Nonfunctionalized polydimethyl siloxane superhydrophobic surfaces based on hydrophobic-hydrophilic interactions.

摘要: Superhydrophobic surfaces based on polydimethyl siloxane (PDMS) were fabricated using a 50:50 PDMS-poly(ethylene glycol) (PEG) blend. PDMS was mixed with PEG, and incomplete phase separation yielded hierarchic structure. The phase-separated mixture annealed at temperature close to the crystallization of PEG. PEG crystals formed isothermally PDMS/PEG interface, leading an engineered surface spherulites. resulting roughness studied by scanning electron microscopy (SEM) atomic force (AFM). spherulites, few micrometers in diameter observed from SEM images, found have undulated (rippled) nanometer-sized features. combination micrometer- features created fractal increased water contact angle (WCA) more than 60°, superhydrophobic WCA >160°. active layer for superhydrophobicity approximately 100 μm thick, illustrating that material had bulk compared conventional fluorocarbon or fluorinated coated rough surfaces. Theoretical analysis indicates constructed has dimension 2.5, which corresponds Apollonian sphere packing.