Widely Adaptable Oil‐in‐Water Gel Emulsions Stabilized by an Amphiphilic Hydrogelator Derived from Dehydroabietic Acid

Abstract

A surfactant, R‐6‐AO, derived from dehydroabietic acid has been synthesized. It behaves as a highly efficient low‐molecular‐weight hydrogelator with an extremely low critical gelation concentration (CGC) of 0.18 wt % (4 mm). R‐6‐AO not only stabilizes oil‐in‐water (O/W) emulsions at concentrations above its critical micelle concentration (cmc) of 0.6 mm, but also forms gel emulsions at concentrations beyond the CGC with the oil volume fraction freely adjustable between 2 % and 95 %. Cryo‐TEM images reveal that R‐6‐AO molecules self‐assemble into left‐handed helical fibers with cross‐sectional diameters of about 10 nm in pure water, which can be turned to very stable hydrogels at concentrations above the CGC. The gel emulsions stabilized by R‐6‐AO can be prepared with different oils (n‐dodecane, n‐decane, n‐octane, soybean oil, olive oil, tricaprylin) owing to the tricyclic diterpene hydrophobic structure in their molecules that enables them to adopt a unique arrangement in the fibers.

CO2-Responsive Rosin-Based Supramolecular Hydrogels: Diverse Chiral Nanostructures and Their Application in In Situ Synthesis of Chiral Gold Nanoparticles

“…21−25 In addition, a rigid rosin skeleton contains multiple chiral carbons, which further endows rosin with fascinating potential for the construction of chiral nanostructures. Yan et al 24 reported a left-handed helical fiber using a rosin-based amine oxide surfactant (R-6-AO). Zhai et al 26 found a twisted semicircular aggregate using a rosin-derived carboxylate surfactant (C 14 -MPA-Na).…”

Nanometer-Scale Molecular Cluster Surfactants Generate Robust Gel Emulsion Systems for Solid-State Electrolytes

“…9,10 The stabilization of emulsions is critical in gel emulsion preparation for the prevention of droplet coalescence and the achievement of high pack density of emulsions, for example, high internal phase emulsion (HIPE 11 ). Generally, the emulsion droplets can be stabilized by surfactants, amphiphilic polymers, Janus colloidal nanoparticles, or from the trapping effect of percolated low dimensional nanomaterials 12 or fibril assemblies. 13 The colloid stabilizing system claims advantages, for example, low dosages, high robustness, and versatility to different chemical systems 14 over the surfactant systems; however, delicate control of colloids' amphiphilicity or their wetting to both oil and water phases is critical, which requires efforts for surface treatment.…”

“…They inherit promising mechanical properties of gels and hierarchical structural complexity of emulsions and therefore demonstrate broad applications in catalysis, energy storage, food and cosmetic industry, delivery, fluid separation, regenerative medicine, and porous material design. , The stabilization of emulsions is critical in gel emulsion preparation for the prevention of droplet coalescence and the achievement of high pack density of emulsions, for example, high internal phase emulsion (HIPE). Generally, the emulsion droplets can be stabilized by surfactants, amphiphilic polymers, Janus colloidal nanoparticles, or from the trapping effect of percolated low dimensional nanomaterials or fibril assemblies . The colloid stabilizing system claims advantages, for example, low dosages, high robustness, and versatility to different chemical systems over the surfactant systems; however, delicate control of colloids’ amphiphilicity or their wetting to both oil and water phases is critical, which requires efforts for surface treatment. − Meanwhile, the large sizes (hundreds of nanometers to micrometers) of colloidal particles in the biphasic media render them high detachment energy compared to thermal fluctuation energy, leading to jammed and the so-stabilized liquid/liquid interface. − For jammed systems, the mechanical strengths are inversely dependent on the volume of the particle unit, and therefore, pushing down the limit of particle sizes and the feasibility for particle wettability control is urgent for the facile generalization of robust gel emulsions and, more importantly, the spurring of the integration of functional particle systems.…”

Structured Emulgels by Interfacial Assembly of Terpenes and Nanochitin

“…For instance, the presence of charged moieties reduces BE solubilization while increasing intermolecular interactions between electron-deficient groups, such as those featured in the terpene structure combined with acid groups (for instance, in rosin acid, RO). RO brings anionic carboxylic acid groups that engage in electrostatic and dipole–dipole interactions, which have been used to form emulsions or gels. , To reduce their inherent hydrophobicity, a wide variety of amphiphilic molecules based on RO have been synthesized by amination, sulfonation, esterification, or phosphorylation. − However, simple routes that avoid chemical modification are preferred, which is the present case.…”