Interfacial activity of patchy worm-like micelles

Abstract

The interfacial activity of self-assembled worm-like crystalline-core micelles (wCCMs) with a patchy polystyrene/poly(methyl methacrylate) (PS/PMMA) corona and a semi-crystalline polyethylene (PE) core is studied at the toluene-water interface. Strikingly, the interfacial activity is comparable to that of Janus cylinders with well-separated PS/PMMA hemishells and comparable length. From this finding an adaptation of the corona chains of the patchy wCCMs to the toluene-water interface is proposed. Surface compartmentalization in nanoparticles leads to a variety of unique elds of application, e.g. the self-assembly into hierarchical superstructures or the selective incorporation of multiple nanoparticles or dyes into dened spatial connement. 1,2 Another fascinating attribute of surface-compartmentalized nanostructures is their outstanding surface activity. The combination of the "Pickering effect" 3-5 valid for particles at interfaces with the amphiphilicity of classical surfactants makes them ideal candidates for a new generation of superior surfactants or to produce functional assemblies. 6 Research on surface-compartmentalized nanostructures until now has mainly focused on Janus particles that, named aer the two-faced Roman god Janus, exhibit exactly two opposing hemishells of different chemistry and/or polarity. 7,8 Dense, solid Janus colloids with sizes ranging in the micrometer region and slightly below have been synthesized using various techniques during the last decade, mainly resulting in spherical geometries. 9-12 Stepping down further in size, block terpolymer based spherical, cylindrical, ribbon-like and disc-like Janus micelles with crosslinked cores were prepared via a template-assisted approach. 13-16

Self-assembly concepts for multicompartment nanostructures

“…Terpolymer-based Janus nanoparticles are colloidal amphiphiles and feature two hemispheres differing in chemical and/or physical properties, which is the origin of their extraor-dinary high interfacial activity and their versatile self-assembly behavior in selective solvents. [260][261][262][263][264] Amphiphilic polystyreneblock-polybutadiene-block-poly(methacrylic acid) (SBMAA) Please do not adjust margins Please do not adjust margins Janus nanoparticles self-assemble into spherical clusters of defined number after reducing the solvent quality for the PS hemisphere (e.g. water).…”

Patchy Micelles with a Crystalline Core: Self-Assembly Concepts, Properties, and Applications

“…This originates from the unique interfacial activity of these materials [ 38 ]. Patchy wCCMs were proven to show not only a superior interfacial activity compared to cylindrical micelles with a homogeneous PS corona, but also an identical interfacial activity compared to that of Janus micelles at a water–toluene interface ( Figure 9 a) [ 159 ]. Although Janus particles consist of only two clearly separated compartments (or faces), which facilitates the orientation at interfaces, the unique corona structure of patchy micelles is able to adapt to the requirements of the interface, i.e., the respective insoluble block will collapse and the soluble block will expand.…”

“…patchy CNTs (bottom). ( a ) Reproduced from [ 159 ] with permission of Elsevier and ( b , c ) reproduced from [ 162 ] with permission of ACS.…”

Properties of Styrene–Maleic Anhydride Copolymer Compatibilized Polyamide 66/Poly (Phenylene Ether) Blends: Effect of Maleic Anhydride Concentration and Copolymer Content

“…Phase separation leads to the formation of weak interfaces and cause high stress concentrations locally when under load. In order to control the phase separation, various compatibilization methods are applied, such as the addition of low-molecular-weight organic molecules [10][11][12][13], inorganic nanoparticles [14][15][16][17], Janus-type hybrid materials [18][19][20][21], and copolymers with functional moieties [22][23][24][25][26].…”