2-propanol (HFIP), aniline, and 2,3,4,5,6-pentafluoroaniline were purchased from Sigma-Aldrich Co. (St. Louis, MO). Fabrication of superhydrophobic peptide film: Amorphous thin peptide film was prepared by drying a drop of diphenylalanine solution in HFIP under an anhydrous condition in a glove box (model: MOGB 1S, Moisture Oxygen Technology Co., Korea), and then treated with pentafluoroaniline vapor (or aniline vapor for the control experiment) at 100 ºC for 12 h. A self-cleaning

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... ic surface was prepared by treating as-synthesized superhydrophobic peptide nanowire film by rapidly cooling the growth chamber temperature from 100 ºC to 50 ºC to induce a slight wetting for the rearrangement of peptide nanowires into hierarchical nano/microstructures. The thickness of amorphous peptide thin film was controlled by varying the concentration of diphenylalanine in HFIP from 5 to 100 mg ml -1 . To investigate the effect of aging temperature on the superhydrophobic characteristics of peptide thin films, we prepared the films at a constant temperature of 27, 50, 75, 100, 175, 250, and 300 ºC. Characterization: The morphology of peptide thin films before and after the solvent-vapor treatment was analyzed by an S-4800 field emission SEM (Hitachi Ltd., Japan). The static water contact angle of each surface was measured with a Phoenix 300 contact-angle meter (Surface Electro Optics Co., Ltd., Korea) at five different locations on each film using 6 mg of water droplet. The accuracy of contact