Dynamic Percolation and Swollen Behavior of Nanodroplets in 1-Ethyl-3-methylimidazolium Trifluoromethanesulfonate/Triton X-100/Cyclohexane Microemulsions

Abstract

Microemulsions comprising an ionic liquid (IL), 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ([emim][OTf]), as the polar component, Triton X-100 as a surfactant, and cyclohexane as the nonpolar medium were prepared and characterized. Conductivity and dynamic viscosity data were critically analyzed to confirm dynamic percolation among the droplets that are in continuous motion, aggregation, and fission. The transition from oil-continuous phase to bicontinuous phase was observed at the conductance and viscosity percolation thresholds and sharp changes in the values of conductivity and dynamic viscosity could be identified. Dynamic light scattering measurements revealed swelling of the droplets, which varied within the hydrodynamic diameter range of 10-100 nm. Diffusivity of the droplets suggested less Brownian movement with increased amount of the IL. Moreover, changes in the droplet sizes and diffusivity with increase in IL content supported dynamic percolation within the systems.

Nonaqueous Microemulsion in the Bmim Tf2N/Brij 30/n-Nonane System: Structural Investigation and Application as Gold Nanoparticle Microreactor

“…As the Brij 30 content increases, a percolation behavior is observed toward the formation of a bicontinuous microemulsion. These results are consistent with other reports in which nonaqueous microemulsions, discrete and bicontinuous, are described in the presence of a fluorinated IL stabilized by a nonionic surfactant in oil. − …”

“…Although the most investigated nonionic surfactant in these systems appears to be Triton X-100, − for this work we selected the polyoxyethylated lauryl ether [Brij 30, linear formula: C 12 H 25 (OCH 2 CH 2 ) 4 OH] and we explored the phase diagram for the Bmim Tf 2 N/Brij 30/ n -nonane system at 25 °C (see Figure ). Samples in the microemulsion region were prepared and characterized by means of dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS).…”

Encapsulation of Antibiotic Levofloxacin in Biocompatible Microemulsion Formulation: Insights from Microstructure Analysis

“…On the contrary, the σ showed a sharp decrease in its values with more water content above Φ b (Φ w > 30.0%), which suggested the phase transition, forming o/w μE. , These phase transitions in μE microdomains were further explored by means of dσ/dΦ with Φ w increment, as shown in Figure . A maximum in the first derivative (dσ/dΦ) of σ is observed at Φ w of ∼24.0%, reflecting on the existence of bicontinuous microstructure in this region. − …”

Fourth-Generation Antibiotic Gatifloxacin Encapsulated by Microemulsions: Structural and Probing Dynamics

“…At Φ w ∼ 20%, the maximum first derivative value is observed, indicating the existence of a stable bicontinuous microstructure in this particular region. For μE-B, the corresponding values of Φ w for all suggested transitions in the microstructure are the percolation threshold (Φ p ∼ 5%), phase inversion (Φ b ∼ 9%), and bicontinuous channel (dσ/dΦ ∼ 7%). ,,− …”