Sodium Bromide Induced Micelle to Vesicle Transitions of Newly Synthesized Anionic Surface Active Ionic Liquids Based on Dodecylbenzenesulfonate

Abstract

Dodecylbenezenesulfonate-based anionic surface active ionic liquids (DBS-ILs) paired with onium cations, n-butyltrimethylammonium ([N1114]), 1-butyl-3-methylimidazolium ([C4mim]), and N-butylpyridinium ([C4Py]) have been synthesized. DBS-ILs were found to be highly surface active having critical micelle concentration (CMC) lower than that of their conventional analogue sodium dodecylbenezenesulfonate ([Na][DBS]). The CMC values of DBS-ILs were determined from surface tension (ST) and isothermal titration calorimetry (ITC). DBS-ILs formed micelles predominantly in the aqueous medium, and unlike [Na]DBS, the micelles of DBS-ILs could be transformed into vesicles with the addition of sodium bromide (NaBr). Micelle to vesicle transitions (MVTs) were evidenced from dynamic light scattering (DLS), turbidity, proton nuclear magnetic resonance ((1)H NMR), and cryo-TEM techniques. Thermodynamics of aggregation was investigated from ITC which indicated that the aggregation process is primarily driven by the entropy factor. The formation of a vesicle upon addition of NaBr has been accounted to the increased electrostatic interactions between the less hydrated sulfonate headgroup and the more populated bigger sized counterions along with the favored cation-π or π-π interactions between them as evidenced from 2D-NOESY NMR experiments. The stimuli-responsive morphological transitions in the self-assembly of the reported anionic surface active ionic liquids (SAILs) will be useful for encapsulation and delivery of active (bio)molecules in the targeted biomedical applications.

Physico‐chemical and Spectroscopic Approach to Analyse the Behaviour of Surface‐Active Ionic Liquid and Conventional Surfactant in Aqueous Glycine

“…In recent years, ionic liquids (IL) with long alkyl chains and the combined/desired properties of surfactants, termed surface active ionic liquids (SAIL), have attained considerable interest of chemists for use as novel surfactants [1,2]. Because of their inherent greenness and amphiphilicity, SAIL are promising substitutes for conventional surfactants in applications such as nanoparticle synthesis, micellar catalysis, solubilisation, protein folding, in vivo transfection activity of genes into cells, and drug release [3][4][5][6][7][8]. Thus, working with SAIL has become a fascinating area for researchers.…”

5-Methyl Salicylic Acid-Induced Thermo Responsive Reversible Transition in Surface Active Ionic Liquid Assemblies: A Spectroscopic Approach

“…[9][10][11][12] In aqueous solution, the transition from micelle to vesicle is commonly influenced by various external stimuli; therefore this has been executed by variation in the ratio of cationic and anionic surfactants, polar additives, temperature, salts etc. [13][14][15][16][17][18][19][20][21] The morphology of the aggregates sometimes depends on the nature of additives. 14,[22][23][24][25] Considering the influence of organic additive in aggregate transition, we have been motivated to study micelle-elongated micelle-vesicle transition using room temperature ionic liquids as amphiphiles.…”

Ionic Liquids Derived from Proline: Application as Surfactants

“…Knowing the high stability of ILs derived from dodecylbenzenesulfonate anion [DBS], the IL [ i C 4 Pro][DBS] ( 10 ) was synthesized by treatment of the corresponding chloride [ i C 4 Pro] Cl ( 3 ) with sodium dodecyl benzenesulfonate (Scheme ). Its structure, no previously reported in literature, was confirmed by 1 H and 13 C NMR spectroscopy as well as HRMS spectrometry (see Supporting Information).…”