I  U  P  A  C






News & Notices

Organizations & People

Standing Committees

Divisions

Projects

Reports

Publications
..CI
..PAC
..Macro. Symp.

..Books
..Solubility Data

Symposia

AMP

Links of Interest

Search the Site

Home Page

 

Pure Appl. Chem. Vol. 72, Nos. 1-2, pp. 91-99, 2000

Special Topic Issue on the Theme of
Nanostructured Systems

 

Phototransformation of Alkanethiol-derivatized Noble Metal Nanoparticle

Chil Seong Ah, Hyouk Soo Han, Kwan Kim, and Du-Jeon Jang*

*School of Chemistry and Center for Molecular Catalysis, Seoul National University, Seoul 151-742, Korea

Abstract: Photon-initiated shape transformation of n-alkanethiol-derivatized noble metal nanoparticles has been studied with variations of metal, alkanethiol, and solvent. Silver nanoparticles undergo fragmentation upon irradiation while gold ones barely do. Silver/gold composite particles follow the case of silver with a reduced efficiency. The efficiency decreases as alkanethiol length or solvent dipole moment increases. Following the conduction of thermalized photon energy, alkanethiol can dissociate in a period of heat dissipation, and some of dethiolated particles fragment within the recombination time. Prior to the thermal conduction, shape transformation via melt and vaporization also occurs for both metals but this effect is less apparent for silver because of more notable fragmentation followed. The difference in the transformation of two metals is ascribed to the differences in work function, oxidation potential, atomization enthalpy, and particle size. Smaller fragmentation efficiency with more polar solvent or longer alkanethiol is attributed mainly to relatively smaller dissociation rate compared with heat dissipation rate.

Back to Contents for access to full text


Page last modified 5 May 2000.
Copyright © 2000 International Union of Pure and Applied Chemistry.
Questions or comments about IUPAC, please contact, the Secretariat.
Questions regarding the website, please contact web manager.