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Abstract: Rod–coil block copolymers are an increasingly important class of molecules for the self-assembly of functional polymer systems, many of which have rodlike chain conformations due to rigid secondary structures, extended π-conjugation, or aromatic groups along the polymer backbone. Examples of these polymers are helical proteins, polyisocyanates, main-chain semiconducting polymers, and aromatic polyesters, polyamides, or polyimines. Many hindered or liquid crystalline systems self-assembled from block copolymers, including dendronized polymers and mesogen-jacketed liquid crystalline polymers, also form rod–coil block copolymers. In these cases, steric crowding of the bulky or mesogenic side chains causes the polymer backbone to become quasi-linear. The incorporation of rigid rod polymers into the block copolymers results in extremely rich self-assembly behavior that differs markedly from that of traditional block copolymers due to the interplay between microphase separation of the rod and coil components and liquid crystalline alignment. The combination of these effects results in novel structures both in solution and melts. This review discusses in detail the self-assembly and thermodynamics of rod–coil diblock and triblock copolymers. After summarizing the applications of these materials, their aggregation and gelation in solution is discussed. Our knowledge of their bulk phase behavior is thoroughly reviewed both from the experimental and theoretical perspectives, and the self-assembly of these materials in thin film geometries that are critical to many applications in organic electronics and functional surface patterning is treated. Finally, the outlook for the future of these systems is summarized along with current knowledge gaps and exciting areas for the advancement of the field. [Copyright &y& Elsevier]

Abstract: The nanometer-scale architectures in thin films of self-assembling block copolymers have inspired a variety of new applications. For example, the uniformly sized and shaped nanodomains formed in the films have been used for nanolithography, nanoparticle synthesis, and high-density information storage media. Imperative to all of these applications, however, is a high degree of control over orientation of the nanodomains relative to the surface of the film as well as control over order in the plane of the film. Induced fields including electric, shear, and surface fields have been demonstrated to influence orientation. Both heteroepitaxy and graphoepitaxy can induce positional order on the nanodomains in the plane of the film. This article will briefly review a variety of mechanisms for gaining control over block copolymer order as well as many of the applications of these materials. Particular attention is paid to the potential of perfecting long-range two-dimensional order over a broader range of length scales and the extension of these concepts to functional materials and more complex architectures. [Copyright &y& Elsevier]

Abstract: Block copolymer thin films with distinct morphologies are prepared by spin casting a nominally lamellar assay of poly(styrene-block-ethylene oxide) from a variety of solvents with and without salt doping. The 3-D morphologies of free-standing thin-film regions, which are obtained by casting directly onto holey substrates, are investigated in detail using various energy-filtering transmission electron microscopy techniques and by electron tomography. Surface characterization is achieved by atomic force microscopy. Our results demonstrate that in order to fully characterize the unique 3-D morphologies of the block copolymer thin films, a multi-method approach is required. When casting from a binary solvent, an unexpected layered honeycomb-type morphology is revealed, which likely results from an expansion of the poly(ethylene oxide) phase. A dramatic effect of selective cation coordination on the morphology of the as-cast block copolymer films is also directly observed. [Copyright &y& Elsevier]

Abstract: Hybrid devices built from organic and inorganic moieties are being actively researched as replacements for inorganic electronics, thermoelectrics, and photovoltaics. However, energy transport and conversion, at the organic–inorganic interface is not well understood. One approach to study this interface is to look at the smallest hybrid building block – the heterojunction of a single organic molecule with inorganic contacts. We present a review of this work, focused on fundamental transport properties of metal–molecule–metal junctions that are related to thermoelectric energy conversion, i.e., electronic conductance, thermopower, and thermal conductance. We describe the motives, strategies, and future directions for considering heterojunctions as building blocks for thermoelectric materials. [Copyright &y& Elsevier]