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Alsheheri S.,Nanoscale Science and Engineering Center | Saboktakin M.,University of Denver | Matin M.,University of Denver
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2015

Hybrid plasmonic nanoprisms in the form of gold (Au)-dielectric-silver (Ag) sandwich structures have been designed and simulated using Finite-difference time-domain (FDTD) simulation technique. Simulations results show two dipole resonant peaks for the hybrid sandwich structure. Also, a strong wavelength dependence of the plasmonic resonance peaks on the edge length and the thickness of gold and silver layers. The increase in edge length and thicknesses were found red shift to the plasmonic peak of the nanostructures. Furthermore, the resonant wavelengths and relative strength of the two dipole plasmonic peaks are demonstrated to be tunable. © 2015 SPIE.

He Y.,Nanoscale Science and Engineering Center | Fan J.,University of Georgia | Zhao Y.,Nanoscale Science and Engineering Center
Crystal Growth and Design | Year: 2010

A well-aligned composition-graded CuSi nanorod array structure has been fabricated by a simple oblique angle codeposition technique in a physical vapor deposition system. The Cu and Si graded composition distribution in the nanorods was confirmed by their elemental mapping and depth profiles. The crystal structure evolution with the nanorod length was revealed by both electron and X-ray diffractions. The size evolution of the CuSi nanorods followed a power law, which results from the combination effects of geometric shadowing and limited surface atomic diffusion. Such a graded composition distribution could relax the stress between the nanorods and the substrate, and is promising for applications where improved nanorod-substrate adhesion is required. © 2010 American Chemical Society.

Yatvin J.,Nanoscale Science and Engineering Center | Sherman S.A.,U.S. Army | Filocamo S.F.,U.S. Army | Locklin J.,Nanoscale Science and Engineering Center
Polymer Chemistry | Year: 2015

Generating innovative methods to functionalize fibers and interfaces are important strategies for developing coatings that impart new or improved properties to a given material. In this work, we present a method for functionalizing highly inert poly(p-phenylene terephthalamide) (Kevlar®) fibers via thermal generation of an electrophilic nitrene, while preserving the mechanical properties of the aramid. Because of the high affinity of the sulfonyl nitrene singlet state for aromatic rings, the use of a sulfonyl azide-based copolymer allows the covalent grafting of a wide variety of common commercial polymers to Kevlar. Also, by using reactive ester copolymers, an avenue for the attachment of more exotic or delicate functionalities like small molecules, dyes, and biomolecules through postpolymerization modification is described. © 2015 The Royal Society of Chemistry.

Yao K.,Nanoscale Science and Engineering Center | Manjare M.,Nanoscale Science and Engineering Center | Barrett C.A.,University of Georgia | Yang B.,University of Texas at Arlington | And 2 more authors.
Journal of Physical Chemistry Letters | Year: 2012

Layered heterostructures containing graphene oxide (GO) nanosheets and 20-35 nm bimetal coatings can detach easily from a Si substrate upon sonication-spontaneously forming freestanding, micrometer-sized scrolls with GO on the outside-due to a combination of material stresses and weak bonding between GO layers. Simple procedures can tune the scroll diameters by varying the thicknesses of the metal films, and these results are confirmed by both experiment and modeling. The selection of materials determines the stresses that control the rolling behavior, as well as the functionality of the structures. In the GO/Ti/Pt system, the Pt is located within the interior of the scrolls, which can become self-propelled microjet engines through O 2 bubbling when suspended in aqueous H 2O 2. © 2012 American Chemical Society.

Yatvin J.,Nanoscale Science and Engineering Center | Gao J.,Nanoscale Science and Engineering Center | Locklin J.,Nanoscale Science and Engineering Center
Chemical Communications | Year: 2014

Developing antimicrobial coatings to eliminate biotic contamination is a critical need for all surfaces, including medical, industrial, and domestic materials. The wide variety of materials used in these fields, from natural polymers to metals, require coatings that not only are antimicrobial, but also contain different surface chemistries for covalent immobilization. Alkyl "-onium" salts are potent biocides that have defied bacterial resistance mechanisms when confined to an interface. In this feature article, we highlight the various methods used to covalently immobilize bactericidal polymers to different surfaces and further examine the mechanistic aspects of biocidal action with these surface bound poly"-onium" salts. This journal is © the Partner Organisations 2014.

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