Guided hierarchical co-assembly of soft patchy nanoparticles.

Different polymers can be used in combination to produce coexisting nanoparticles of different symmetry and tailored to co-assemble into well-ordered binary and ternary hierarchical structures. There is considerable practical interest in developing the tools to fabricate multicomponent artificial systems that mimic the hierarchical ordering seen in the natural world — complex biomaterials can be assembled from the simple but precisely defined molecular building blocks. Andre Groschel and colleagues have developed a bottom-up approach that's a step in that direction. Previously they designed simple linear polymers that self-assemble in solution to produce monodisperse nanoparticles with well…

Self-assembly concepts for multicompartment nanostructures.

Compartmentalization is ubiquitous to many biological and artificial systems, be it for the separate storage of incompatible matter or to isolate transport processes. Advancements in the synthesis of sequential block copolymers offer a variety of tools to replicate natural design principles with tailor-made soft matter for the precise spatial separation of functionalities on multiple length scales. Here, we review recent trends in the self-assembly of amphiphilic block copolymers to multicompartment nanostructures (MCNs) under (semi-)dilute conditions, with special emphasis on ABC triblock terpolymers. The intrinsic immiscibility of connected blocks induces short-range repulsion into discre…

Janus Nanostructures from ABC/B Triblock Terpolymer Blends

Lamella-forming ABC triblock terpolymers are convenient building blocks for the synthesis of soft Janus nanoparticles (JNPs) by crosslinking the B domain that is &ldquo

Rational design of ABC triblock terpolymer solution nanostructures with controlled patch morphology

Block copolymers self-assemble into a variety of nanostructures that are relevant for science and technology. While the assembly of diblock copolymers is largely understood, predicting the solution assembly of triblock terpolymers remains challenging due to complex interplay of block/block and block/solvent interactions. Here we provide guidelines for the self-assembly of linear ABC triblock terpolymers into a large variety of multicompartment nanostructures with C corona and A/B cores. The ratio of block lengths NC/NA thereby controls micelle geometry to spheres, cylinders, bilayer sheets and vesicles. The insoluble blocks then microphase separate to core A and surface patch B, where NB co…

Self-Assembly of block copolymers into internally ordered microparticles

Abstract Block copolymer (BCP) self-assembly is one of the most versatile concepts for the bottom-up design of functional nanostructures in materials science, nanomedicine and nanotechnology. While BCPs have been extensively studied regarding their microphase separation in bulk and the self-assembly in solution, only recently BCPs were investigated for their ability to form internally ordered microparticles. In this review, we discuss two emerging concepts: (i) the microphase separation of BCPs in the spherical confinement of evaporating emulsion droplets and (ii) the self-assembly of highly asymmetric BCPs under concentrated conditions. While the first concept yields solid and compact mult…

Janus Micelles as effective supracolloidal dispersants for carbon nanotubes

Hidden Structural Features of Multicompartment Micelles Revealed by Cryogenic Transmission Electron Tomography

The demand for ever more complex nanostructures in materials and soft matter nanoscience also requires sophisticated characterization tools for reliable visualization and interpretation of internal morphological features. Here, we address both aspects and present synthetic concepts for the compartmentalization of nanoparticle peripheries as well as their in situ tomographic characterization. We first form negatively charged spherical multicompartment micelles from ampholytic triblock terpolymers in aqueous media, followed by interpolyelectrolyte complex (IPEC) formation of the anionic corona with bis-hydrophilic cationic/neutral diblock copolymers. At a 1:1 stoichiometric ratio of anionic a…

Kinetics of Anionic Living Copolymerization of Isoprene and Styrene Using in Situ NIR Spectroscopy: Temperature Effects on Monomer Sequence and Morphology

The living anionic copolymerization of isoprene (I) and styrene (S) can afford a variety of different polymer microstructures that strongly depend on experimental parameters such as solvent, counte...

Bulk morphologies of polystyrene-block-polybutadiene-block-poly(tert-butyl methacrylate) triblock terpolymers

Abstract The self-assembly of block copolymers in the bulk phase enables the formation of complex nanostructures with sub 100 nm periodicities and long-range order, both relevant for nanotechnology applications. Here, we map the bulk phase behavior of polystyrene-block-polybutadiene-block-poly(tert-butyl methacrylate) (SBT) triblock terpolymers on a series of narrowly distributed polymers with widely different block volume fractions, ϕS, ϕB and ϕT. In dependence of ϕ, we find the lamella–lamella, core-shell cylinder, cylinder-in-lamella and core-shell gyroid morphology, but also a rarely observed cylinder-in-lamella phase. The bulk morphologies are thoroughly characterized by transmission e…

Supramolecular Modification of ABC Triblock Terpolymers in Confinement Assembly

The self-assembly of AB diblock copolymers in three-dimensional (3D) soft confinement of nanoemulsions has recently become an attractive bottom up route to prepare colloids with controlled inner morphologies. In that regard, ABC triblock terpolymers show a more complex morphological behavior and could thus give access to extensive libraries of multicompartment microparticles. However, knowledge about their self-assembly in confinement is very limited thus far. Here, we investigated the confinement assembly of polystyrene-block-poly(4-vinylpyridine)-block-poly(tert-butyl methacrylate) (PS-b-P4VP-b-PT or SVT) triblock terpolymers in nanoemulsion droplets. Depending on the block weight fractio…

Controlling Janus Nanodisc Topology through ABC Triblock Terpolymer/Homopolymer Blending in 3D Confinement

Janus particles have drawn considerable interest as colloidal surfactants, microswimmers, and building blocks for colloidal lattices. So far, research primarily focused on spherical Janus particles for which a number of fabrication methods are well established. Janus particles with geometric anisotropy offer shape-dependent properties in addition to surface anisotropy, but their synthesis is more challenging. Here, we report a variety of polymeric Janus nanoparticles synthesized from ABC triblock terpolymer microphases in microemulsion droplets. Evaporation-induced assembly of the ABC triblock terpolymers led to prolate microparticles with A/C lamellae stacked along the particle’s major axi…

Janus-Micellen als effektive suprakolloidale Dispersionsmittel für Kohlenstoff-Nanoröhren

Controlling Multicompartment Morphologies Using Solvent Conditions and Chemical Modification

The solution self-assembly of amphiphilic diblock copolymers into spheres, cylinders, and vesicles (polymersomes) has been intensely studied over the past two decades, and their morphological behavior is well understood. Linear ABC triblock terpolymers with two insoluble blocks A/B, on the other hand, display a richer and more complex morphological spectrum that has been recently explored by synthetic block length variations. Here, we describe facile postpolymerization routes to tailor ABC triblock terpolymer solution morphologies by altering block solubility (solvent mixtures), blending with homopolymers, and block-selective chemical reactions. The feasibility of these processes is demonst…

The Impact of Janus Nanoparticles on the Compatibilization of Immiscible Polymer Blends under Technologically Relevant Conditions

Several hundred grams of Janus nanoparticles (d ≈ 40 nm) were synthesized from triblock terpolymers as compatibilizers for blending of technologically relevant polymers, PPE and SAN, on industry-scale extruders. The Janus nanoparticles (JPs) demonstrate superior compatibilization capabilities compared to the corresponding triblock terpolymer, attributed to the combined intrinsic properties, amphiphilicity and the Pickering effect. Straightforward mixing and extrusion protocols yield multiscale blend morphologies with "raspberry-like" structures of JPs-covered PPE phases in a SAN matrix. The JPs densely pack at the blend interface providing the necessary steric repulsion to suppress droplet …