Nanostructured and chemically modified hydrophobic polyolefin surfaces

Hydrophobic polyolefin (PO) surfaces were prepared by perfluoropolyether (PFPE) blending and nanostructuring. Surface modifications were done by injection molding. Two high-density polyethylenes and polypropylene were melt blended with 2.0 wt.% of PFPE. Both polyethylenes formed blends with PFPE and showed improved hydrophobicity. For nanostructuring, self-ordered nanoporous mold inserts were fabricated by anodizing aluminum in polyprotic acid. Nanostructured samples were prepared with nanoporous anodic aluminum oxide masks from pure polyolefins and from PO/PFPE blends containing 2 wt.% PFPE. Nanostructuring had a marked effect on the contact angle between injection moldable polyolefins and water: well-arranged, high aspect ratio nanostructure was found over the entire surface.