title: Understanding the self-assembly of charged nanoparticles at the water/oil interface.
abstract: We present a thermodynamic evaluation of the self-assembly of charged nanometer-sized particles at the water/oil interface. The chemical potentials of the nanoparticles in the bulk (aqueous) phase and at the water/oil interface are calculated taking into account interfacial energies, van der Waals interactions, and electrostatic repulsions. An isotherm of the interfacial particle density as a function of the surface charge density on the particles is obtained and compared with experimental results on gold and CdTe nanoparticles self-assembled at the water/heptane interface. Our model provides a semi-quantitative explanation for the spontaneous self-assembly of several types of metallic and semiconducting charged nanoparticles upon reduction of their surface charge.
authors.affiliation: Max Planck Institute of Colloids and Interfaces, Potsdam, Germany.
authors.forename: François
authors.initials: F
authors.lastname: Reincke
authors.forename: Willem K
authors.initials: WK
authors.lastname: Kegel
authors.forename: Hao
authors.initials: H
authors.lastname: Zhang
authors.forename: Marc
authors.initials: M
authors.lastname: Nolte
authors.forename: Dayang
authors.initials: D
authors.lastname: Wang
authors.forename: Daniel
authors.initials: D
authors.lastname: Vanmaekelbergh
authors.forename: Helmuth
authors.initials: H
authors.lastname: Möhwald
mesh_terms: D005898:Glass / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D006536:Heptanes / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D018613:Microscopy, Confocal / Q000379:methods; D053758:Nanoparticles / Q000737:chemistry*; D009821:Oils; D020349:Surface Plasmon Resonance / Q000379:methods; D013499:Surface Properties; D014867:Water
chemical_list: D006536:Heptanes; D009821:Oils; D014867:Water; D006046:Gold