Controlling the micro/nanostructure of self-cleaning polymer coating

Polypropylene bio-mimic self-cleaning surfaces with porous micro-nano-binary morphology structures were prepared by a simple casting method. The influence of the cooling process and solvent composition on water contact angle, sliding angles and self-cleaning properties has been investigated. Detailed SEM morphology studies revealed that the polymer used in this work is commercial-grade granular low-density polyethylene (LDPE) forms petal-like crystalline, which are of micrometer scale in length and nanometer scale in thickness. The nano-crystallines on the surface represent a porous three-dimensional micro-nano-binary structure. It was found that a compromise to the film porosity and crystal nano structure is essential for achieving a satisfied self-cleaning surface. Under optimum condition, a water contact angle of 152.2°, and a sliding angle of 1.7° can be obtained using this simple method.