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    Category Chemistry/Nanotechnology

    Fluorescence Dyes from the Pressure Cooker

    January 30, 2017, Categories  Physics, Chemistry/Nanotechnology

    Fabian Zechmeister (left) and Maximilian Raab (right) demonstrate the fluorescence of a perylene bisimide solution. Credit: Image courtesy of Vienna University of Technology, TU Vienna

    Fabian Zechmeister (left) and Maximilian Raab (right) demonstrate the fluorescence of a perylene bisimide solution. Credit: Image courtesy of Vienna University of Technology, TU Vienna

    Perylene bisimides are a heavily investigated and sought after class of organic pigments, since they show interesting dye properties. While these compounds are red pigments in the solid state, when dissolved, they generate bright yellowish-green solutions under UV irradiation. Aside their optical appeal; organic molecules that appear colored in daylight often also show intriguing electronic properties. Thus, organic dyes are promising lightweight materials for application as e.g. organic semiconductors, but also in for instance LCD displays or solar cells.

    The laboratory of Dr. Miriam M...

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    Absorbing Electromagnetic Energy while Avoiding the Heat

    January 29, 2017, Categories  Physics, Technology/Electronics, Chemistry/Nanotechnology

    1. A closer look at one of the cylinders comprising a new non-metal metamaterial. The arrows depict how different aspects of an electromagnetic field interact with the cylinder. 2. Each cylinder of this new non-metal metamaterial is made of boron-doped silicon and precisely tailored to absorb electromagnetic waves.

    1. A closer look at one of the cylinders comprising a new non-metal metamaterial. The arrows depict how different aspects of an electromagnetic field interact with the cylinder.
    2. Each cylinder of this new non-metal metamaterial is made of boron-doped silicon and precisely tailored to absorb electromagnetic waves.

    Electrical engineers at Duke University have created the world’s first electromagnetic metamaterial made without any metal. The device’s ability to absorb electromagnetic energy without heating up has direct applications in imaging, sensing and lighting. Metamaterials are synthetic materials composed of many individual, engineered features that together produce properties not found in nature...

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    Taking Materials into the 3rd Dimension

    January 26, 2017, Categories  Technology/Electronics, Chemistry/Nanotechnology

    Highly ordered sodium silicate particles (bottom right) with a regular array of spherical pores (bottom left) form on silicon surface. The one-step synthesis is directed by the atomic ordering of the substrate, which induces the formation of a soft template for sodium silicate growth. Sodium silicate, in turn, modifies the structure of the soft template during growth, encapsulating it within its structure (top). Credit: Image courtesy of Pacific Northwest National Laboratory

    Highly ordered sodium silicate particles (bottom right) with a regular array of spherical pores (bottom left) form on silicon surface. The one-step synthesis is directed by the atomic ordering of the substrate, which induces the formation of a soft template for sodium silicate growth. Sodium silicate, in turn, modifies the structure of the soft template during growth, encapsulating it within its structure (top). Credit: Image courtesy of Pacific Northwest National Laboratory

    To create more efficient catalysts, sensing and separation membrane, and energy storage devices, scientists often start with particles containing tiny pore channels. Defects between the particles can hamper performance...

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    New Metamaterial can Switch from Hard to Soft – and back again

    January 24, 2017, Categories  Physics, Technology/Electronics, Chemistry/Nanotechnology

    Topological transitions of a deformed kagome lattice by uniform soft twisting.

    Topological transitions of a deformed kagome lattice by uniform soft twisting. Two types of triangles (red and blue) are connected by free hinges at their corners, forming a deformed kagome lattice with primitive vectors a1, a2. The angle θ between the triangles defines the twisting coordinate. The blue curve shows (defined in equation (1)) as a function of θ. The 3 white dots on the θ axis represent three critical angles (, and ) where sides of the triangles form straight lines (yellow stripes on the lattices) and topological polarization RT (shown as black arrows above the axes) changes.

    University of Michigan researchers have developed a new way to design a “metamaterial” that allows the material to switch between being hard and soft without damaging or altering the material itself...

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