Fabrication of LDPE Superhydrophobic Surface by Stretching Controlled Micromolding

PDMS templates were prepared by replica molding against fresh lotus leaves. Then lowdensity polyethylene (LDPE) was melted and pressed onto the featured surface of the PDMS template in a vacuum oven. After cooling to room temperature and being peeled off from the templates, polyethylene films with superhydrophobic surface were created. FESEM imaging shows that the superhydrophobic surface is consist of slim and high micro-papillas (about 30 μm). The contact angle is 154°±3.5° and the water drops can easily skip down. While surface of LDPE films micromolded in general oven possess much lower papillas (8-10 μm) and the contact angle is 137°±2.7°. The height of lower papillas approaches the depth of microholes on PDMS templates demonstrating the higher papillas have been stretched longer from the holes of the template during separating operation.