Wormlike micelles formed using Gemini surfactants with quaternary hydroxyethyl methylammonium headgroups

Abstract

The aggregation behavior of Gemini surfactants with hydroxyl groups in their headgroups, butane-1,4-bis(hydroxyethyl methylalkylammonium) bromides hereafter abbreviated as m-4-m MEA (m = 12, 14, 16), has been investigated in aqueous solution. Each formed a viscous fluid in water at low concentration in the absence of a salt. In solutions of 14-4-14 MEA, the formation of highly viscoelastic wormlike micelles could be detected using steady and dynamic rheological measurements. The existence of these long column micelles has also been confirmed using cryo-transmission electron microscopy (cryo-TEM) and small angle X-ray scattering (SAXS). Compared with conventional bis(dimethylalkylammonium) bromide Gemini molecules with the same spacer (14-4-14), 14-4-14 MEA demonstrated a better ability to fabricate wormlike micelles because of the change in the headgroup structure. As for 16-4-16 MEA, which has longer alkyl chains, its aqueous solutions behave more like elastic gels at a concentration of 80 mmol L(−1). The unique viscoelastic behavior of m-4-m MEA in water can be attributed to the synergistic interactions of hydrophobic attraction and hydrogen bonding. The obtained results are believed to be an important addition to the effect that the headgroups of Gemini surfactants have on their aggregation behavior in dilute solutions.

Solvent-dependent nanostructures of gels of a Gemini surfactant based on perylene diimide spacer and oligostyrene tails

“…Gemini surfactants have attracted significant research efforts in the past couple of decades due to their enhanced properties (such as low CMC) compared to conventional single-chained amphiphils [1][2][3][4][5][6][7][8][9][10][11][12][13]. These are simply two charge centers (usually cationic), attached to hydrocarbon tails, and separated by a spacer: the sequence consists of a hydrocarbon tail, an ionic group, a spacer, an ionic group and a hydrocarbon tail [1][2][3].…”

Phase Behavior and Aggregation in a Catanionic System Dominated by an Anionic Surfactant Containing a Large Rigid Group

“…As Figure a shows, the viscosities of all the samples show a Newtonian plateau at low shear rates followed by shear thinning as the shear rate attains a certain value. This is the typical steady shear behavior of worm‐like micelles and characterizes the construction of worm‐like micelles . The C 12 ‐MPA‐Na/CTAB and C 16 ‐MPA‐Na/CTAB systems show similar results (see Figure S3 in the Supporting Information).…”

“…This is the typicals teady shear behavioro f worm-like micelles and characterizest he construction of worm-like micelles. [31][32][33] TheC 12 -MPA-Na/CTAB and C 16 -MPA-Na/ CTAB systemss how similarr esults( see Figure S3 in the Supporting Information). In accordance with the Carreau model, [17,19] the zero-shear viscosity (h 0 )c ould be obtained by extrapolating viscosity to the zero-shear rate in the viscosity versus the shear rate curve, and the resultsa re exhibitedi n Figure 2b.…”

Application of pH‐Responsive Viscoelastic Surfactant as Recyclable Fluid at High Temperature

“…Hence, aqueous surfactant solutions that can form wormlike micelles are usually labeled as “living polymer solution” (Dai et al, ; Lin et al, ). Many studies focused on the similarities and differences between wormlike micelle and conventional polymer in aqueous solution (Jessop et al, ; Li et al, ; Morita et al, ). Although polymer is held by strong covalent bonds that are not easy to break, the polymer chain cannot be recovered after shear breaking; while wormlike micelle is held by weak physical bonds that can continuously break and re‐form; thus, the wormlike micelle can be quickly recovered after it was broken.…”

“…Hydrotropes were well‐known substances that can promote the growth of smart wormlike micelles in surfactant aqueous solution, and in which molecules interact with hydrotropes due to electrostatic repulsion and synergistic effects (Li et al, ; Wu et al, ). Thus, hydrotropes were also an effective way to enhance the viscoelasticity of VES fluids that formed by smart wormlike micelles.…”