(65au) Preparation of Superhydrophobic Polymethylene Films

Some plants such as Lotus (Nelumbo nucifera) have been known to exhibit special self cleaning properties termed ?Lotus Effect?, in which dirt is picked up from the surface when the surface leave comes in contact with water droplets. Previous studies have demonstrated that the combination of low surface energy materials with nano- and micrometer scale topography is responsible for this behavior. This superhydrophobic effect has applications in fields such as micro fluidics and water repellent paints and fabrics. Here we described the preparation of low energy surface energy materials with nano- and micrometer scale features using a combination of soft lithographic patterning and surface-initiated polymerization. Polymethylene films were synthesized in the experiment using no specific topographical design. For this method, necessary surface topography is produced after the films are allowed to polymerize past thickness of 2500-3000 nm. Soft lithography patterning method and no topographical design method were compared to improve the superhydrophobicity of the films. Particular emphasis was placed on soft lithography patterning of polymethylene film to achieve the optimal surface roughness to produce the best superhydrophobic films. It has been proven that with soft lithography patterning, superhydrophobic polymethylene films can be produced with film thickness of 1500-2000 nm.