Adsorption energy of nano- and microparticles at liquid-liquid interfaces.
Langmuir
; 26(15): 12518-22, 2010 Aug 03.
Article
em En
| MEDLINE
| ID: mdl-20593775
ABSTRACT
We study experimentally the energy of adsorption, DeltaE, of nanoparticles and microparticles at the oil-water interface by monitoring the decrease of interfacial tension as the particles bind. For citrate-stabilized gold nanoparticles assembling on a droplet of octafluoropentyl acrylate, we find DeltaE = -5.1 k(B)T for particle radius R = 2.5 nm and DeltaE proportional, variant R(2) for larger sizes. Gold nanoparticles with (1-mercaptoundec-11-yl)tetra(ethylene glycol) ligand have a much larger binding energy (DeltaE = -60.4 k(B)T) and an energy barrier against adsorption. For polystyrene spheres with R = 1.05 microm, we find DeltaE = -0.9 x 10(6) k(B)T. We also find that the binding energy depends on the composition of the oil phase and can be tuned by the salt concentration of the nanoparticle suspension. These results will be useful for controlling the assembly of nanoparticles at liquid interfaces, and the method reported here should be broadly useful for quantitative measurements of binding energy.
Texto completo:
1
Bases de dados:
MEDLINE
Idioma:
En
Revista:
Langmuir
Assunto da revista:
QUIMICA
Ano de publicação:
2010
Tipo de documento:
Article
País de afiliação:
Estados Unidos