Polymers with the same chemical composition can provide different properties by reducing the dimension or simply by altering their nanostructure. The recent literature reports hundreds of examples of advanced methods in the fabrication of polymer nanostructures accomplished following a variety of approaches, such as soft lithography, self-assembly routes, template assisted methods, etc. Polymer nanostructures with modulated morphologies and properties can be easily achieved from anodized aluminum oxide (AAO) template assisted methods. In the last decade, fabrication of polymer nanostructures in the nanocavities of AAOs has increased in interest since it allows the control and tailoring of the dimensions of a huge number of polymer and polymer-based composites materials. The fact that polymer dimensions may be adjusted allows the study of size-dependent properties. Moreover, using AAO template methods, modulated polymer nanostructures may be designed for specific applications. This review presents recent new insights in the fabrication methods of polymer nanostructures from hard porous AAO templates, with emphasis on the study of polymer structure/property relationships on the nanometric length scale, stressing potential interests in relevant applications. The discussion includes (i) a description of the anodizing methods and strategies to obtain AAO templates with adjusted dimensions; (ii) a summary of different infiltration methods, starting with the infiltration of a polymeric fluid (melt or solution) into the nanocavities of the AAO template, to conform a great number of the polymer nanostructures with different morphologies, the approach to obtain directly polymer nanostructures by in-situ polymerization of a monomer within AAO nanocavities and the effect of confinement in the AAO nanoreactor on the polymerization kinetics; (iii) an overview of the effects of confinement on structural aspects, dynamical processes and the mechanical, thermal and rheological properties of the polymer; (iv) examples of polymer nanostructures as precursors in bio-, adhesion, optical and electrical related applications; and finally (v) a summary of conclusions and suggested challenges.Acknowledgments Authors are gratefully acknowledged to the Ministerio de Economía y Competitividad for their financial support (MAT2011-24797 and MAT2014-53437). Rebeca Hernández thanks MEC for a Ramon y Cajal contract. Jaime Martína cknowledges support from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 654682Peer Reviewe

We present neutron spin echo experiments that address the much debated topic of dynamic phenomena in polymer melts that are induced by interacting with a confining surface. We find an anchored surface layer that internally is highly mobile and not glassy as heavily promoted in the literature. The polymer dynamics in confinement is, rather, determined by two phases, one fully equal to the bulk polymer and another that is partly anchored at the surface. By strong topological interaction, this phase confines further chains with no direct contact to the surface. These form the often invoked interphase, where the full chain relaxation is impeded through the interaction with the anchored chains.

Polymer nanotechnology allows manipulating materials microstructure, morphology and compositional variation on the nanometer scale. Thus, it is able to provide materials for many cutting edge applications, from photonics to medical devices to sensors. This article summarizes recent work on template-based fabrication and on the basic properties of one-dimensional polymeric nanostructures and their inherent advantages over their conventional counterparts. The chemistry and physics relevant for the design of these nanostructured materials are discussed and recent advances emphasized. In particular, highlighting the effects of nanoconfinement on material behavior and putting somewhat greater emphasis on molecular motions. Some examples of one-dimensional-based polymeric nanostructures with promising applications for example in the field of tissue engineering are also presented as well as some aspects concerning recyclability of the used templates

We review previous works on polymer confined crystallization employing strategies that allow confinement to go from the micron to the nanometer scale: droplets, blends, block copolymers and infiltration into alumina nanopores. We also present novel results, reporting homogeneous nucleation and first order crystallization kinetics, for the first time, in a homopolymer and a diblock copolymer infiltrated within alumina nanopores. Confinement can produce fractionated crystallization or exclusive crystallization at much higher supercoolings as compared to bulk polymers, as the degree of confinement increases. For highly confined heterogeneity free micro or nano-domains, the overall crystallization kinetics is dominated by nucleation and therefore becomes first order. The nucleation mechanism changes from heterogeneous nucleation for the bulk polymer to surface or homogeneous nucleation for ensembles of confined and isolated heterogeneity free micro or nanodomains. Surface nucleation is more commonly found than homogenous nucleation, although this fact is not frequently recognized in the literature.Peer Reviewe

Biological materials achieve directional reinforcement with oriented assemblies of anisotropic building blocks. One such example is the nanocomposite structure of keratinized epithelium on the toe pad of tree frogs, in which hexagonal arrays of (soft) epithelial cells are crossed by densely packed and oriented (hard) keratin nanofibrils. Here, a method is established to fabricate arrays of tree-frog-inspired composite micropatterns composed of polydimethylsiloxane (PDMS) micropillars embedded with polystyrene (PS) nanopillars. Adhesive and frictional studies of these synthetic materials reveal a benefit of the hierarchical and anisotropic design for both adhesion and friction, in particular, at high matrix–fiber interfacial strengths. The presence of PS nanopillars alters the stress distribution at the contact interface of micropillars and therefore enhances the adhesion and friction of the composite micropattern. The results suggest a design principle for bioinspired structural adhesives, especially for wet environments.