Rate-dependent interface capture beyond the coffee-ring effect

• Published in: Scientific reports Vol. 6; no. 1; p. 24628
• Main Authors: Li, Yanan, Yang, Qiang, Li, Mingzhu, Song, Yanlin
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 19-04-2016; Nature Publishing Group
• Subjects: 119/118; 639/301; 639/638/440; Coffee; Drying; Evaporation; Fabrication; Humanities and Social Sciences; Morphology; multidisciplinary; Printing; Science; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep24628

The mechanism of droplet drying is a widely concerned fundamental issue since controlling the deposition morphology of droplet has significant influence on printing, biology pattern, self-assembling and other solution-based devices fabrication. Here we reveal a striking different kinetics-controlled deposition regime beyond the ubiquitous coffee-ring effect that suspended particles tend to kinetically accumulate at the air-liquid interface and deposit uniformly. As the interface shrinkage rate exceeds the particle average diffusion rate, particles in vertical evaporation flow will be captured by the descending surface, producing surface particle jam and forming viscous quasi-solid layer, which dramatically prevents the trapped particles from being transported to drop edge and results in uniform deposition. This simple, robust drying regime will provide a versatile strategy to control the droplet deposition morphology, and a novel direction of interface assembling for fabricating superlattices and high quality photonic crystal patterns.