Interactions between polystyrene particles with diameters of several tens to hundreds of micrometers at the oil-water interface.
J Colloid Interface Sci
; 560: 838-848, 2020 Feb 15.
Article
em En
| MEDLINE
| ID: mdl-31708257
ABSTRACT
HYPOTHESIS:
The charged spherical colloidal particles at the fluid-fluid interface experience considerably strong and long-ranged electrostatic and capillary interactions. The contribution of capillary force becomes more significant as the particle size increases beyond a certain limit. The relative strengths of the two competing interactions between the spherical polystyrene particles at the oil-water interface are quantified depending on their size. EXPERIMENTS The studied particles, obtained using the microfluidic method, have diameters of tens to hundreds of micrometers. The scaling behaviors of the commercially available colloidal particles with diameters of ~3⯵m are also compared. An optical laser tweezer apparatus is used to directly or indirectly measure the interparticle force. Subsequently, the capillary force that can be attributed to the gravity-induced interface deformation and contact line undulation is calculated and compared with the measured interaction force.FINDINGS:
Regardless of the particle diameter (~3-330⯵m), the measured force is observed to decay as r-4, where r denotes the center-to-center separation, demonstrating that the dipolar electrostatic interaction is important and that the gravity-induced capillary interaction is negligible. Furthermore, numerical calculations with respect to the undulated meniscus confirm that the magnitude of capillary interaction is significantly smaller than that of the measured electrostatic interaction.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
J Colloid Interface Sci
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Coréia do Sul