Real-Time Monitoring Distance Changes in Surfactant-Coated Au Nanoparticle Films upon Volatile Organic Compounds (VOCs)

MARÍA CELESTE DALFOVO; LISANDRO J. GIOVANETTI; JOSE M. RAMALLO-LÓPEZ; ROBERTO C. SALVAREZZA; FÉLIZ G. REQUEJO; FRANCISCO J. IBAÑEZ

AMER CHEMICAL SOC

Lugar: Washington; Año: 2015 p. 5098 - 5098

e explore into the role of the organic ligands composition surrounding Au nanoparticles (NPs) toward internanoparticles distance changes and film structure during vapor sensing by the use of in situ grazing-incidence small-angle X-ray scattering (GISAXS) and other relevant techniques. We observed distinct changes in core-to-core distance and film structure upon measured concentrations of polar ethanol (EtOH) and nonpolar toluene (Tol) vapors. As-formed tetraoctylammonium bromide (TOABr)-coated Au NPs (SNPs) film exhibited ∼0.4 nm core-to-core increase in distance and improved SNPs correlation upon 80% Tol. In the presence of EtOH, SNPs distance seems not to change and correlation critically diminishes, leading to an amorphous film. As-formed films were exchanged with nonanedithiol (NDT) and exposed to 100% Tol vapor. Interestingly, the incorporation of NDT increased distance between NPs and rendered film flexibility. It is determine that just a small number of S, from NDT ligand