title: Optical changes and writing on hydrotalcite supported gold nanoparticles.
abstract: Gold nanoparticles (AuNP) incorporated into hydrotalcite (HT), provide an interesting type of pigment in which temperature can modulate the plasmon resonance and the aggregation phenomenon. As inferred from microscopy techniques, the preferential binding sites are located at the border of the HT external basal surface, leading to aggregates of gold nanoparticles displaying characteristic plasmon resonance and interference bands around 520 and 700 nm, respectively. The thermally induced color changes in the HT-supported gold material arise from the competition between of nanoparticles aggregation and fusion processes, as characterized by TEM and STM. A laser beam can also induce such changes, allowing the writing of optical information on this type of material.
authors.affiliation: Instituto de Quimica, Universidade de S. Paulo, Caixa Postal 26077 CEP 05513-970, São Paulo, SP, Brazil.
authors.forename: Leonardo S
authors.initials: LS
authors.lastname: Bonifacio
authors.forename: Claudia R
authors.initials: CR
authors.lastname: Gordijo
authors.forename: Vera R L
authors.initials: VR
authors.lastname: Constantino
authors.forename: Denise O
authors.initials: DO
authors.lastname: Silva
authors.forename: Pedro K
authors.initials: PK
authors.lastname: Kiyohara
authors.forename: Koiti
authors.initials: K
authors.lastname: Araki
authors.forename: Henrique E
authors.initials: HE
authors.lastname: Toma