The influence of bromine adsorption on copper electrodeposition on a polycrystalline gold electrode modified with self-assembled monolayers (SAMs) has been investigated by chronoamperometry and cyclic voltammetry. It was found that the deposition potential of copper was shifted negatively due to the SAMs. The hydrogen bond interaction between w-carboxyl thiols decreased the defect density of the SAMs and significantly retarded the deposition of copper. The presence of bromide anions also shifted the potential more negatively through adsorption into the defects of SAMs.

The initial growth process of silver nanoparticles on highly oriented pyrolytic graphite (HOPG) and amorphous carbon (a-C) was studied. Scanning tunneling microscopy was used for analysis of the nanoparticles formed on HOPG. Transmission electron microscopy was employed to study the growth procedure on a-C. The number densities (Dn) of silver nanoparticles on both HOPG and a-C remain constant at a very early stage, then both decrease with deposition time and have a saturated value. The Dn decrease suggests migration followed by impingement. We found evidence of migration of 5nm particles on a-C. Interpretations are given to explain the impingement and shape change of the silver nanoparticles.

Binary monolayers comprised of mercaptopyrimidine (MP) and 1-dodecanethiol (C12SH) in varying ratios were prepared on gold surfaces by self-assembly and then characterized using reflection absorption FTIR spectroscopic (RA-IR), electrochemical, and wettability measurements. The RA-IR results revealed that the coverage of MP in the mixed monolayer is controlled by its composition in solution. The adsorption of mixed monolayers appears to be kinetically controlled. The wettability of mixed monolayers indicated that the surface fraction of C12SH exposed to the probe liquid exceeded that of its mole fraction in the monolayer. Electrochemical measurements demonstrated that the permeabilities of various quinone probes into the mixed self-assembled monolayers (SAMs) were dominated by their geometry. The origination of the geometrydependent permeability of probes is believed to be related to the average size of MP domain in SAMs.

Porous aluminum oxide membranes with pore diameters smaller than 20nm were prepared by anodization of aluminum. Using these porous membranes as a template, we fabricated uniform gold cylinder arrays by electrodeposition of gold into the pores. All cylinders in the array were parallel, with their long axes perpendicular to the surface of the template. Electron microscopy, including transmission electron microscopy (TEM) and scanning electron microscopy (SEM), were employed to characterize the morphology of the templates and the fabricated nanometer scale of cylinder arrays. The extinction spectra of the arrays along the longer axes showed that the extinction maximal (λmax) shifted to a short wavelength and strengthened when the aspect ratio (l=d) of the cylinders increased. The dependence of the maximal (λmax) on the size was explained qualitatively by using the approximate dynamical Maxwell-Garnett model, and the calculated results were compared with the experimental ones.

Uniform arrays of Fe nanowires were prepared by electrochemical deposition of iron into nanoporous anodic aluminum oxide films. The microstructure and crystal structures of the nanowires were studied by transmission electron microscopy and electron diffraction. It was found that each nanowire looked like a chain of dots and each dot in the chain was supposed to be a single crystal of a-Fe. Each dot was shown to be a single magnetic domain. The magnetic properties of a uniform array of Fe nanowires and the magnetization reversal in a Fe nanowire were investigated by Mossbauer spectroscopy and vibrating sample magnetometry, which demonstrated that the film of Fe nanowires in alumina had superior perpendicular magnetic characteristics. The magnetic studies also revealed that the moments of each single domain dot were oriented along the chain. Experimental results could be interpreted by the reversal model of ''chains of spheres'' with the symmetric fanning mechanism.

2,2,6,6-Tetramethyl-4-hydroxypiperidine-1-oxyl (TMHPO) shows catalytic electroactivity in homogeneous oxidation of benzoyl hydrazine (BH) on a glassy carbon electrode. The catalytic current is affected by the concentration of TMHPO and the pH of the solution. A possible catalytic reaction mechanism is proposed and a non-toxic, convenient method for the determination of BH in the concentration range 1

Highly ordered anodic alumina oxide (AAO) membranes with a diameter of about 50 nm are prepared by two-step anodization. Cobalt nanowires were obtained by ac electro-deposition of Co2+ into the pore of AAO membranes. Vibrating sample magnetometer (VSM) results show that such a sample has highly perpendicular anisotropy properties. Here, we first use magnetic force microscopy (MFM) to obtain a fine image of magnetic domain structure in Co/AAO film successfully. MFM images show that each as-prepared nanowire in the membrane show single domain structure. The nearest neighbor bits have opposite magnetization. The magnetic moment was aligned in the same direction after the sample was magnetized under a 1 T external field. Due to its high bit density (up to 100 Gbits/in.2), such a material may be used as high-density perpendicular recording quantum magnetic disks (QMD).

A new type of magnetic polymer microsphere containing acylhydrazine groups on the surface was synthesized. They can be reacted with formaldehyde to produce an electroactive adduct. Reduction of these derivatives following aggregation on a magnetic electrode is possible and is effective in the indirect determination of formaldehyde. The experimental conditions and electrode structure are discussed. Under the optimum conditions, it was found that the peak potential (Ep) of formaldehyde is 21.01V (vs. Ag/AgCl). Formaldehyde in the range 1-1000mg l21 can be determined. The detection limit for formaldehyde is 0.3mg l21 and the relative standard deviation for the determination of 100mg l21 formaldehyde was 2.26%. The method was applied to the determination of formaldehyde in environmental samples with satisfactory results.