Morphology and microphase separation of star copolymers

Abstract

Star copolymers have attracted significant interest due to their different characteristics compared with diblock copolymers, including higher critical micelle concentration, lower viscosity, unique spatial shape, or morphologies. Development of synthetic skills such as anionic polymerization and controlled radical polymerization have made it possible to make diverse architectures of polymers. Depending on the molecular architecture of the copolymer, numerous morphologies are possible, for instance, Archimedean tiling patterns and cylindrical microdomains at symmetric volume fraction for miktoarm star copolymers as well as asymmetric lamellar microdomains for star-shaped copolymers, which have not been reported for linear block copolymers. In this review, we focus on morphologies and microphase separations of miktoarm (A m B n and ABC miktoarm) star copolymers and starshaped [(A-b-B) n ] copolymers with nonlinear architecture.

Star Polymers

“…407 The most commonly studied star polymers for such assembly processes are star copolymers with heteroarms emanating from a central core (i.e., A m B n : miktoarm stars) and stars with homoarm block copolymers emanating from the core (i.e., (A-b-B) n : star block copolymers). The benefit of using miktoarm star polymers for the formation of bulk nanostructured assemblies is the ease with which they form three-dimensional periodic rather than two-dimensional structures.…”

Radiation damage in polymer films from grazing‐incidence X‐ray scattering measurements

“…The first technique is called grazing‐incidence small angle X‐ray scattering (GISAXS) . This measurement records the off‐specular small angle scattering from embedded nanostructures, and is used to study the structure in thin films of block copolymers, polymer blends, and polymer nanopatterns . The second technique is termed grazing‐incidence wide angle X‐ray scattering (GIWAXS) .…”

Directional Self‐Assembly of Fluorinated Star Block Polymer Thin Films Using Mixed Solvent Vapor Annealing

“…As one of the possible architectural designs, star‐shaped (AB) n BPs are particularly promising for the fabrication of reduced‐feature‐size nanostructures . Matsen et al theoretically predicted that star‐shaped BPs would have a reduced ( χN ) c as the number of arms ( n ) is increased, such that lower‐ N arms with a fixed χ‐ value (i.e., same chemical constituents) could be used, while remaining above ( χN ) c .…”