Characterization of citrates on gold and silver nanoparticles.

In this paper, we report different coordinations of citrates on gold (AuNP) and silver (AgNP) nanoparticles, as determined using Fourier transform infrared spectroscopy (FTIR) and molecular orbital (MO) calculations. AuNPs and AgNPs are found to have completely different interactions with the carboxylate anchoring groups, as indicated by their unique asymmetric stretching vibrations in the FTIR spectra. The ν(as) (COO(-)) of citrate exhibits a high-frequency shift resulting from the formation of a unidentate coordination on AuNPs, whereas this vibration exhibits a low-frequency shift as a result of ionic bond formation on AgNPs, as predicted from the MO calculations of the corresponding metal complex salts.

Ag nanoparticle sheet as a marker of lateral remote photocatalytic reactions.

The lateral remote photocatalytic activity of TiO(2) nanotubes fabricated by anodic oxidation, was characterized by use of a 'silver nanosheet' as a marker. The silver nanosheet is a two-dimensional crystalline film composed of myristate-capped silver nanoparticles (d = 5 nm), which has a sharp localized plasmon absorption band at lambda(max) = 470 nm. A quartz substrate was coated with TiO(2) nanotubes to a coverage of 10% and then covered with a silver nanosheet.

The PDMS-based microfluidic channel fabricated by synchrotron radiation stimulated etching.

Micro pattern on PDMS surface has been achieved by using synchrotron radiation (SR) stimulated etching. The experimental results indicated that SR stimulated etching has many advantages, such as extremely high etching rate (as large as 40-50 mum per 10 min), area-selectivity and anisotropy at room temperature, high spatial resolution. Combining the SR stimulated etching with photolithography, a PDMS-based microfluidic channel was obtained.