Tuning the assembly of amphiphilic block copolymers through instabilities of solvent/water interfaces in the presence of aqueous surfactants

Abstract

The influence of the water-soluble surfactant sodium dodecyl sulfate (SDS) on the self-assembly of amphiphilic block copolymers through hydrodynamic instabilities of organic solvent/water interfaces was studied. Micropipette aspiration measurements performed on evaporating chloroform droplets containing polystyrene-b-poly(ethylene oxide) (PS-PEO) revealed that interfacial instabilities were correlated to an approach of the organic/water interfacial tension to zero. The addition of SDS to the aqueous phase lowered the interfacial tension, thereby facilitating the onset of instability at lower concentrations of PS-PEO within the droplets. Further, increased amounts of SDS led to qualitatively different mechanisms of interfacial instability and correspondingly different morphologies of the resulting copolymer/surfactant assemblies. Similar, though less pronounced, effects were obtained using poly(vinyl alcohol) (PVOH) as a water-soluble surfactant, reflecting its more weakly concentration-dependent surface activity. These results enabled a single PS-PEO or polybutadiene-PEO block copolymer of fixed composition to be processed into aggregates that could be easily tuned from multi-vesicular particles to wormlike micelles and to spherical micelles.

Shell phase selection and layer numbers of core–shell structure in monotectic alloys with stable miscibility gap

“…For example, the addition of a water-soluble surfactant sodium dodecyl sulfate (SDS) to the aqueous phase can lower the polystyrene-b-poly(ethyleneoxide) (PS-PEO)/water interfacial tension nearly to zero [24,25]. If such kind of surfactants is used or the material of the container wall is selected, the interfacial energy could be changed.…”

“…The other situation is for the separated phases in the solutions, their interfacial energy can be altered by some surfactants [24,25]. For example, the addition of a water-soluble surfactant sodium dodecyl sulfate (SDS) to the aqueous phase can lower the polystyrene-b-poly(ethyleneoxide) (PS-PEO)/water interfacial tension nearly to zero [24,25].…”

Multicompartment Vesicles Formation by Emulsification‐Induced Assembly of Poly(ethylene oxide)‐block‐poly(ε‐caprolactone) and Their Dual‐Loading Capability

“…In particular, key parameters in determining the degree of interfacial instability affecting the generation of nanoparticles from emulsion droplets have been investigated using coil‐to‐coil block copolymers . First of all, a synergistic adsorption of the surfactant with amphiphilic polymers to the surface of the emulsion droplet resulted in dramatically decreased interfacial tension and generated interfacial instability at the droplet surface.…”

“…First of all, a synergistic adsorption of the surfactant with amphiphilic polymers to the surface of the emulsion droplet resulted in dramatically decreased interfacial tension and generated interfacial instability at the droplet surface. The composition and concentration of both the polymer and the surfactant should be considered to control the resultant particles after evaporation of the organic solvent . In addition, since the droplets are generated at the liquid–liquid interface, the oil phase also should be carefully selected through consideration of the interfacial tension with the water phase .…”

Preparation of non‐spherical particles from amphiphilic block copolymers

“…Many synthetic systems have been developed that take inspiration from natures outstanding self‐assembly abilities, including phospholipids, peptide amphiphiles and more recently amphiphilic and ionic block copolymers (BCPs) . BCPs serve as versatile building blocks to fabricate a range of self‐assembled structures, such as micelles, structured microparticles, nanostructured particles, cross‐linked particles, and multivesicular particles . Furthermore, the last decade has witnessed an emerging interest in developing methods to prepare non‐conventional BCP particles that assemble into complex supramolecular structures…”