Category Chemistry/Nanotechnology

Electrical characteristics of graphene-azobenzene hybrid materials.(a) Scheme of the two-terminal device. (b) Reversible current modulation as a response to the device irradiation with different wavelengths (cycles of UV and visible light). (c) Scheme of the hybrid graphene–azobenzene structure when exposed to cycles of UV and visible light. Credit: Image courtesy of Graphene Flagship

Imagine a world where you can tailor the properties of graphene to have the outcome you desire. By combining its unique properties with the precision of molecular chemistry, scientists from Graphene Flagship have taken the first steps towards doing just that...

Three-dimensional network structure of the highly porous and flexible material DUT-49 (DUT= Dresden University of Technology) which displays the NGA-effect. Credit: Image courtesy of Technische Universitaet Dresden

Prof. Dr. Stefan Kaskel et al have found a new phenomenon in the field of gas-solid interactions: the so-called Negative Gas Adsorption (NGA). Adsorption refers to the process by which molecules of a gas collect on the surface of a solid. Metal-organic frameworks are highly porous materials which are widely used for adsorptive applications such as in the reduction of pollutant emissions.

The scientists from Dresden, Berlin and France have now succeeded in demonstrating that these materials can dynamically change their structures...

In order to allow rain to produce electricity as well, the research team coated a solar cell with a whisper-thin film of graphene. Credit: Copyright Angewandte Chemie International Edition; courtesy of ResearchSEA

Many advances have made solar cells quite efficient and affordable but a disadvantage is that solar cells produce no power when it’s raining. This may change, however. Chinese researchers have now introduced a new approach for making an all-weather solar cell that is triggered by both sunlight and raindrops. They developed a highly efficient dye-sensitized solar cell. In order to allow rain to produce electricity as well, they coated this cell with a whisper-thin film of graphene.

Graphene can readily be prepared by the oxidation, exfoliation, and subsequent reduction of graphite...

Shear jamming image. Credit: Image courtesy of University of Southampton

Liquid-like materials with particles in, known as dense suspensions, are found in the food industry (eg molten chocolate) and clay deposits on the bottom of oceans or rivers. Understanding the ‘jamming transition’ – when such a system behaves like a solid (if you want to build something on it) or when it flows (important if you want to process it) – could help in the design of new materials that actively use this transition from fluid-like to solid-like behaviour.

Ivo Peters, Lecturer in Aerodynamics and Flight Mechanics Research Group at the Uni of Southampton...