Effect of cationic head group on micellization behavior of new amide-functionalized surface active ionic liquids

Abstract

Amide-functionalized surface active ionic liquids (SAILs), 1-methyl-1-dodecyl piperidinium chloride, [C12APip][Cl]; 1-methyl-1-dodecyl pyrrolidinium chloride, [C12APyrr][Cl]; 1-methyl-3-dodecyl imidazolium chloride, [C12Amim][Cl], and 1-methyl-1-dodecyl morpholinium chloride, [C12AMorph][Cl], have been synthesized, characterized and investigated for thermal stability, and micellization behavior in aqueous medium. The introduction of an amide moiety in the alkyl chain decreased the thermal stability of the functionalized SAILs compared to non-functionalized SAILs bearing a simple alkyl chain. A variety of state of the art techniques, viz. tensiometry, conductometry, steady-state fluorescence, isothermal titration calorimetry (ITC), dynamic light scattering (DLS) and atomic force microscopy (AFM), have been employed to investigate the micellization behavior. Amide-functionalized SAILs have shown much lower critical micelle concentration, cmc, and better surface active properties as compared to homologous non-functionalized SAILs. Steady-state fluorescence has provided information about cmc, aggregation number (Nagg) and polarity of the cybotactic region of the micelles, whereas ITC has provided insights into the thermodynamics of micellization. Furthermore, the size and shape of the micelles have been investigated using DLS and AFM techniques.

New ester based gemini surfactants: the effect of different cationic headgroups on micellization properties and viscosity of aqueous micellar solution

“…The fluorescence spectrum of pyrene in water exhibits five predominant peaks and the ratio of intensity of the first (I 1 at 373 nm) and third peaks (I 3 at 384 nm) is sensitive to the probe's environment. 43 This may be attributed to the presence of the polar ester functionality as spacers since similar behavior has been observed for other ester functionalized gemini surfactants. I 1 /I 3 is almost constant if no micellar aggregate is present in the solution since the fluorescence probe is completely exposed in the solution, however as the interface becomes completely occupied by the surfactant monomers the surfactant molecules start aggregating as micelles and this causes sigmoidal drop in the I 1 /I 3 intensity.…”

Aqueous colloidal systems of bovine serum albumin and functionalized surface active ionic liquids for material transport

“…It is problematic to describe and quantify precisely the types of processes 40,[62][63][64][65] occurring during complexation, therefore qualitative information has been derived from the obtained thermodynamic data. For all the investigated SAIL-BSA systems, in dilute solution, DH is endothermic as compared to corresponding aqueous SAILs (Fig.…”

Effect of amino acid addition on the micelle formation of the surface‐active ionic liquid 1‐tetradecyl‐3‐methylimidazolium bromide in aqueous solution

“…For example, only [C n mim]Cl with n >8 form aggregates in solution and when Cl − is replaced by [NTf 2 ] − or [PF 6 ] − anions; no micelle formation is observed . Moreover, other types of SAILs with varied cations rings, such as alkylpyridinium ([C n Py] + ), alkylmethylpyrrolidinium ([C n mPyrr] + ), alkylmethylpiperidinium ([C n mpip] + ), and morpholinium ([C n Morph] + ), have been reported …”

“…[15] Moreover, other types of SAILs with varied cations rings, such as alkylpyridinium ([C n Py] + ), alkylmethylpyrrolidinium ([C n mPyrr] + ), alkylmethylpiperidinium ([C n mpip] + ), and morpholinium ([C n Morph] + ), have been reported. [19][20][21][22] . In addition, other parameters such as temperature and the presence of inorganic or organic additive exert a significant effect on the self-aggregation behavior of a number of surfactants.…”