SYNTHESIS AND PROPERTIES OF LIPOIC ACID STABILIZED GOLD NANOCLUSTERS

Disulfide lipoic acid was used to synthesize new aqueous soluble gold nanomaterials. The first one is an ultra-small plasmonic nanoparticle displaying a weak plasmonic band at 520 nm. At the transition zone between larger metallic nanoparticles and smaller non-metallic nanoclusters, intriguing electrochemical and optical features were observed. The other cluster is a new molecular-like nanocluster with unique optical features. Distinct UV-visible absorption bands were observed corresponding to discrete energy states/orbitals along with a weak photoluminescence if ultracentrifuge purification is adopted. Dialysis purification yielded a tenfold increase in photoluminescence while the absorption bands diminish. This transition is attributed to the gradual oxidation of some of the sulfur atoms at the core-ligand interface. Annealing with a known amount of excess thiol is shown to expedite and better control the transitions observed through the synthesis and purification along with yielding an enhancement of the electrochemiluminescence by more than ten folds

Study of Multiphase Networks, Noise Reduction for DC-DC Converters, and Stability Test for Electronic Systems

学位記番号：理工博甲7

THE INFRASTRUCTURE AND ENVIRONMENT IN THE OLD TENEMENTS IN HANOI

Joint Research on Environmental Science and Technology for the Eart