Self-Assembly and Rheological Properties of a Pseudogemini Surfactant Formed in a Salt-Free Catanionic Surfactant Mixture in Water

Abstract

The surface and bulk properties of bola-type dicarboxylic acid (sebacic acid, SA) and zwitterionic surfactant tetradecyldimethylamine oxide (C14DMAO) mixtures in aqueous solutions were studied. Surface tension measurements indicate a pronounced synergistic effect between SA and C14DMAO. In bulk aqueous solutions, rich phase behavior was observed with a varied SA-to-C14DMAO ratio (ρ) and a total surfactant concentration. Typically at ρ = 0.5, a novel pseudogemini surfactant (C14-S-C14) forms, driven by electrostatic interaction and hydrogen bonding. The C14-S-C14/H2O system exhibits rich phase behavior induced by the transition of aggregates. With increasing concentration of C14-S-C14, one can observe a viscous L1 phase, an L1/Lα two-phase region where a birefringent Lα phase is on the top of an L1 phase, a single Lα phase, and finally a mixture of an Lα phase and a precipitate. Microstructures formed in the Lα phases were determined by freeze-fracture transmission electron microscopy (FF-TEM) and cryogenic-transmission electron microscopy (cryo-TEM) observations. Polymorphic aggregation behavior was observed with the formation of a variety of bilayer structures including unilamellar vesicles, onions, and open and hyperbranched bilayers. Rheological measurements showed that the Lα phases are viscoelastic and sensitive to temperature where a quick loss of viscoelasticity was observed at elevated temperature.

Ubidecarenone-Loaded Nanostructured Lipid Carrier (UB-NLC): Percutaneous Penetration and Protective Effects Against Hydrogen Peroxide-Induced Oxidative Stress on HaCaT Cells

“…Freeze-fracture transmission electron microscopy (FF-TEM) was employed to characterize the morphology of UB-NLC [ 40 , 41 , 42 , 43 , 44 ]. For freeze-fracture (FF) measurements, droplets of the sample were dropped onto a specimen holder and frozen via a rapid plunge into liquid nitrogen.…”

Self-Assembled Vesicles Formed by Positional Isomers of Sodium Dodecyl Benzene Sulfonate-Based Pseudogemini Surfactants

“…However, the relatively complex and diverse molecular configurations made gemini surfactants difficult to synthesize, which limits their development and application. One promising strategy is to select “pseudogemini surfactants” that are constructed through noncovalent interactions (such as electrostatic interactions and π–π stacking) between “gemini-type” organic salts and monomeric surfactants. − Apparently, the pseudogemini surfactants fabricated by noncovalent interactions provide more selectivity and can effectively avoid complicated synthetic procedures.…”

A Thermally Stable Polyamine/Unsaturated Fatty Acid System: Gelation Behaviors and Application

“…However, these methods require complex chemical modifications and purification steps, which are quite costly. Unsaturated fatty acids can also be used simultaneously with metal hydroxides (Delample et al, 2011), calcium oxide, or organic bases (Horbaschek et al, 2000;Li et al, 2015;Zhou et al, 2014) to improve their solubility via neutralization. With protonated base as counterions, various types of self-assemblies can be obtained, including spherical micelles, wormlike micelles (Zhang et al, 2013), and bilayers/vesicles (Rasi et al, 2003) in diluted systems, liquid crystals or lamellae (Ouimet et al, 2003) in Supporting information Additional supporting information may be found online in the Supporting Information section at the end of the article.…”