Tensiometric and Rheological Properties of Functionalized Imidazolium Surfactants at a Liquid–Gas Interface

Applications of Molecular Structural Aspects of Gemini Surfactants in Reducing Nanoparticle–Nanoparticle Interactions

“…The shift in the maximum toward lower mole ratios of intensity (Figure a) and WL (Figure b) suggests a delay in the onset of NP–NP interactions by increasing hydrophobicity (from C12 to C16), which also significantly increases the size (up to ∼2000 nm) of the NP–NP complex, which is even much greater than that produced by 16-2-16 (∼700 nm) previously observed in Figure c. This indicates that the induction of the imidazolium head group is also responsible for the reduction of electrostatic interactions due to the presence of aromaticity in the head group region in comparison to the tetraalkylammonium head group of 16-2-16, which in turn promotes the hydrophobic interactions. − This is evident from an increase in the size with the increase in the hydrocarbon chain length, which clearly indicates the participation of the hydrophobic interactions in NP–NP complexation. Thus, the increase in the size of the NP–NP complex happens only when the length of the hydrocarbon tail of the gemini surfactant is increased, which is in contrast to the increase in the spacer length that actually decreases the size and produces smaller stable colloidal aggregates (Figure c).…”