Self-assembled nanoparticle-coated interfaces: Capillary pressure, shell formation and buckling.

Qi Liu, Z Sun, J Carlos Santamarina

Research output: Contribution to journalArticlepeer-review

6 Scopus citations


HYPOTHESIS:Particle accumulation at liquid-liquid or liquid-gas interfaces can significantly alter capillary behavior and give rise to unusual interfacial phenomena including the asymmetric macroscopic mechanical response of the interface. EXPERIMENTS:This study explores the accumulation of cetyltrimethylammonium bromide-modified nanoparticles at fluid interfaces and the subsequent mechanical response of nanoparticle-coated droplets during contraction and expansion. Droplet tests involve the simultaneous recording of the droplet shape and the capillary pressure. Complementary single-pore experiments examine the response of particle-coated interfaces as they traverse a pore constriction. FINDINGS:Interfaces promote order. The time-dependent nanoparticle accumulation at the interface is diffusion-controlled. The nanoparticle coated droplets can sustain negative capillary pressure before they buckle. Buckling patterns strongly depend on the boundary conditions: non-slip boundary conditions lead to crumples while slip boundary conditions result in just a few depressions. The particle-coated interface exhibits asymmetric behavior in response to particle-level capillary forces: an "oil droplet in a nanofluid bath" withstands a significantly higher capillary pressure difference than a "nanofluid droplet in an oil bath". A first-order equilibrium analysis of interaction forces explains the asymmetric response. Single-constriction experiments show that the formation of particle-coated interfaces has a pronounced effect on fluid displacement in porous media.
Original languageEnglish (US)
Pages (from-to)251-261
Number of pages11
JournalJournal of colloid and interface science
StatePublished - Aug 11 2020

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: Support for this research was provided by the KAUST endowment. G. Abelskamp edited the manuscript. We are grateful to the anonymous reviewers for their detailed reviews and insightful observations.


Dive into the research topics of 'Self-assembled nanoparticle-coated interfaces: Capillary pressure, shell formation and buckling.'. Together they form a unique fingerprint.

Cite this