Conical Nanotubes Synthesized by Atomic Layer Deposition of Al2O3, TiO2, and SiO2 in Etched Ion-Track Nanochannels
Nils Ulrich, Anne Spende, Loïc Burr, Nicolas Sobel, Ina Schubert, Christian Heß, C. Trautmann, María Eugenia Toimil‐Molares
Abstract
Etched ion-track polycarbonate membranes with conical nanochannels of aspect ratios of ~3000 are coated with Al2O3, TiO2, and SiO2 thin films of thicknesses between 10 and 20 nm by atomic layer deposition (ALD). By combining ion-track technology and ALD, the fabrication of two kinds of functional structures with customized surfaces is presented: (i) arrays of free-standing conical nanotubes with controlled geometry and wall thickness, interesting for, e.g., drug delivery and surface wettability regulation, and (ii) single nanochannel membranes with inorganic surfaces and adjustable isoelectric points for nanofluidic applications.