5 research outputs found
Nanoporous Glass Films on Liquids
Glass-like
thin films are used in many applications as dielectric layers, barrier
coatings, abrasion-resistant films, and/or transparent films. We report
the first direct application of such materials to liquid substrates
using a plasma-deposition process at atmospheric pressure. The study
demonstrates the broader utilization of these materials, for example,
as robust membranes for water harvesting or drug delivery
Large Area Nanostructured Arrays: Optical Properties of Metallic Nanotubes
In
this study, large area metallic nanotube arrays on flexible plastic
substrates are produced by templating the growth of a cosputtered
alloy using anodized aluminum oxide membranes. These nanotube arrays
are prepared over large areas (ca. squared centimeters) by reducing
the residual stress within the thin multilayered structure. The nanotubes
are approximately 20 nm in inner diameter, having walls of <10
nm in thickness, and are arranged in a close packed configuration.
Optically the nanotube arrays exhibit light trapping behavior (not
plasmonic), where the reflectivity is less than 15% across the visible
spectra compared to >40% for a flat sample using the same alloy.
When the nanotubes are exposed to high relative humidity, they spontaneously
fill, with a concomitant change in their visual appearance. The filling
of the nanotubes is confirmed using contact angle measurements, with
the nanotubes displaying a strong hydrophilic character compared to
the weak behavior of the flat sample. The ability to easily fabricate
large area nanotube arrays which display exotic behavior paves the
way for their uptake in real world applications such as sensors and
solar energy devices
Large Area Nanostructured Arrays: Optical Properties of Metallic Nanotubes
In
this study, large area metallic nanotube arrays on flexible plastic
substrates are produced by templating the growth of a cosputtered
alloy using anodized aluminum oxide membranes. These nanotube arrays
are prepared over large areas (ca. squared centimeters) by reducing
the residual stress within the thin multilayered structure. The nanotubes
are approximately 20 nm in inner diameter, having walls of <10
nm in thickness, and are arranged in a close packed configuration.
Optically the nanotube arrays exhibit light trapping behavior (not
plasmonic), where the reflectivity is less than 15% across the visible
spectra compared to >40% for a flat sample using the same alloy.
When the nanotubes are exposed to high relative humidity, they spontaneously
fill, with a concomitant change in their visual appearance. The filling
of the nanotubes is confirmed using contact angle measurements, with
the nanotubes displaying a strong hydrophilic character compared to
the weak behavior of the flat sample. The ability to easily fabricate
large area nanotube arrays which display exotic behavior paves the
way for their uptake in real world applications such as sensors and
solar energy devices
Polymeric Material with Metal-Like Conductivity for Next Generation Organic Electronic Devices
The reduced pressure synthesis of polyÂ(3,4-ethylenedioxythiophene)
(PEDOT) with sheet-like morphology has been achieved with the introduction
of an amphiphilic triblock copolymer into the oxidant thin film. Addition
of the copolymer not only results in an oxidant thin film which remains
liquid-like under reduced pressure but also induces structured growth
during film formation. PEDOT films were polymerized using the vacuum
vapor phase polymerization (VPP) technique, in which we show that
maintaining a liquid-like state for the oxidant is essential. The
resulting conductivity is equivalent to commercially available indium
tin oxide (ITO) with concomitant optical transmission values. PEDOT
films can be produced with a variety of thicknesses across a range
of substrate materials from plastics to metals to ceramics, with sheet
resistances down to 45 Ω/□ (ca. 3400 S·cm<sup>–1</sup>), and transparency in the visible spectrum of >80% at 65 nm thickness.
This compares favorably to ITO and its currently touted replacements
Polymeric Material with Metal-Like Conductivity for Next Generation Organic Electronic Devices
The reduced pressure synthesis of polyÂ(3,4-ethylenedioxythiophene)
(PEDOT) with sheet-like morphology has been achieved with the introduction
of an amphiphilic triblock copolymer into the oxidant thin film. Addition
of the copolymer not only results in an oxidant thin film which remains
liquid-like under reduced pressure but also induces structured growth
during film formation. PEDOT films were polymerized using the vacuum
vapor phase polymerization (VPP) technique, in which we show that
maintaining a liquid-like state for the oxidant is essential. The
resulting conductivity is equivalent to commercially available indium
tin oxide (ITO) with concomitant optical transmission values. PEDOT
films can be produced with a variety of thicknesses across a range
of substrate materials from plastics to metals to ceramics, with sheet
resistances down to 45 Ω/□ (ca. 3400 S·cm<sup>–1</sup>), and transparency in the visible spectrum of >80% at 65 nm thickness.
This compares favorably to ITO and its currently touted replacements