23 research outputs found
Single-crystal silver nanowires: Preparation and Surface-enhanced Raman Scattering (SERS) property
Ordered Ag nanowire arrays with high aspect ratio and high density
self-supporting Ag nanowire patterns were successfully prepared using
potentiostatic electrodeposition within the confined nanochannels of a
commercial porous anodic aluminium oxide (AAO) template. X-ray diffraction and
selected area electron diffraction analysis show that the as-synthesized
samples have preferred (220) orientation. Transmission electron microscopy and
scanning electron microscopy investigation reveal that large-area and ordered
Ag nanowire arrays with smooth surface and uniform diameter were synthesized.
Surface-enhanced Raman Scattering (SERS) spectra show that the Ag nanowire
arrays as substrates have high SERS activity.Comment: 5 pages, 4 figure
Fabrication of hydrophobic inorganic coatings on natural lotus leaves for nanoimprint stamps
Hydrophobic inorganic films were obtained by direct deposition of copper or
silicon onto natural lotus leaves by ion beam sputtering deposition technique.
Scanning electron microscopy observations showed a lotus-leaf-like surface
structure of the deposited inorganic films. Hydrophobic nature of the inorganic
films on lotus leaves had been improved compared to the inorganic films
deposited on flat silicon substrates. Water contact angles measured on the
lotus-leaf-like copper and silicon films were 136.3 \pm 8{\deg} and 117.8 \pm
4.4{\deg}, respectively. The hydrophobic lotus-leaf-like inorganic films had
been repeated used as nanoimprint stamps. Negative structures of
lotus-leaf-like inorganic films were obtained on the polystyrene resist layers.Comment: 14 pages, 6 figure
Structural properties and Raman spectroscopy of lipid Langmuir monolayers at the air-water interface
Spectra of octadecylamine (ODA) Langmuir monolayers and egg
phosphatidylcholine (PC)/ODA-mixed monolayers at the air-water interface have
been acquired. The organization of the monolayers has been characterized by
surface pressure-area isotherms. Application of polarized optical microscopy
provides further insight in the domain structures and interactions of the film
components. Surface-enhanced Raman scattering (SERS) data indicate that
enhancement in Raman spectra can be obtained by strong interaction between
headgroups of the surfactants and silver particles in subphase. By mixing ODA
with phospholipid molecules and spreading the mixture at the air-water
interface, we acquired vibrational information of phospholipid molecules with
surfactant-aided SERS effect.Comment: 8 pages, 9 figure
Fabrication of surface-patterned ZnO thin films using sol-gel methods and nanoimprint lithography
Surface-patterned ZnO thin films were fabricated by direct imprinting on ZnO
sol and subsequent annealing process. The polymer-based ZnO sols were deposited
on various substrates for the nanoimprint lithography and converted to
surface-patterned ZnO gel films during the thermal curing nanoimprint process.
Finally, crystalline ZnO films were obtained by subsequent annealing of the
patterned ZnO gel films. The optical characterization indicates that the
surface patterning of ZnO thin films can lead to an enhanced transmittance.
Large-scale ZnO thin films with different patterns can be fabricated by various
easy-made ordered templates using this combination of sol-gel and nanoimprint
lithography techniques.Comment: 17 pages, 5 figures; Published in Journal of Sol-Gel Science and
Technology, 201
Preparation of Highly Crystalline TiO2 Nanostructures by Acid-assisted Hydrothermal Treatment of Hexagonal-structured Nanocrystalline Titania/Cetyltrimethyammonium Bromide Nanoskeleton
Highly crystalline TiO2 nanostructures were prepared through a facile inorganic acid-assisted hydrothermal treatment of hexagonal-structured assemblies of nanocrystalline titiania templated by cetyltrimethylammonium bromide (Hex-ncTiO2/CTAB Nanoskeleton) as starting materials. All samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The influence of hydrochloric acid concentration on the morphology, crystalline and the formation of the nanostructures were investigated. We found that the morphology and crystalline phase strongly depended on the hydrochloric acid concentrations. More importantly, crystalline phase was closely related to the morphology of TiO2 nanostructure. Nanoparticles were polycrystalline anatase phase, and aligned nanorods were single crystalline rutile phase. Possible formation mechanisms of TiO2 nanostructures with various crystalline phases and morphologies were proposed
EFFECT OF Au DEPOSITION ON PHOTOCATALYTIC ACTIVITY OF ZnO NANOPARTICLES FOR CO OXIDATION
In this paper, pure and Au-deposited ZnO nanoparticles with different Au content were prepared and characterized. The effect of Au content on the PL properties and photocatalytic activity of CO oxidation was mainly investigated. The results showed that Au deposition can greatly decrease the intensity of PL and enhance the photocatalytic activity of CO oxidation, which may be attributed to the increased amounts of and the formation of O (or O-) on Au/ZnO surface.CO photocatalytic oxidation, Au/ZnO, photoluminescence (PL) spectra
REORGANIZATION OF BEHENIC ACID MONOLAYER ON MICA
Langmuir-Blogdett (LB) monolayers of behenic acid (BA) and cadmium behenic were prepared on mica surfaces by the vertical precipitation method. Atomic force microscopy (AFM) and lateral force microscopy (LFM) were used to study the morphologies of the films before and after reorganization and friction image. The LB films of fatty acid were found to self-organize into multilayers in water simply by the addition or removal of one layer of molecules, suggesting that the reorganization is a common phenomenon for monolayer on substrates in water conditions. It is considered that the H2O molecules in the first place interact with the BA amphiphilic molecules at the edge of the pinholes. The assembly of molecules at the edge of the pinholes changes with a little protuberance in the morphology. The reorganization extent was also relevant to the pH value of the water medium.Langmuir-Blogdett (LB) films, atomic force microscopy (AFM), molecular reorganization