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Author: Kraus, Tobias × End date: 2024 × DDC: 530 × Publisher: Washington D.C. : American Chemical Society × WGL Institute: INM ×

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    Self-assembly of gold nanoparticles at the oil-vapor interface: from mono- to multilayers
    (Washington D.C. : American Chemical Society, 2014) Born, Philip; Schön, Volker; Blum, Susanne; Gerstner, Dominik; Huber, Patrick; Kraus, Tobias
    Alkylthiol-coated gold nanoparticles spontaneously segregate from dispersion in toluene to the toluene-vapor interface. We show that surface tension drops during segregation with a rate that depends on particle concentration. Mono- and multilayers of particles form depending on particle concentration, time, and temperature. X-ray reflectometry indicates fast monolayer formation and slow multilayer formation. A model that combines diffusion-limited segregation driven by surface energy and heterogeneous agglomeration driven by dispersive van der Waals particle interactions is proposed to describe film formation.
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    Dense arrays of uniform submicron pores in silicon and their applications
    (Washington D.C. : American Chemical Society, 2015) Brodoceanu, Daniel; Elnathan, Roey; Prieto-Simón, Beatriz; Delalat, Bahman; Guinan, Taryn M.; Kroner, Elmar Karsten; Voelcker, Nicolas H.; Kraus, Tobias
    We report a versatile particle-based route to dense arrays of parallel submicron pores with high aspect ratio in silicon, and explore the application of these arrays in sensors, optics, and polymer micropatterning. Polystyrene (PS) spheres are convectively assembled on gold-coated silicon wafers and sputter-etched, resulting in well-defined gold disc arrays with excellent long-range order. The gold discs act as catalysts in Metal-Assisted Chemical Etching (MACE), yielding uniform pores with straight walls, flat bottoms and high aspect ratio. The resulting pore arrays can be used as robust antireflective surfaces, in biosensing applications, and as templates for polymer replica molding.