Evaporative gold nanorod assembly on chemically stripe-patterned gradient surfaces

JOURNAL OF COLLOID AND INTERFACE SCIENCE

卷:449

Article

Ahmad, Imtiaz¹  Jansen, H. Patrick¹  van Swigchem, Jeroen¹  Ganser, Christian^2,3  Teichert, Christian²  Zandvliet, Harold J. W.¹  Kooij, E. Stefan¹ 

[1] Univ Twente, MESA Inst Nanotechnol, Phys Interfaces & Nanomat, NL-7500 AE Enschede, Netherlands

[2] Univ Leoben, Inst Phys, A-8700 Leoben, Austria

[3] Graz Univ Technol, Christian Doppler Lab Surface Chem & Phys Fundame, A-8010 Graz, Austria

关键词: Gold nanorods;    Directional wetting;    Evaporative assembly;   

DOI  :  10.1016/j.jcis.2014.12.067

来源: Elsevier

【 摘 要 】

Experimentally we explore the potential of using pre-defined motion of a receding contact line to control the deposition of nanoparticles from suspension. Stripe-patterned wettability gradients are employed, which consist of alternating hydrophilic and hydrophobic stripes with increasing macroscopic surface energy. Nanoparticle suspensions containing nanorods and nanospheres are deposited onto these substrates and left to dry. After moving over the pattern and evaporation of the solvent, characteristic nanoparticle deposits are found. The liquid dynamics has a pronounced effect on the spatial distribution. Nanoparticles do not deposit on the hydrophobic regions; there is high preference to deposit on the wetting stripes. Moreover, the fact that distributed nanoparticle islands are formed suggests that the receding of the contact line occurs in a stick-slip like fashion. Furthermore, the formation of liquid bridges covering multiple stripes during motion of the droplet over the patterns is modeled. We discuss their origin and show that the residue after drying, containing both nanoparticles and the stabilizing surfactant, also resembles such dynamics. Finally, zooming into individual islands reveals that highly selective phase separation occurs based on size and shape of the nanoparticles. (C) 2014 Elsevier Inc. All rights reserved.

【 授权许可】

Free