23 research outputs found
In situ SU-8 silver nanocomposites
Nanocomposite materials containing metal nanoparticles are of considerable interest in photonics and optoelectronics applications. However, device fabrication of such materials always encounters the challenge of incorporation of preformed nanoparticles into photoresist materials. As a solution to this problem, an easy new method of fabricating silver nanocomposites by an in situ reduction of precursors within the epoxy-based photoresist SU-8 has been developed. AgNO3 dissolved in acetonitrile and mixed with the epoxy-based photoresist SU-8 forms silver nanoparticles primarily during the pre- and post-exposure soft bake steps at 95 °C. A further high-temperature treatment at 300 °C resulted in the formation of densely homogeneously distributed silver nanoparticles in the photoresist matrix. No particle growth or agglomeration of nanoparticles is observed at this point. The reported new in situ silver nanocomposite materials can be spin coated as homogeneous thin films and structured by using UV lithography. A resolution of 5 µm is achieved in the lithographic process. The UV exposure time is found to be independent of the nanoparticle concentration. The fabricated silver nanocomposites exhibit high plasmonic responses suitable for the development of new optoelectronic and optical sensing devices
Towards Coated Nano-Gold Particles as Non-Reactive Tracers in Coated nZVI for In-Situ Remediation
Towards nano-gold particles as tracers to use in coinjection with reactive nZVI for in-situ remediation of DNAPL source zones
Mobility of electrostatically and sterically stabilized gold nanoparticles (AuNPs) in saturated porous media
Blueshift of the surface plasmon resonance in silver nanoparticles studied with EELS
We study the surface plasmon (SP) resonance energy of isolated spherical Ag
nanoparticles dispersed on a silicon nitride substrate in the diameter range
3.5-26 nm with monochromated electron energy-loss spectroscopy. A significant
blueshift of the SP resonance energy of 0.5 eV is measured when the particle
size decreases from 26 down to 3.5 nm. We interpret the observed blueshift
using three models for a metallic sphere embedded in homogeneous background
material: a classical Drude model with a homogeneous electron density profile
in the metal, a semiclassical model corrected for an inhomogeneous electron
density associated with quantum confinement, and a semiclassical nonlocal
hydrodynamic description of the electron density. We find that the latter two
models provide a qualitative explanation for the observed blueshift, but the
theoretical predictions show smaller blueshifts than observed experimentally.in
a homogeneous medium.Comment: 7 pages including 2 figures. S.R. and N.S. contributed equally.
Accepted for Nanophotonics (De Gruyter,
http://www.degruyter.com/view/j/nanoph