Self-organised microdots formed by dewetting in a highly volatile liquid

• Published in: Journal of colloid and interface science 2012-07, Vol.378 (1), p.201-209
• Main Authors: Toth, Rita, Heier, Jakob, Tisserant, Jean-Nicolas, Anna, Enyedy Eva, Braun, Artur, Graule, Thomas
• Format: Article
• Language: English
• Subjects: Arrays; Chemistry; Contact; Crystal structure; Density; Dewetting; Droplets; Evaporation; Exact sciences and technology; ferric oxide; General and physical chemistry; heat treatment; Hexagonal and tetragonal order; Iron oxide microstructure; Liquids; Microdot; microstructure; Receding contact line; Self-organisation; silicon; solutes; Stick–slip motion
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2012.04.011

[Display omitted] ► Solvent evaporation induced dewetting leads to ordered microdots. ► Stick–slip motion and fingering instability of the contact line. ► Parameters affecting the size and order of the microdots are investigated. ► Size, density and shape of microdots are altered by using micro printed substrates. ► Fe2O3 micropatterns are obtained by thermal treatment. Dewetting induced self-organisation was used to prepare an ordered microstructure from a highly volatile liquid. Dewetting of an evaporating iron oxide precursor solute on silicon substrate resulted in arrays of microdots with nearly hexagonal and tetragonal symmetries. Ordered structures form either by stick–slip motion or fingering instability at the receding contact line of evaporating droplets. Subsequent thermal treatment at 550°C yields crystalline Fe2O3 microdots with a diameter range of 1–4μm. The size, density and shape of the microdots can be changed by using patterned substrates with different surface energies.