InterNano Nanomanufacturing Repository
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Room temperature magnetic materials from nanostructured diblock copolymers
No full textNanostructured magnetic materials are important for many advanced applications. Consequently, new methods for their fabrication are critical. However, coupling self-assembly to the generation of magnetic materials in a simple, straight-forward manner has remained elusive. Although several approaches have been considered, most have multiple processing steps, thus diminishing their use of self-assembly to influence magnetic properties. Here we develop novel block copolymers that are preprogrammed with the necessary chemical information to microphase separate and deliver room temperature ferromagnetic properties following a simple heat treatment. The importance of the nanostructured confinement is demonstrated by comparison with the parent homopolymer, which provides only paramagnetic materials, even though it is chemically identical and has a higher loading of the magnetic precursor. In addition to the room temperature ferromagnetic properties originating from the block copolymer, the in situ generation densely functionalizes the surface of the magnetic elements, rendering them oxidatively stable
Polyethylene Glycol Grafted Polyethylene: A Versatile Platform for Nonmigratory Active Packaging Applications
No full textFederal Government Policy Principles on Nanotechnology: Balancing Regulation and Oversight with Commercialization to Realize Full Potential
No full textAs the U.S. Senate Committee on Commerce, Science and Transportation considers a reauthorization of the National Nanotechnology Initiative, the Space and Science Subcommittee convened a hearing this month to examine the potential of nanotechnology. With Senator John D. Rockefeller IV (D-WV) chairing the hearing, expert testimony was provided by a panel that included Dr. Chad Mirkin, Director, International Institute for Nanotechnology, Northwestern University, Member of the President's Council of Advisors on Science and Technology (PCAST); Dr. Charles Romine, Acting Associate Director, Laboratory Programs, and Principal Deputy, Office of the Director, National Institute of Standards and Technology; Dr. Diandra Leslie-Pelecky, Director, West Virginia Nano Initiative, Professor of Physics, West Virginia University; Dr. Thomas O'Neal, Associate Vice President for Research and Commercialization, University of Central Florida Executive Director, University of Central Florida Business Incubation Program; and Dr. George McLendon, Howard R. Hughes Provost and Professor of Chemistry, Rice University. The panel of experts provided testimony on topics such as federal initiatives to coordinate research investments, barriers to commercialization, possible environmental and health risks, and steps the federal government can take to improve the return on federal nanotechnology investments.
Also included: NIST Seeks Comments on Structure for Proposed Advanced Manufacturing Technology Consortia, National Nanotechnology Initiative nanoEHS Workshop Series Reports Now Available, and Nanomechanics: New Test Measures Key Properties of Polymer Thin Films and Membranes, and NanoBusiness Alliance Interview - Michael R. Knap
Supercapacitors Based on C-Type cytochromes Using Electrically Conductive Nanostructured Networks of Living Bacteria
No full textUsing the Fact that Wetting Is Contact Line Dependent
No full textTwo series of experiments, both involving contact line pinning, are reported that were designed using the contact line perspective of wetting and require this perspective to explain the observed results. Perspectives based on contact areas, for example, Wenzel's and Cassie's, are not useful in either of these experimental situations. In the first type of experiment described, sessile water drops were pinned on low contact angle hysteresis surfaces using 40 different shape/size lithographed hydrophilic features. Hydrophilic arcs (sections of circles), short wedges (pointed to the center of the circle), long wedges (pointed to the opposite side of the circle), and the upper outlines of the short and long wedges were prepared and studied. These features were based on circles with diameters of 4 and 6 mm and arcs of 30 degrees, 60 degrees, 90 degrees, and 120 degrees. The volume of water that could be pinned depends on the linear shape of the portion of the feature that interacts with the receding contact line and not on the feature area. In the second type of experiment, thin hydrophilic contact lines were used to support films of water (puddles and kinetically trapped thin films) on water-repellent surfaces and used to control the shape (both 2D and 3D) of these thin films and puddles. Elongated water puddles, 60 mm long and 4 mm wide, were prepared using contact line patterns with line widths of 500, 250, and 100 mu m. Curved puddles, geometric shapes, letters of the English alphabet, and puddles with variable liquid thicknesses (heights) were also prepared
Graphene-Supported Pt-Au Alloy Nanoparticles: A Highly Efficient Anode for Direct Formic Acid Fuel Cells
No full textGraphene-supported Pt and Pt-Au alloy electrocatalysts are prepared by ethylene glycol reduction method and characterized with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDX). XRD reveals the face-centered cubic structure of Pt in the materials. SEM and TEM images show the good spatial distribution of metal nanoparticles on layered graphene sheets. EDX reveals that the average composition of elements in the Pt-Au alloy catalyst is approximately 1:1. Electrocatalytic performance of the prepared materials toward formic acid oxidation (FAO) is investigated using cyclic voltammetry. FAO activity of the Pt-Au/graphene is found to be ten times higher than that of Pt/graphene. The prepared electrocatalysts are used as anode in a direct formic acid fuel cell and tested at 303 and 333 K. An increase in the performance with increasing temperature is observed. A maximum power density of 185, 70, and 53 mW/cm(2) is observed with Pt-Au/graphene, Pt/graphene, and Commercial Pt/C anodes, respectively, at 333 K. The high electrocatalytic performance of Pt-Au/graphene is attributed to the change in the electronic structure of Pt by the presence of alloying element, Au
