Experimental and Theoretical Approach to Nonequivalent Adsorption of Novel Dicephalic Ammonium Surfactants at the Air/Solution Interface

Abstract

The interfacial behavior of novel dicephalic cationic surfactants, N,N-bis[3,3'-(trimethylammonio)propyl]alkylamide dibromides and N,N-bis[3,3'-(trimethylammonio)propyl]alkylamide dimethylsulfates, was analyzed both experimentally and theoretically in comparison to their linear standards, 3-[(trimethylammonio)propyl]dodecanamide bromide and 3-[(trimethylammonio)propyl]dodecanamide methylsulfate. Adsorption of the studied double head-single tail surfactants depends strongly upon their structure, making them less surface active in comparison to the single head-single tail structures having the same alkyl chain length. Surface tension isotherms of aqueous solutions of the studied dicephalic derivatives were measured using the pendant drop shape analysis method and interpreted with the so-called surface quasi-two-dimensional electrolyte (STDE) model of ionic surfactant adsorption. The model is based on the assumption that the surfactant ions and counterions (bromide and methylsulfate ions in the studied case) undergo nonequivalent adsorption within the Stern layer, and it allows for accounting for the formation of surfactant ion-counterion associates in the case of multivalent surfactant headgroup ions. As a result, good agreement between theory and experiment was obtained. Additionally, the presence of surfactant-counterion complexes was successfully confirmed by both measurements of the concentration of free bromide ions in solution and molecular modeling simulations. The results of the present study may prove useful in the potential application of the investigated dicephalic cationic surfactants.

Nanoemulsion-templated multilayer nanocapsules for cyanine-type photosensitizer delivery to human breast carcinoma cells

“…Cyanine-type photosensitiser: IR-786 iodide, human serum albumin (HSA), as well as polyelectrolytes of opposite charges: polyanion-polysodium 4-styrenesulphonate (PSS, Mw 70 kDa), and polycation -poly(diallyldimethyl-ammonium) chloride (PDADMAC, Mw 100-200 kDa), were obtained from Sigma-Aldrich. Surfactants: 2-(dodecyldimethylammonio)-ethylglucoheptonamide bromide (D 2 GHA-12), and N,N-bis[3,3 0 -(trimethylammonio)propyl]dodecanamide dimethylsulfate (C 12 (TAPAMS) 2 ) were synthesized according to the method described in (Skrzela et al, 2010;Zak and Conner, 1974;Wilk et al, 2009). N-dodecane (ND, Fluka) and oleic acid (OA, POCH, Poland) were used as the oil phases.…”

Biofilm prevention by dicephalic cationic surfactants and their interactions with DNA

“…good surface activity and ability to aggregate, strong interactions with a variety of polyelectrolytes, lower impact on the environment and antistatic action (Skrzela et al . ; Frąckowiak et al . ; Piętka‐Ottlik et al .…”

Synthesis, surface activity and antielectrostatic properties of new soft dichain cationic surfactants

“…A c c e p t e d M a n u s c r i p t As a continuation of our studies on new functionalized cationic surfactants and their properties [15][16][17][18], herein we describe synthetic methodology, surface activity and antielectrostatic properties, regarding the structure-performance relationships, of two homologous series of new soft cationic surfactants, diesterquat-type N, N-dimethyl-N,N-bis[2-(alkyloxycarbonyl)ethyl]ammonium bromides (2xC n E-Br, n = 10, 12) and diamidequat-type N, N-dimethyl-N,N-bis[2-(N-alkylcarbamoyl)ethyl]ammonium bromides (2xC n A-Br, n = 8, 10, 12) surfactants (all structures and the applied synthetic route are shown in Scheme 1).…”

“…Studies on interfacial properties of cationic surfactants are very important for many practical applications related to their solubilization ability, adsorption and aggregation properties, improvement of wetting and antimicrobial activity against bacteria, yeasts and molds [2,7,9,[11][12][13][14]. Nowadays, functionalized cationic surfactants are also used as protective materials on the surfaces of solids, lubricants, antistatic agents and fabric softeners because they adsorb onto textiles due to their negative-charged surfaces in water [10,11].A c c e p t e d M a n u s c r i p t As a continuation of our studies on new functionalized cationic surfactants and their properties [15][16][17][18], herein we describe synthetic methodology, surface activity and antielectrostatic properties, regarding the structure-performance relationships, of two homologous series of new soft cationic surfactants, diesterquat-type N, N-dimethyl-N,N-bis[2-(alkyloxycarbonyl)ethyl]ammonium bromides (2xC n E-Br, n = 10, 12) and diamidequat-type N, N-dimethyl-N,N-bis[2-(N-alkylcarbamoyl)ethyl]ammonium bromides (2xC n A-Br, n = 8, 10, 12) surfactants (all structures and the applied synthetic route are shown in Scheme 1).Common characteristics of obtained series of compounds is the presence of labile linkers -ester -COOR or amide -CONHR moieties -between the alkyl tails and the hydrophilic quaternary ammonium group. Both groups are vulnerable to hydrolytic degradation in acidic and basic aqueous media.…”