Abstract: Owing to the increasing interest in self-assembled structures from block copolymer materials, we present here a review of recent literature concerning amphiphilic block copolymer vesicles. A vesicular morphology is applicable not only in such fields like delivery–release and biomineralization, but also has been utilized for preparation of nanoreactors and incorporation of biological macromolecules. The organization of this paper is the following: we first provide the readers with the overview of the current literature concerning the vesicle preparation and most commonly used experimental methods applied for vesicle investigations. Next, we consider the vesicle formation in more detail and present the morphologies resulting from the interplay of factors influencing vesicular structures in solution. Further, membrane properties will be reviewed, and finally, we wish to focus on our group's achievements in studying nanocontainers from both ABA and ABC amphiphilic block copolymers.
TL;DR: The methods considered are colloidosome formation, polymer precipitation by phase separation, polycondensation interfacial polymerisation, layer-by-layer polyelectrolyte deposition, polymer growth by surface polymerisation and copolymer vesicle formation.
Abstract: Polymer shell microcapsules with liquid cores are used in a wide variety of industries, from food and flavour protection to inkless paper. There is a number of production methods, each with different characteristics and this article reviews a number of them. The methods considered are colloidosome formation, polymer precipitation by phase separation, polycondensation interfacial polymerisation, layer-by-layer polyelectrolyte deposition, polymer growth by surface polymerisation and copolymer vesicle formation. Each production method is described and the relative strength of each is outlined.
TL;DR: A needle-like solid is obtained on drying of aqueous solutions of the spherical micelles of the highly asymmetric polystyrene-poly-(acrylic acid) block copolymers prepared in a low molecular weight solvent system.
Abstract: The observation by transmission electron microscopy of six different stable aggregate morphologies is reported for the same family of highly asymmetric polystyrene-poly-(acrylic acid) block copolymers prepared in a low molecular weight solvent system. Four of the morphologies consist of spheres, rods, lamellae, and vesicles in aqueous solution, whereas the fifth consists of simple reverse micelle-like aggregates. The sixth consists of up to micrometer-size spheres in aqueous solution that have hydrophilic surfaces and are filled with the reverse micelle-like aggregates. In addition, a needle-like solid, which is highly birefringent, is obtained on drying of aqueous solutions of the spherical micelles. This range of morphologies is believed to be unprecedented for a block copolymer system.
Abstract: Crew-cut micelle-like aggregates of various morphologies prepared from polystyrene-b-poly(acrylic acid), PS-b-PAA, diblock copolymers under near-equilibrium conditions, were studied by transmission electron microscopy (TEM). The insoluble block (PS) contents in the copolymers ranged from 80 to 98 wt %. In spherical micelles, the micelle cores, formed by aggregation of the PS blocks, were generally monodisperse. A comparison between star and crew-cut micelles showed that the latter are distinguished by a low density of corona chains on the core surface and a low degree of stretching of the PS blocks in the cores. As the PAA content in block copolymer decreased, the morphology of the aggregates changed progressively from spheres to cylinders, to bilayers (both vesicles and lamellae), and eventually to compound micelles consisting of an assembly of inverted micelles surrounded by a hydrophilic surface. The compound micelles are believed to be a new morphology for block copolymers. The addition of homopolysty...
Abstract: Polysilylenes, the linear silicon-silicon bonded polymers, have several interesting properties and are a subject of current intense investigations. Polysilylenes are prepared mostly by the Wurtz-type coupling reactions of dichlorodialkylsilanes which, however, have several difficulties such as the poor control of structure, molecular weight, and polydispersity. The yields of polymers are also usually low. In this paper, we will describe an entirely novel method of preparing polysilylenes based on anionic polymerization of masked disilenes.