Stimuli-responsive surfactants

Abstract

Recent progress in stimuli-responsive surfactants is reviewed, covering control of both interfaces and bulk solution properties. Particular attention is devoted to potential future directions and applications.

Responsive self-assemblies based on fatty acids

“…3 the action of pH, CO 2 and temperature. The modifications occurring at the molecular level under stimuli lead to modifications of the fatty acid self-assembled structures in aqueous solution at the mesoscopic scale.…”

“…Stimuliresponsive surfactants that can change their structure in response to a trigger such as pH, temperature, light or magnetic field have attracted great attention due to their versatile applications in various fields (e.g.pharmaceutical, biomedical, nanotechnology, etc.) [2]. A change in the molecular structure of the surfactant activated by stimuli can affect the selfassembled structure in water and the interfacial activity, which can in turn tune the properties at the macroscopic scale such as viscosity, emulsion and foam stability [2].…”

“…[2]. A change in the molecular structure of the surfactant activated by stimuli can affect the selfassembled structure in water and the interfacial activity, which can in turn tune the properties at the macroscopic scale such as viscosity, emulsion and foam stability [2].…”

Self-Assembly Mechanism of pH-Responsive Glycolipids: Micelles, Fibers, Vesicles, and Bilayers

“…1 Block copolymers and lipids are commonly designed to tune their self-assembly properties in solution as a function of temperature (e.g., use of N-isopropylacrylamide residues), pH (use of amine or carboxylic acid residues), ionic force (use of charged residues), etc. 2 Typical self-assembled structures range, for example, from simple spherical to branched micelles, disks, vesicles, sheets, and fibers, 1,3−5 and the morphological relationship between them is generally considered to rely on the molecular structure, according to the well-known packing parameter relationship. 6 Cone-like molecular morphologies tend to form curved objects, like micelles, while cylinder-shaped molecules rather form bilayers.…”

Magnetic surfactants

“…A more sophisticated approach is to use external stimuli to activate reversible changes in molecular structures with responsive surfactants [5]. This has been achieved through sensitivity towards changes in CO2 levels [6], light [7], enzymes [8] and electrical potential (redox) [9].…”