Low-density polyethylene (LDPE) surface with a wettability gradient by tuning its microstructures

We describe an interesting approach to the fabrication of wettability gradients from hydrophobicity to superhydrophobicity in low-density polyethylene (LDPE) films by first forming high porosity surfaces and placing the specimens onto linear temperature gradients. While the polymer chosen for the study is non-polar, its microporous layer provides sufficient superhydrophobicity. Lateral gradient heating of the layer results in partial melting of the polymer and correspondingly decreases porosity thus decreasing hydrophobicity.