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Nanostructured Films (nanostructured + film)

Distribution by Scientific Domains
Polymers and Materials Science83%

Selected Abstracts

Energy-Modulated Heterostructures Made with Conjugated Polymers for Directional Energy Transfer and Carrier Confinement,

ADVANCED FUNCTIONAL MATERIALS, Issue 15 2007
R. Favarim
Abstract In this paper we demonstrate that multilayer structures with modulated bandgaps can be used for efficient energy transfer and carrier confinement inside a nanostructured film of a light-emitting polymer. The films were produced with the layer-by-layer technique (LbL) with a poly(p -phenylene vinylene) (PPV) precursor and a long chain dodecylbenzenesulfonate ion (DBS). DBS is incorporated selectively into the precursor chain, and with a rapid, low temperature conversion process (100,°C) superstructures with variable HOMO,LUMO gap could be formed along the deposition direction by changing the DBS concentration. Structures with different stair-type energy modulations were produced, which are thermally stable and reproducible, as demonstrated by UV-VIS. absorption measurements. Energy differences of up to 0.5,eV between the lowest and highest conjugated layers inside the stair structure could be achieved, which was sufficient to guide the excitation over long distances to the lower bandgap layer. [source]

Highly Porous Nano- and Microstructured Films Loaded with Bioactive Agents for Biomedical Applications: Structure,Release Profile Effects

ADVANCED ENGINEERING MATERIALS, Issue 8 2009
Adi Rachelson
The current study focuses on the nanostructuring of our new drug-eluting porous films and its effect on the drug release profile of both hydrophilic and hydrophobic drugs. Nanostructuring was obtained using both the dispersion and the condensation methods of emulsion processing. These new highly porous nanostructured films can be used as basic elements of various drug-eluting medical devices. [source]

Surface-Grafted Gel-Brush/Metal Nanoparticle Hybrids

ADVANCED FUNCTIONAL MATERIALS, Issue 6 2010
Edmondo M. Benetti
Abstract Polymer brushes are classically defined and are to date employed as assemblies of macromolecules tethered at one end to a surface. The concept of preparing surface-grafted gels by crosslinking such brushes is attractive since it gives rise to new opportunities related to the constraints present in this type of structure. Aiming at the development of nanostructured films possessing precisely adjustable chemical, mechanical, and optical properties, the present article describes the preparation of novel grafted layers based on gel-brush/metal nanoparticle hybrids. These films were synthesized by surface-initiated atom transfer radical polymerization of hydroxyethyl methacrylate with a small percentage of a crosslinker. The swelling, morphological, and mechanical properties of the gel-brushes are shown to be highly dependent on the relative amount of crosslinker used. The gel-brushes are subsequently used as matrixes for the controlled synthesis of silver nanoparticles with overall characteristics that are specifically tunable as a function of the macromolecular structure of the brush template. [source]

Long-Range-Ordered, Molecular-Induced Nanofaceting,

ADVANCED MATERIALS, Issue 21 2006
M. Fanetti
Ordered molecular nanostructured films (see figure) are obtained by exploiting the molecular-induced substrate faceting transition, following a very simple protocol. The obtained nanostructures show univocal alignment and quite good homogeneity, and the pattern periodicity can be controlled in the process. The stepped structure of the vicinal metallic substrate has a key role in the film production mechanism. [source]

Morphology in-Design Deposition of HfO2 Thin Films

JOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 10 2008
Ni Jie
We investigated factors influencing the growth morphology of hafnium dioxide (HfO2) thin films by glancing angle deposition, and found that a shape factor defined as the ratio of the deposition rate over the substrate rotation speed played a key role in determining the morphology of the films. By adjusting this factor, we fabricated successfully films of aligned HfO2 nanorods, nanosprings, and nanohelix. Comparing with the flat films, these nanostructured films exhibited enhanced light transmittance and photocatalytic activity in hydrogen production from water splitting under ultraviolet radiation. [source]

Controlled Hydrothermal Synthesis and Growth Mechanism of Various Nanostructured Films of Copper and Silver Tellurides

CHEMISTRY - A EUROPEAN JOURNAL, Issue 15 2006
Lizhi Zhang Prof.
Abstract Various nanostructured films of copper and silver tellurides were hydrothermally grown on the corresponding metal substrates through reactions between metal foils and tellurium powder in different media. Interesting morphologies including nanowires, nanorods, nanobelts, nanosheets, and hierarchical dendrites were obtained. The nanostructured films were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution TEM (HRTEM). A growth mechanism was proposed based on the characterization results. This study provides a low-temperature, solution-phase approach to grow low-dimensional, nanostructured metal tellurides with controllable morphologies. [source]