Surface properties of N‐alkanoyl‐N‐methyl glucamines and related materials

Abstract

The surface properties [effectiveness of surface tension reduction (γ CMC ), critical micelle concentration (CMC), efficiency of surface tension reduction (pC 20 ), maximal surface excess concentration (Γ max ), minimal area/molecule at the interface (A min ), and the (CMC/C 20 ) ratio] of some well-purified N-alkanoyl-N-methyl glucamines and related polyol-based Nmethyl amide-type surfactants, having the structural formula RC(O)N(Me)CH 2 (CHOH) x CH 2 OH, where RC(O) = undecanoyl, lauroyl, tridecanoyl, myristoyl, and x = 1, 3, and 4, were investigated at 25°C in distilled water and 0.1 M NaCl. Water solubility of these compounds does not simply depend on the number of hydroxyl groups in the molecule but is associated with the balance between intermolecular hydrogen bonds and hydrogen bonds formed with water molecules. The fundamental interfacial properties, such as CMC and γ CMC , and two thermodynamic parameters, standard free energy of adsorption and standard free energy of micellization, were found to be significantly dependent on the hydrophobic acyl chain rather than on the number of CHOH groups in the hydrophilic moieties. By contrast, the practical performance properties were greatly dependent on the nature of the hydrophilic group. As a whole, these surfactants had desirable foaming properties and efficient wetting abilities. Furthermore, synergism in foaming and wetting abilities was observed in a binary mixture of these surfactants with an alkyloxyethylene sulfate.

Preparation and properties of new lactose‐based surfactants

“…This observation confirms a reported common feature of so-called sugar surfactants (6,8,11,13,14,16). As indicated by the Krafft temperature values (Table 2) , the surface excess concentration Γ CMC was calculated from the Gibbs adsorption isotherm.…”

“…The values are in the range from about 49.4 × 10 −20 to 50.8 × 10 −20 m 2 . They are lower than those reported for oxyethylene-based nonionic surfactants (23,24) but higher than those obtained by Zhu et al (11) for N-alkanoyl-N-methyl glucanamines. This difference may arise from different hydration by water molecules of the oligooxyethylene chain in comparison to hydroxyl groups of the lactose-derived moiety.…”

“…The results obtained are summarized in Table 2, which includes the following adsorption parameters: γ CMC (the effectiveness of surface tension reduction), pC 20 (the efficiency of surface adsorption-the negative log of the bulk surfactant concentration C 20 required to reduce the surface tension of the solvent by 20 mN/m), and CMC/C 20 ratio [a measure of the tendency of the surfactant to adsorb at the aqueous/air interface relative to its tendency to form micelles in the bulk surfactant solution (23)] both for the studied N-alkanoyl-N-methyllactitolamine surfactants and other related surfactants described in the literature, such as N-dodecanoyl-N-methyl glucamines (11) or N-alkyl-Nmethyllactobionamides (8,12).…”

“…Because of these valuable features, many research groups have directed their studies to various aspects of synthetic methodologies and properties of a wide range of saccharide surfactants that vary in their molecular architecture, such as single-chain, single-head entities (5)(6)(7)(8)(9)(10)(11)(12), di-chained (13,14) and dicephalic compounds (15,16) as well as bolaamphiphiles and gemini structures (17,18). Accordingly, all of these saccharide-derived materials exhibit similar general trends in surface-active behavior as reported for polyoxyethylene-based nonionics.…”

Mixtures of Nonionic Surfactants Made from Renewable Resources with Alkyl Sulfates: Comparison of Headgroups

“…Two common surfactants made from renewable resources are the sugar-based alkyl N-methyl glucamines and alkyl glucopyranosides (glycosides) [1,2]. N-Methyl glucamines (MEGAs) are interesting surfactants that show promising properties and good interaction with sodium dodecyl sulfate [3][4][5][6]. They are rather inexpensive and easy to find in a range of alkyl chain lengths, so this type of surfactant was used in this study.…”