Evolution and Environmental Degradation of Superhydrophobic Aspen and Black Locust Leaf Surfaces

• Main Author: Tranquada, George Christopher
• Other Authors: Erb, Uwe
• Language: en_ca
• Published: 2013
• Subjects: Superhydrophobic surfaces; environmental degradation; evolution of superhydrophobic leaves; dual-scale roughness; wear and erosion of leaf surfaces; aspen and black locust leaf surfaces; evolution of leaf surfaces; superhydrophobic leaf surfaces; cuticular damage; micro and nano-scale roughness; biomimetics; nanomaterials; epicuticular wax morphologies; sensitivity to environmental stresses; micro-structured materials; nano-structured materials; nano-scale platelets; materials science; nanotechnology; materials engineering; 0794
• Online Access: http://hdl.handle.net/1807/35697

The current study is focused on the characterization of four natural leaf species (quaking, bigtooth and columnar european aspen as well as black locust) possessing a unique dual-scale cuticle structure composed of micro- and nano-scale asperities, which are able to effectively resist wetting (superhydrophobic), characteristic of The Lotus Effect. Scanning Electron Microscopy (SEM) was used to track the growth and evolution of their distinctive nano-scale epicuticular wax (ECW) morphologies over one full growing season. In addition, the stability of their superhydrophobic property was tested in various environments. It was determined that the long-term stability of these surfaces is tentatively linked to various environmental stress factors. Specifically, a combination of high temperature and humidity caused the degradation of nano-scale asperities and loss of the superhydrophobic property. The dual-scale surface structure was found to provide a suitable template for the design of future superhydrophobic engineering materials.