Tunable optical matter: electrostatic repulsion modulates near- and far-field gold nanoparticle arrangements

The dynamics and equilibrium configurations of immersed optically-bound particles are complex phenomena involving several physical mechanisms such as optical forces, electrostatic interactions, and fluid dynamics. In this work, we unravel, using experiments and numerical simulations, the key role pl...

ver descrição completa

Detalhes bibliográficos
Autores: Chen, Jui-Kai, Olmos Trigo, Jorge, Louis, Boris, Huang, Chih-Hao, Rocha, Susana, Masuhara, Hiroshi, Hofkens, Johan, Delgado-Buscalioni, Rafael, Bresolí-Obach, Roger, Marqués, Manuel I., Meléndez, Marc
Tipo de documento: artigo
Data de publicação:2026
País:España
Recursos:Varias* (Consorci de Biblioteques Universitáries de Catalunya, Centre de Serveis Científics i Acadèmics de Catalunya)
Repositório:Recercat. Dipósit de la Recerca de Catalunya
OAI Identifier:oai:dnet:recercat____::4b6b89c62fb994150242342d416c9138
Acesso em linha:https://hdl.handle.net/20.500.14342/6179
https://doi.org/10.1039/D5NA00926J
Access Level:Acceso aberto
Palavra-chave:Electrostatics
Optical binding
Gold nanoparticles
Or
Nanopartícules
Electroestàtica
535
537
Descrição
Resumo:The dynamics and equilibrium configurations of immersed optically-bound particles are complex phenomena involving several physical mechanisms such as optical forces, electrostatic interactions, and fluid dynamics. In this work, we unravel, using experiments and numerical simulations, the key role played by short-range electrostatic forces. The repulsive interaction among gold nanoparticles is adjusted by changing the salt concentration. When the electrostatic interaction is reduced, near-field optical binding with particles oriented along the polarization direction is promoted, while, for low values of the salt concentration, inter-particle repulsion induces far-field (FF) optical binding configurations oriented perpendicular to the polarization. The importance of electrostatic force is confirmed by a theoretical model in which the repulsive effect is explicitly tuned. The numerical results reproduce the measured particle configurations and highlight the dominant role of electrostatic interactions, particularly in FF optical binding configurations.