Synthesis of Perpendicular Nanorod Arrays with Hierarchical Architecture and Water Slipping Superhydrophobic Properties

Department of Chemistry, BK21 School of Chemical Materials Science and SKKU Advanced Institute of Nanotechnology, Sungkyunkwan University, Suwon, South Korea.
Langmuir (Impact Factor: 4.46). 05/2008; 24(8):4168-73. DOI: 10.1021/la7026972
Source: PubMed


The utilization of vertically aligned smooth gold nanorod arrays with and without nanoporous tip architectures as superhydrophobic surfaces is described. Nanoporous architecture was produced on the tips of nanorods by selectively dissolving less noble components from the alloy nanorods. The resulting nanoscopic dual-size roughness features enhanced the surface dewettability after surface modification with low-surface-energy materials such as long-chain normal alkanethiols and fluorinated organic compounds. The surface cleaning properties were also tested with a rolling water droplet.

Full-text preview

Available from:
  • [Show abstract] [Hide abstract]
    ABSTRACT: Here we present a simple process to synthesize artificial water-repellent leaf structures through the introduction of hierarchical nanostructures to the surface using anodized aluminum oxide templates. Unlike cylindrical nanopores fabricated by conventional anodization, biomimetic hierarchical structures were manufactured by multi-step anodization of nanoscopically pre-patterned Al. From the hierarchical anodized aluminum oxide templates, the perfluoropolyether nanostructures were simply replicated and repeatedly obtained by reusing the anodized aluminum oxide templates without anti-adhesion coating. Upon the investigation of the wettability of perfluoropolyether hierarchical surfaces, it was found that the surface became more hydrophobic (∼152°) with the increase of the structural complexity, and are comparable to water-repellent leaf surfaces found in nature.
    No preview · Article · Jul 2012 · Macromolecular Research
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: We have successfully fabricated a layer-by-layer (LBL)-assembled functional bio-architecture on gold nanorod substrates with an increased number of immobilized biomolecules. The vertical array of gold nanorods was fabricated through an electrochemical process, using porous aluminum oxide as a template and the dispersed film of gold nanorods was prepared by using the Langmuir-Blodgett technique. Horse radish peroxidase was immobilized on the vertical array and on the dispersed film of gold nanorods through LBL assembly by using the specific interaction between avidin-biotin molecules. The levels of catalytic activity of the LBL-assembled bio-architectures fabricated on both the vertical array and the dispersed film of gold nanorods were, respectively, ∼2.8 and ∼1.5 times better than that of the fiat gold surface due to an increase in surface area and ease of substrate accessibility. Scanning electron microscopy (SEM) and fluorescence images clearly show a regular, successively well-controlled LBL-assembled bio-architecture with a bilayer structure of proteins on gold nanorods. This controlled fabrication of biologically active enzymes on gold nanorod structures via LBL assembly demonstrates a technique for the development of bio-functional molecular devices with enhanced sensitivities and fast response time.
    Preview · Article · Jul 2008 · Journal- Korean Physical Society
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: A new strategy was developed to prepare raspberry-like particles by introducing poly(acrylic acid) (PAA)-functionalized polystyrene (PS) particles into hydrolysis reaction of tetraethoxysilane (TEOS). The monodisperse PAA-functionalized PS particles were used as cores and nanosized silica particles were then assembled on the surface of PS particles to construct raspberry-like particles during the hydrolysis process. With the increase of PAA content from 11% to 20% (wt) at the surface of latexes, the diameter of the silica particles assembled at the surface of cores decreased from 124 nm to 36 nm. The structure, morphology and constitution of the PAA-functionalized PS particles and the raspberry-like particles were characterized by Fourier transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). In addition, the particulate films were constructed by assembling these raspberry-like particles on glass substrates. After surface modification with dodecyltrichlorosilane, superhydrophobic surfaces can be obtained and the contact angle of water on the dual-sized structured surface can be adjusted by the scale ratio of the micro/nano surface structure of raspberry-like particles.
    Full-text · Article · Jan 2009 · Journal of Materials Chemistry
Show more