Category Chemistry/Nanotechnology

Interfacial Donor–Acceptor Nanofibril Composites for Selective Alkane Vapor Detection

Alkane fuel is a key ingredient in combustible material such as gasoline, airplane fuel, oil – even a homemade bomb. Yet it’s difficult to detect and there are no portable scanners available that can sniff out the odorless and colorless vapor. But University of Utah engineers have developed a new type of fiber composite for a handheld scanner that can detect small traces of alkane fuel vapor, a valuable advancement that could be an early-warning signal for leaks in an oil pipeline, an airliner, or for locating a terrorist’s explosive. It involves two nanofibers transferring electrons from one to the other.

“These are 2 materials that interact well together by having electrons transferring from one to an...

Phenanthroline ligands used in the borylation of methane. Credit: IBS

Using a new hybrid breed of computational and experimental chemistry, an international team of chemists was able to solve a puzzle that has been dubbed a ‘Holy Grail reaction’ and devise a method for catalyzing reactions with methane. As organic chemistry evolved, techniques for catalyzing hydrocarbons advanced and one by one a method was created for their manipulation. Ethane, propane, butane, pentane – all the alkanes followed a similar pattern and their reactions had predictable results. Only one alkane-methane- refused to follow suit and this confounded chemists for decades. Methane had been just too difficult to work with; its C-H bond could not be manipulated...

Depiction of photon recycling inside the crystalline structure of perovskite. Credit: Criss Hohmann

Scientists have discovered that a highly promising group of materials known as hybrid lead halide perovskites can recycle light which could lead to large gains in the efficiency of solar cells. As well as being cheap and easy to produce, perovskite solar cells have, in the space of a few years, become almost as energy-efficient as silicon – the material currently used in most household solar panels.

By showing that they can also be optimised to recycle light, the new study suggests that this could just be the beginning...

Illustration of a graphene nanoribbon with zigzag edges and the precursor molecules used in its manufacture. Electrons on the two zigzag edges display opposite directions of rotation (spin) — “spin-up” on the bottom edge (red) or “spin-down” on the top edge (blue). Credit: EMPA

Scientists have now managed to synthesise GNR with perfectly zigzagged edges using suitable carbon precursor molecules and a perfected manufacturing process. The zigzags followed a very specific geometry along the longitudinal axis of the ribbons. This is an important step, because researchers can thus give graphene ribbons different properties via the geometry of the ribbons and especially via the structure of their edges.

With molecules in a U-shape, which they allowed to grow together to form a snake-like shape, ...