Micellar properties of nonionic saccharide surfactants with amide linkage in aqueous solution

Synthesis and Surface Properties of N-Alkyl-N-methylgluconamides and N-Alkyl-N-methyllactobionamides

“…These results seem to be reasonable, taking into account that the character of the lactobionic is more hydrophilic than that of the gluconic group. Arai et al (16) reported the CMC for the N -dodecyllactobionamide to be 1.8 × 10 −4 mol dm −3 , which is lower than that obtained for C12-MLA in this study. This is consistent with other observations on the effect of N -methyl grouping present in alkylaldonamides upon their hydrophilic character (15,33).…”

“…The surface area demand per molecule, A min , does not change substantially in both investigated series of surfactants. The values are in the range of about 40 × 10 −20 to 44 × 10 −20 m 2 and are similar to those obtained by Zhang and Marchant (19) for N -alkylmaltobionamides and by Arai et al (16) for N -alkyllactobionamides. However, they are lower than those reported for polyoxyethylene-based nonionic surfactants (31,32).…”

“…This phenomenon was discussed by Okawuchi et al (33), who investigated surface properties of N -alkanoyl-N -methylgluconamides. It is accepted by the authors (16,19,33,34) that the size of the saccharide moiety is a determining factor in surface area occupied by surfactants at the waterair interface. However, our results seem to suggest that both the Cn-MGA, e.g., gluconamides with open-chain structure, and Cn-MLA, e.g., lactobionamides containing one glucopyranoside ring and one open-chain glucose unit, occupy nearly the same surface area per molecule at the interface showing that the alkyl chains in both series are similarly packed at the (9), who compared the A min value for N -decanoyl-N -methylglucamide with that for octyl-β-glucopyranoside at 25…”

“…Recently, gel-forming properties (9-13), formation of mono-and bilayers (8,10,12), formation and structure of microemulsion systems containing N -alkylamides (14), as well as aggregation behavior of diastereomeric and enantiomeric Noctylaldonamides (10) have been investigated. Several papers reported on surface-active properties of aqueous solutions of N -alkylgluconamides (9,15), N -alkyllactobionamides (16,17), and N -alkylmaltobionamides (18,19), characterized by surface tension measurements. Furthermore, the syntheses and surface properties of aldonamides containing an acetal function, i.e., a 1,3-dioxane ring (20), as well as aldonamides with more than one hydrophobic and/or saccharide hydrophilic groups (21)(22)(23)(24)(25) have been reported, some of them representing bolaform amphiphiles (21).…”

Novos tensoativos derivados da 2-D-glucosamina

“…Gráfico 27 -Gráficos de Debye para os tensoativos catiônicos, em solução aquosa com 0,1 mol/L de NaCl, a 25°C. A dodecil-lactobionamida, por exemplo, possui número de agregação de 178 e raio hidrodinâmico de 7 nm, em solução aquosa a 40°C (ARAI et al, 1996). As hexadecanoilamidas derivadas da maltose e da maltotriose apresentam agregados ainda maiores em solução aquosa (raios hidrodinâmicos de 25 nm a 66 nm), provavelmente na forma de bastões (DENKINGER et al, 1989).…”