Nanoparticles sized tens of nm with not only a highly complex but also a highly regular nanostructure, although ubiquitous in nature, are very difficult to prepare artificially. Herein, we report efficient solution‐based preparation of narrow‐disperse ABC three‐segment hierarchical nanoparticles (HNPs) with a size of tens of nm through a three‐level hierarchical self‐assembly of A‐b‐B‐b‐C triblock copolymers in solution. An ABC HNP is composed of three nanoparticles, A, B, and C that are linearly connected; in the ABC HNP, the B nanoparticle is sandwiched between the A and C nanoparticles. The method for the preparation is highly efficient, because all of the A‐b‐B‐b‐C chains in the solution are converted into the ABC HNPs. Furthermore, the ABC HNPs self‐assembled into Θ‐shaped HNPs tens nm in size. Both the ABC and Θ‐shaped HNPs, are highly complex but highly regular, and are novel HNPs, and they should be very promising for addressing various theoretical and practical problems. 相似文献
Polymer nanocomposite films with unusual and anisotropic optical properties were obtained by the controlled in-situ generation of noble metal nanoparticles (NPs). Poly(vinyl alcohol) (PVA) and poly(ethylene-co-vinylalcohol) (EVAl) nanocomposites containing gold and silver NPs were efficiently produced by a photo-reduction or thermal process both operating directly in the solid state and resulted efficiently stabilized by the presence of polymer hydroxyl groups, which prevent particles agglomeration. Uniaxial drawing of the NPs/polymer composites promoted anisotropic packing of the embedded particles along the stretching direction of the film, resulting in a shift of the surface plasmon resonance well above 40 nm and thus producing a well-defined polarization-dependent colour change. Such nanostructured materials when are obtained in the form of thin films can be applied to several fields, from sensor to photonics (i.e., macromolecular strain sensor, linear absorbing polarizer). 相似文献
The unique optical and electronic properties of living systems are impressive. Peptide-based supramolecular self-assembly systems attempt to mimic these properties by preparation optical/electronic function materials with specific structure through simple building blocks, rational molecular design, and specific kinetic stimulation. From the perspective of building blocks and assembly strategies, the unique optical and electronic properties of peptide-based nanostructures, including peptides self-assembly and peptides regulate the assembly of external function subunits, are systematically reviewed. Additionally, their applications in biomedicine, sensing, and energy storage are also highlighted. This bioinspired peptide-based function material is one of the hot candidates for the new generation of green intellect materials, with many advantages such as biocompatibility, environmental friendliness, and adjustable morphology. 相似文献
The creation of hierarchical nanostructures in polymeric materials has been intensively studied due to the great potential to tailor their physicochemical properties. Although much success has been achieved over the past decades in block copolymers, hierarchical structure engineering in polymer blends remains a great challenge. Here, the formation of hierarchical lamellae‐in‐lamella nanostructures from polymer blends via controlled nonequilibrium freezing is reported. Polymer blends are first dissolved in molten hexamethylbenzene (HMB) to form a homogeneous melt. When cooled to below its melting temperature, the HMB is crystallized and depleted, and the polymers are directionally solidified. This process is rapid enough that phase separation of the polymer blends is kinetically trapped at the nanoscale level. Then, the polymer blend epitaxially crystallizes onto the HMB inside the nanophase, resulting in the hierarchical lamellae‐in‐lamella structure. This structure is stable under ambient conditions and tunable depending on the annealing temperature and blending ratio.
In this work the primary mechanical property profiles of a specific class of nano‐structured polymer/inorganic hybrid materials are characterized. By utilizing sol‐gel aluminosilicate synthesis with amphiphilic polyisoprene‐block‐poly(ethylene oxide) block copolymers as structure‐directing agents, block copolymer/aluminosilicate hybrid materials are prepared with nanometer scale hexagonally packed cylinders and lamellae of the inorganic hybrid components, as evidenced by small‐angle X‐ray scattering. Systematic thermal and dynamic mechanical analyses are performed on these hybrids as well as on the constituting components. Results reveal two transitions from the low temperature, glassy state of the hybrids into high temperature elastic plateau regions, with moduli that vary over orders of magnitude as a function of composition and morphology. The first transition can be assigned to the glass transition of the PI domains while the second is ascribed to a temperature induced softening of the organic components within the PEO/hybrid domains. The results suggest that in the present nanostructured block copolymer/aluminosilicate hybrid materials composition and morphology provide a powerful tool to tailor mechanical property profiles.
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