Category Chemistry/Nanotechnology

Nanocrystalline LEDs: Red, green, yellow, blue…

Foto: Foto Ruhrgebiet / fotolia.com

Confining metal-halide perovskites in nanoporous thin films. Science Advances, 2017; 3 (8): e1700738 DOI: 10.1126/sciadv.1700738 Foto: Foto Ruhrgebiet / fotolia.com

The color of the light emitted by an LED can be tuned by altering the size of their semiconductor crystals. Ludwig-Maximilians-Universitaet (LMU) in Munich researchers have now found a clever and economical way of doing just that, which lends itself to industrial-scale production. Unlike incandescent lightbulbs, light-emitting diodes produce light of a defined color within the spectral range from the infrared to the ultraviolet. The exact wavelength of the emission is determined by the chemical composition of the semiconductor, the crucial component...

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Software lets Designers Exploit the Extremely High Resolution of 3D Printers

MIT researchers have developed a new design system that catalogues the physical properties of a huge number of tiny cube clusters. These clusters can then serve as building blocks for larger printable objects. Credit: Computational Fabrication Group at MIT

MIT researchers have developed a new design system that catalogues the physical properties of a huge number of tiny cube clusters. These clusters can then serve as building blocks for larger printable objects. Credit: Computational Fabrication Group at MIT

Designing the microstructure of printed objects. Today’s 3D printers have a resolution of 600 dots per inch, ie they could pack a billion tiny cubes of different materials into a volume that measures just 1.67 cubic inches. Such precise control of printed objects’ microstructure gives designers commensurate control of the objects’ physical properties – eg. density or strength, or the way they deform when subjected to stresses...

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Lightweight Catalyst for Artificial Photosynthesis

Lightweight Catalyst for Artificial Photosynthesis - Carbonitride aerogels mediate the photocatalytic conversion of water

Carbon Nitride Aerogels for the Photoredox Conversion of Water. Angewandte Chemie International Edition, 2017; DOI: 10.1002/anie.201705926 © Wiley-VCH

Carbonitride aerogels mediate the photocatalytic conversion of water. Nanochemistry meets macrostructures: Chinese scientists report the synthesis of a macroscopic aerogel from carbonitride nanomaterials which is an excellent catalyst for the water-splitting reaction under visible-light irradiation. The study published in the journal Angewandte Chemie adds new opportunities to the material properties of melamine-derived carbonitrides.

Melamine can be polymerized with formaldehyde to give a highly durable and light resin, but it can also condensed to form nanostructures of carbonitride materials...

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Heat-Conducting Plastic could lead to Lighter Electronics, Cars

A sample of heat - conducting polymer is tested for thickness in U-M’s Lurie Nanofabrication Facility. Image credit: Joseph Xu, Michigan Engineering

A sample of heat – conducting polymer is tested for thickness in U-M’s Lurie Nanofabrication Facility. Image credit: Joseph Xu, Michigan Engineering

Advanced plastics could usher in lighter, cheaper, more energy-efficient product components, including those used in vehicles, LEDs and computers – if only they were better at dissipating heat. A new technique that can change plastic’s molecular structure to help it cast off heat is a promising step in that direction. Developed by a team of University of Michigan researchers in materials science and mechanical engineering and detailed in a new study published in Science Advances, the process is inexpensive and scalable.

The concept can likely be adapted to a variety of other plastics...

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