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© 2018 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim Optical metamaterials offer the tantalizing possibility of creating extraordinary optical properties through the careful design and arrangement of subwavelength structural units. Gyroid-structured optical metamaterials possess a chiral, cubic, and triply periodic bulk morphology that exhibits a redshifted effective plasma frequency. They also exhibit a strong linear dichroism, the origin of which is not yet understood. Here, the interaction of light with gold gyroid optical metamaterials is studied and a strong correlation between the surface morphology and its linear dichroism is found. The termination of the gyroid surface breaks the cubic symmetry of the bulk lattice and gives rise to the observed wavelength- and polarization-dependent reflection. The results show that light couples into both localized and propagating plasmon modes associated with anisotropic surface protrusions and the gaps between such protrusions. The localized surface modes give rise to the anisotropic optical response, creating the linear dichroism. Simulated reflection spectra are highly sensitive to minute details of these surface terminations, down to the nanometer level, and can be understood with analogy to the optical properties of a 2D anisotropic metasurface atop a 3D isotropic metamaterial. This pronounced sensitivity to the subwavelength surface morphology has significant consequences for both the design and application of optical metamaterials.

High-aspect-ratio sub-15-nm silicon trenches are fabricated directly from plasma etching of a block copolymer mask. A novel method that combines a block copolymer reconstruction process and reactive ion etching is used to make the polymer mask. Silicon trenches are characterized by various methods and used as a master for subsequent imprinting of different materials. Silicon nanoholes are generated from a block copolymer with cylindrical microdomains oriented normal to the surface.

Self-assembling block copolymer films provide access to a variety of different nanostructured patterns in one, two, and three dimensions. However, in the absence of any templating, these nanostructures suffer from defects, often limiting utility. Directed block copolymer self-assembly uses patterned substrates that effectively suppress defect formation and allow the creation of desired patterns. The two main directed self-assembly techniques, chemoepitaxy and graphoepitaxy, employ chemically and topographically patterned substrates, respectively, to direct the block copolymer assembly in thin films. Their successful application in generating defect-free patterns in films of block copolymers exhibiting particular morphologies is summarized in this concept article. The possible role of directed self-assembly in extending nanostructured patterning from two to three dimensions is also discussed.

We report on the formation of polymer nanofibers and nanotubes by melt infiltration of block copolymers (BCPs) containing poly (norbornene) blocks bearing polar and non-polar moieties synthesized via ring opening metathesis polymerization (ROMP) into Al 2 O 3 porous templates. The effect of pore size of the Al 2 O 3 template and polymer chain length on the formed structure i.e. fibers or hallow tubes is investigated. SEM analysis revealed that a smaller pore size (∼ 1 80 nm) of the Al 2 O 3 template with a BCP of lower molecular weight ( 25 kg/mol) furnishing hollow tubes.

The properties of supramolecular polymers in the solid state are strongly dependent on the binding strength of the supramolecular motifs used; however, It has been previously shown that the nanostructure of supramolecular polymers plays an equally important role. Supramolecular polymers are commonly synthesized via end-group functionalization of low-glass transition telechelics with supramolecular units. In these systems, the binding motifs segregate from the soft telechelic backbone and form a hydrogen bonded crystalline hard phase that provides physical cross-links. To date, the reported synthetic approaches do not permit the introduction of a wide variety of supramolecular units with low synthetic effort, which would facilitate studying the structure-property relationships. The use of the Passerini and Ugi multicomponent reactions to synthesize various poly(ethylene-co-butylene) telechelics with diverse amide end-groups is reported. The thermal properties of the supramolecular polymers obtained through their solid-state assembly are investigated and their nanophase- segregation is studied, which is dictated by the end-group volume fraction and the amide–amide hydrogen bonding.

In this work, the influence of carbon nanotubes (CNTs) on the self-assembly of nanocomposite materials made of cylinder-forming polystyrene-block-poly(ethylene- butylene)-block-polystyrene (SEBS) is studied. CNTs are modified with polystyrene (PS) brushes by surface-initiated atom transfer radical polymerization to facilitate both their dispersion and the orientation of neighboring PS domains of the block copolymer (BCP) along modified CNT-PS. Dynamic rheology is utilized to probe the viscoelastic and thermal response of the nanoscopic structure of BCP nanocomposites. The results indicate that nonmodified CNTs increase the BCP microphase separation temperature because of BCP segmental confinement in the existing 3D network formed between CNTs, while the opposite holds for the samples filled with modified CNT-PS. This is explained by severely retarded segmental motion of the matrix chains due to their preferential interactions with the PS chains of the CNT-PS. Moreover, transient viscoelastic analysis reveals that modified CNT-PS have a more pronounced effect on flow-induced BCP structural orientation with much lower structural recovery rate. It is demonstrated that dynamic-mechanical thermal analysis can provide valuable insights in understanding the role of CNT incorporation on the microstructure of BCP nanocomposite samples. Accordingly, the presence of CNT has a significant promoting effect on microstructural development, comparable to that of annealing.