Site-Specific Recognition of Nanophase-Separated Surfaces of Amphiphilic Block Copolymers by Hydrophilic and Hydrophobic Gold Nanoparticles

Reactive block copolymers for patterned surface immobilization with sub-30 nm spacing

Reactive polystyrene-block-polyisoprene copolymers are synthesized by nitroxide-mediated polymerization, self-assemble within ultra-thin films, and exhibit surface reactivity for patterned immobilization.

High-Resolution Metal Nanopatterning by Means of Switchable Block Copolymer Templates

In this review, recent developments in the fabrication of hexagonal and parallel ordered arrays of metallic nanodomains on a substrate are described. We focus on the nanopatterning approach by means of switchable block copolymer thin films. This approach is highly advantageous, because it can lead to extremely regular patterns with metal subunits of only a few nanometers in diameter and center-to-center distances of tens of nanometers. Hence, the resulting 1D or 2D periodic arrays of metal nanodots and nanowires on silicon substrates can be fabricated with extremely high unit densities and on very large areas. The templated deposition of presynthesized metal nanoparticles on functional block copolymers is described in detail. Current challenges are discussed and an outlook for further developments is given.

Linear assembly of a porphyrin–C60 complex confined in vertical nanocylinders of amphiphilic block copolymer films

Linear assemblies of a 1 : 1 porphyrin–fullerene C₆₀ complex were formed in vertical cylindrical polyether nanodomains of amphiphilic block copolymer films.

Liquid-crystalline ordering helps block copolymer self-assembly

Interaction between liquid-crystalline elastic deformation and microphase separation in liquid-crystalline block copolymers enables them to supramolecularly assemble into ordered nanostructures with high regularity. With the help of liquid-crystalline alignment, parallel and perpendicular patterning of nanostructures is fabricated with excellent reproducibility and mass production, which provides nanotemplates and nanofabrication processes for preparing varieties of nanomaterials. Furthermore, nanoscale microphase separation improves the optical performance of block-copolymer fi lms by eliminating the scattering of visible light, leading to advanced applications in optical devices and actuators. Recent progress in liquid-crystalline block copolymers, including their phase diagram, structure-property relationship, nanostructure control and nanotemplate applications, is reviewed.

Photoresponsive block copolymers containing azobenzenes and other chromophores

Photoresponsive block copolymers (PRBCs) containing azobenzenes and other chromophores can be easily prepared by controlled polymerization. Their photoresponsive behaviors are generally based on photoisomerization, photocrosslinking, photoalignment and photoinduced cooperative motions. When the photoactive block forms mesogenic phases upon microphase separation of PRBCs, supramolecular cooperative motion in liquid-crystalline PRBCs enables them to self-organize into hierarchical structures with photoresponsive features. This offers novel opportunities to photocontrol microphase-separated nanostructures of well-defined PRBCs and extends their diverse applications in holograms, nanotemplates, photodeformed devices and microporous films.

Placement control of nanomaterial arrays on the surface-reconstructed block copolymer thin films

We present a control strategy for the facile placement of densely packed nanomaterial arrays (i.e., nanoparticles and nanorods) on surface reconstructed polystyrene-block-poly(methyl methacrylate) thin film patterns. The surface reconstruction of perpendicularly oriented block copolymer thin films, which were produced by a treatment with selective solvent vapors for both blocks, created the topographical nanopatterns with enough height contrast for nanoparticle deposition without the need for additional selective etching of a single block domain. The deposition method of nanomaterials was also optimized, and densely packed one- and two-dimensional nanomaterials arrays in the grooves of the block copolymer film patterns were fabricated efficiently. Then, we demonstrated that height contrast of the surface reconstructed block copolymer films could be reversed by electron beam irradiation resulting in nanomaterial arrays placed at the mesa phase of the nanopatterns. On the basis of this nanomaterial placement control strategy, dual nanomaterial arrays on a single block copolymer pattern were also realized.

Block copolymer nanolithography: translation of molecular level control to nanoscale patterns

The self-asembly of block copolymers is a promising platform for the "bottom-up" fabrication of nanostructured materials and devices. This review covers some of the advances made in this field from the laboratory setting to applications where block copolymers are in use.