Structuring of Fluid Adlayers upon Ongoing Unimolecular Adsorption

Schaefer, C.

Abstract

Fluids with spatial density variations of single or mixed molecules play a key role in biophysics, soft matter, and materials science. The fluid structures usually form via spinodal decomposition or nucleation following an instantaneous destabilization of the initially disordered fluid. However, in practice, an instantaneous quench is often not viable, and the rate of destabilization may be gradual rather than instantaneous. In this work we show that the commonly used phenomenological descriptions of fluid structuring are inadequate under these conditions. We come to that conclusion in the context of surface catalysis, where we employ kinetic Monte Carlo simulations to describe the unimolecular adsorption of gaseous molecules onto a metal surface. The adsorbates diffuse at the surface and, as a consequence of lateral interactions and due to an ongoing increase of the surface coverage, phase separate into coexisting low- and high-density regions. The typical size of these regions turns out to depend much more strongly on the rate of adsorption than predicted from recently reported phenomenological models. We discuss how this finding contributes to the fundamental understanding of the crossover from liquid-liquid to liquid-solid demixing of solution-cast polymer blends.

Citation

Schaefer, C. (2018). Structuring of Fluid Adlayers upon Ongoing Unimolecular Adsorption. Physical Review Letters, 120(3), Article 036001. https://doi.org/10.1103/physrevlett.120.036001

• Journal Article Type: Article
• Acceptance Date: Oct 27, 2017
• Online Publication Date: Jan 19, 2018
• Publication Date: Jan 19, 2018
• Deposit Date: Feb 8, 2018
• Publicly Available Date: Feb 8, 2018
• Journal: Physical Review Letters
• Print ISSN: 0031-9007
• Electronic ISSN: 1079-7114
• Publisher: American Physical Society
• Peer Reviewed: Peer Reviewed
• Volume: 120
• Issue: 3
• Article Number: 036001
• DOI: https://doi.org/10.1103/physrevlett.120.036001
• Public URL: https://durham-repository.worktribe.com/output/1340085