Foam-Film-Stabilized Liquid Bridge Networks in Evaporative Lithography and Wet Granular Matter

Abstract

Evaporative lithography using latex particle templates is a novel approach for the self-assembly of suspension-dispersed nanoparticles into ordered microwire networks. The phenomenon that drives the self-assembly process is the propagation of a network of interconnected liquid bridges between the template particles and the underlying substrate. With the aid of video microscopy, we demonstrate that these liquid bridges are in fact the border zone between the underlying substrate and foam films vertical to the substrate, which are formed during the evaporation of the liquid from the suspension. The stability of the foam films and thus the liquid bridge network stability are due to the presence of a small amount of surfactant in the evaporating solution. We show that the same type of foam-film-stabilized liquid bridge network can also propagate in 3D clusters of spherical particles, which has important implications for the understanding of wet granular matter.

Acoustic separation of oil droplets, colloidal particles and their mixtures in a microfluidic cell

“…In this case, the emulsion was stabilized by adding to the water phase 1×10 -3 wt % of Zonyl FSN (DuPont) which is a nonionic fluorosurfactant that modifies the interfacial energies at very low concentrations [24]. In preparation of the perfluorohexane emulsions, we used the same mixing protocol as that for the fine dodecane droplets emulsion given above.…”

Hierarchical Assembly of Plasmonic Nanoparticles*

“…Vakarelski et al demonstrated formation of gold wires in am acroscale connected network using ac olloidal mask of latex beads. [36][37]45] Importantly,t he addition of surfactant was important to stabilize the liquid film and allow the formation of the plasmonic network upon drying (Figure 4A,B). In order to improvet he reproducibility and versatility,t he authors used ap hotoresist as am askt od irect the drying of the goldc olloid ( Figure 4C).…”

Colloidal crystals and water: Perspectives on liquid–solid nanoscale phenomena in wet particulate media

“…Other applications of CCs as membranes [55], nanostructured platforms [56,57] and templates [58,59] depend on flow and diffusion processes of liquids in nanoconfinements such as the opal interstices. Any advance in the comprehension of these features is also beneficial for fields such as colloidal assembly or capillary/evaporation-assisted lithography [60,61]. drophilicity due to the presence of a large number of −OH groups (silanols) at its surface [64].…”

“…Even considering surface effects, enhanced condensation would occur only very close to the contact between spheres and cannot account for the broad neck azimuthal radii (R ~ 65 nm in 335-nm spheres and, from Figure 9b, R ~ 200 nm in 900-nm beads). Actually, it is typically found that liquid concentrates at contacts, like between touching large-sized spheres [60,80,81,135]. Such large menisci are habitually assumed to be formed by capillary suction from the surrounding wetting film into the gap, as long as there exists enough liquid on the grain to allow flow [7,8,47,136].…”