| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2016) | |
| Thin Films | Tuesday Sessions |
| Session TF-TuM |
| Session: | Nanostructured Surfaces & Thin Films II |
| Presenter: | Chris Papadopoulos, University of Victoria, Canada |
| Authors: | R. Sapkota, University of Victoria, Canada C. Papadopoulos, University of Victoria, Canada |
| Correspondent: | Click to Email |
Nanostructured surfaces and thin films composed of nanoscale particles can be created using a variety of nanofabrication methods for applications in electronics, photonics, energy, biotechnology, etc. Generally, such nanostructures can take many forms depending on the various top-down to bottom-up fabrication methodologies [1]. Nanoscale grinding, or colloidal grinding, is a unique approach to nanoparticle thin film synthesis that can directly produce large amounts of nanoscale particles in an appropriate solvent without the use of complex chemical or physical processing. Planetary ball milling is typically used to grind a starting bulk powder into a nanoscale colloidal suspension suitable for thin film coating of various functional materials from solution. Efficient energy transfer during planetary ball motion leads to a fast and inexpensive process for the creation of nanostructured films. By adjusting the grinding parameters, the size and dispersion of the particles can be controlled and optimized for applications.
Here we describe results using the nanoscale grinding approach to fabricate multi-functional nanostructured thin film coatings. Nanogrinding allows tunability of film properties that can lead to novel functions depending on the particular combination of material, solvent and nanoparticle geometries/dimensions used. These unique abilities produce a general solution-based processing approach for thin film surface coatings and devices (including non-planar geometries).
Nanostructured thin films based on grinding high-purity powders (Si and TiSi) and characterization via electron microscopy, scanning probe, electronic transport and contact angle measurements are presented. Zirconia beads in a planetary ball mill with readily available powders initially consisting of ~10-50 micron particles in solvent were used. Grinding speeds and times varied between approx. 300-1000 rpm and 10-250 minutes, respectively. The resulting colloidal dispersions are deposited on a substrate for analysis. As grinding time is increased, the particles and films display good uniformity with sizes reaching below 100 nm. Both electrical conductance and contact angle could be tuned over a wide range depending on grinding conditions thereby creating unique multi-functional nanostructured materials and films. We also discuss preliminary results on optical and photocatalytic properties of the nanostructured surfaces. Thin films created via nanogrinding possess unique and varied electrical, optical and mechanical properties, which can be used to create advanced materials and devices.
[1] C. Papadopoulos, “Nanofabrication: Principles and Applications”, Springer, 2016.