title: Microwave frequency effect in the formation of Au nanocolloids in polar and non-polar solvents.
abstract: Given earlier observations that microwave frequencies can have a substantial effect on the photoactivity of a well-known photocatalyst (TiO(2)), in the synthesis of 3,6-diphenyl-4-n-butylpyridazine through a Diels-Alder process, and in the one-pot solvent-free synthesis of a room-temperature ionic liquid, we proceeded to examine the frequency effects of the 5.8 and 2.45 GHz microwave (MW) radiation in the synthesis of gold nanoparticles in non-polar media, such as oleylamine, which have a low dielectric constant (ε'), and we further examine differences in shape and size under otherwise identical temperature conditions when the synthesis of the gold nanoparticles was carried out in an ethylene glycol polar medium in the presence of polyvinylpyrrolidone. Whereas a change in microwave frequency from 2.45 to 5.8 GHz at equal microwave power levels led to the synthesis of gold nanoparticles in the non-polar media, a change in the microwave frequency had no effect on the size and shape of the gold nanoparticles synthesized in polar media for identical microwave power levels.
authors.affiliation: Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510. Japan. horikosi@rs.noda.tus.ac.jp
authors.forename: Satoshi
authors.initials: S
authors.lastname: Horikoshi
authors.forename: Hideki
authors.initials: H
authors.lastname: Abe
authors.forename: Takuya
authors.initials: T
authors.lastname: Sumi
authors.forename: Kanjiro
authors.initials: K
authors.lastname: Torigoe
authors.forename: Hideki
authors.initials: H
authors.lastname: Sakai
authors.forename: Nick
authors.initials: N
authors.lastname: Serpone
authors.forename: Masahiko
authors.initials: M
authors.lastname: Abe
mesh_terms: D003102:Colloids / Q000737:chemistry / Q000528:radiation effects; D006046:Gold / Q000737:chemistry* / Q000528:radiation effects*; D046911:Macromolecular Substances / Q000737:chemistry / Q000528:radiation effects; D008422:Materials Testing; D008872:Microwaves; D008968:Molecular Conformation / Q000528:radiation effects; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects* / Q000648:ultrastructure; D010316:Particle Size; D012997:Solvents / Q000737:chemistry / Q000528:radiation effects; D055672:Static Electricity; D013499:Surface Properties / Q000528:radiation effects
chemical_list: D003102:Colloids; D046911:Macromolecular Substances; D012997:Solvents; D006046:Gold