-tail, dicephalic and gemini saccharide surfactants [59] as well as with those obtained by Bales et al for SDS micelles modified with nonionic double-headed sugar surfactant [35,60]. As anticipated, the 16-DSE correlation time s R , which monitors the surfactant chains mobility, displays significant temperature dependence.…”

“…Fortunately, they can be obtained in a straightforward three-step procedure from readily available, inexpensive reagents. In the literature only Bales et al [35] performed microenvironment characteristics of micelles of double-headed dodecyl-malono-bis-Nmethylglucamide in the mixture with SDS.…”

EPR Line Shifts and Line Shape Changes Due to Spin Exchange of Nitroxide Free Radicals in Liquids 2. Extension to High Spin Exchange Frequencies and Inhomogeneously Broadened Spectra

“…Assuming ideal mixing as a first order approximation, it is easily shown that the change in H in going from zero to 52 mM 16DSE is approximately 8 × 10 -3 . From previous work(eq 12 of ref 4), it is known that this change in H corresponds to a change in the nitrogen hyperfine coupling constant of approximately 11 mG, or a change in A abs /A 0 of about 8 × 10 -4 . This is the maximum effect anticipated for the most concentrated sample and corresponds only to about twice the size of the symbols in Figure 10 and is therefore a negligible effect.…”

Synthesis and Properties of 1,1‐bis{[3‐(N,N‐Dimethylamino)propyl]amido}alkane‐di‐N‐oxides

“…Surface active N-alkyl-bisglucamides were patented by Pitt et al [13]. The last-mentioned surfactants were then intensively investigated in mixtures with SDS, gelatin, and polymers [14][15][16][17][18][19]. Surface active, nontoxic, and biodegradable double-headed amides derived from aldo(bio)N lactones or acids and N-alkyl-N,N-bis(3-aminopropyl)amines were synthesized and investigated by Wilk et al [20,21].…”