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Article
UVO-tunable superhydrophobic to superhydrophilic wetting transition on biomimetic nanostructured surfaces
Polymer Engineering Faculty Research
  • Alamgir Karim
Document Type
Article
Publication Date
10-1-2007
Abstract

A novel strategy for a tunable sigmoidal wetting transition from superhydrophobicity to superhydrophilicity on a continuous nanostructured hybrid film via gradient UV-ozone (UVO) exposure is presented. Along a single wetting gradient surface (40 mm), we could visualize the superhydrophobic (thetaH2O > 165 degrees and low contact angle hysteresis) transition (165 degrees > thetaH2O > 10 degrees ) and superhydrophilic (thetaH2O < 10 degrees within 1 s) regions simply through the optical images of water droplets on the surface. The film is prepared through layer-by-layer assembly of negatively charged silica nanoparticles (11 nm) and positively charged poly(allylamine hydrochloride) with an initial deposition in a fractal manner. The extraordinary wetting transition on chemically modified nanoparticle layered surfaces with submicrometer- to micrometer-scale pores represents a competition between the chemical wettability and hierarchical roughness of surfaces as often occurs in nature (e.g., lotus leaves, insect wings, etc).

Citation Information
Alamgir Karim. "UVO-tunable superhydrophobic to superhydrophilic wetting transition on biomimetic nanostructured surfaces" Vol. 5 (2007) p. 23
Available at: http://works.bepress.com/alamgit_karim/8/