Work

Capillarity-driven assembly of colloidal microbullets at an air/water interface

Year: 2025

Type: article

Abstract: HYPOTHESIS: The shape anisotropy of colloids controls interparticle interactions at fluid interfaces, hence governing colloidal assembly. The preferred orientation of rod-like particles at flat interfaces is dependent on the specific particle shape, aspect ratio, and contact angles. EXPERIMENTS: Anisotropic bullet-shaped colloids are studied at an air/water interface with optical microscopy. The fractal dimension, as well as positional and orientational orders, are characterized. The deformation of the interface around a microbullet is evaluated. FINDINGS: The pronounced asymmetric interface distortion around microbullets leads to a strong capillary attraction. This attraction is dependent on orientation and results in preferred lateral particle interactions. A series of laterally aligned microbullets form smectic-like domains that subsequently attract each other, resulting in the development of a rigid gel-like monolayer. The arrangement of this monolayer strongly resembles a smectic-like order at short distances, while exhibiting disorder attributed to different domain orientations at larger distances.

Source: Journal of Colloid and Interface Science

DOI: 10.1016/j.jcis.2025.138200

Authors: Pedro Díaz-Leyva, Javier Cruz-Aparicio, Rodrigo Sánchez, Anna Kozina

Institutions: Universidad Autónoma Metropolitana, Universidad Nacional Autónoma de México

Language: English

Topic: Pickering emulsions and particle stabilization

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,470

Funders: Dirección General de Asuntos del Personal Académico, Universidad Nacional Autónoma de México, Universidad Autónoma Metropolitana unidad Iztapalapa