Synthesis, Characterization, Antibacterial Activity, and Interfacial and Micellar Features of Novel Cationic Gemini Surfactants with Different Spacers

Abstract

In the present study, four novel imidazolium‐based cationic gemini surfactants (IBCGS) have been synthesized, having same hydrocarbon chain lengths and different spacers. The impacts of type and nature of spacer on Krafft temperatures (TK) have been examined. Micellization behaviors of IBCGS have been investigated at different temperatures above TK by both surface tension and specific conductivity measurements. Surface activity properties of aqueous systems have been calculated using the results of the measurement data. Critical micelle concentration (CMC), surface pressure at CMC (ПCMC), minimum area of head group (Amin), degree of counterion binding (β), degree of counterion dissociation (α), and maximum surface excess (Γmax) of IBCGS have been calculated with data of surface tension and specific conductivity. IBCGS have low CMC values than other imidazole categories of gemini and monomeric cationic surfactants. Micelle aggregation number (Nagg) values have been determined with the steady‐state fluorescence quenching method. The values of Nagg have been found in the range of 19–28. Additionally, the antibacterial activities of IBCGS on gram‐positive and gram‐negative bacteria have been investigated. IBCGS studied in this article have showed perfect antibacterial activity particularly against gram‐positive bacteria. The data obtained in this study may be benefical for the surfactant applications in different areas.

Impact of the Hydrocarbon Chain Length of Biodegradable Ester-Bonded Cationic Gemini Surfactants on Self-Assembly, In Vitro Gene Transfection, Cytotoxicity, and Antimicrobial Activity

“…coli and S. aureus. , When compared to Gemini with comparable alkyl chain length and spacer, the MIC values of the investigated Gemini were found to be much lower, indicating better antibacterial activity of the ester boned Gemini. − Furthermore, the values are smaller than those of kanamycin (82.5 μM) against E. coli and ampicillin (0.7 μM) against S.…”

Effect of Spacer Structures on the Interfacial Adsorption and Micelle Properties of Quaternary Ammonium Salt-Based Gemini Surfactants

“…Clear aqueous solutions of quaternary ammonium salt-based gemini surfactants (0.0050–0.20 wt %) were prepared and placed in a refrigerator at ∼5 °C for at least 24 h. As the solutions were clear with no visible precipitates, the T K value was estimated to be <5 °C. As the gemini surfactants precipitated out from the solutions, the temperature of the cooled surfactant solutions was raised gradually under constant stirring, and the conductance (κ) was measured by raising the temperature from 0.5 to 5.0 °C. ,, The conductivity of the surfactant solution increased with increasing temperature due to dissolution of the surfactants. The conductivity increased gradually above a certain temperature.…”

“…It is interesting that the chain lengths and spacer characteristics of gemini surfactants affect their adsorption properties at the air/water interface and micellar properties in aqueous solutions. There have been many reports of gemini surfactants with different spacer structures. − However, there are a relatively few reports on the structures of gemini surfactants that focus on the changes in their properties caused by changing the spacer structures, which were cyclic structures such as diethylene and triethylene chains instead of benzene ring and amino group instead of the amide group.…”

Fabrication of Encapsulated Gemini Surfactants

“…From an ecological point of view, the functionalization of substituents with groups of natural origin is of great importance, because it can increase their biological profile, improving biodegradability or reducing ecotoxicity [ 8 , 38 ]. Gemini surfactants are referred to as multifunctional, because one compound may be an exceptionally effective surface active agent [ 39 , 40 , 41 ], corrosion and biocorrosion inhibitor [ 42 , 43 , 44 , 45 , 46 , 47 ], but also has remarkably high antibacterial [ 48 , 49 , 50 , 51 ] and antifungal [ 52 , 53 , 54 , 55 , 56 , 57 ] activity and is effective in preventing biofilm eradication [ 52 , 58 ]. It is worth emphasizing that gemini surfactants work effectively at a very low concentration, often several times smaller in comparison to single quaternary ammonium salts [ 59 , 60 , 61 , 62 , 63 ].…”