Journal of Materials Chemistry Blog

Scientists in China have made invisible barcodes, which could prove useful in the fight against fraud and theft, out of nanowires. 1000 times narrower than a human hair, their covert system is easily encoded, and read, with an electron beam.

Lucrative black market trading in jewellery, munitions, art etc necessitates increasingly sophisticated methods to prevent crime. Barcodes are commonplace tags for both everyday and high security items. However, they’re easy to replicate and manipulate…

Interested? The full story can be read in Chemistry World.

The original article can be read below:

Phase transformation of Sn-based nanowires under electron beam irradiation
Hong Zhang, Xia Deng, Junwei Zhang, Desheng Xue, Yuanqing Huang, Feiming Bai, Beverly J. Inkson and Yong Peng
J. Mater. Chem. C, 2015, Advance Article
DOI: 10.1039/C5TC00686D

Scientists have discovered that a cheap and common sponge they use to clean surfaces and equipment in their lab has a very high capacity to absorb bisphenol A (BPA).

‘It was an accidental discovery,’ says Wei Qiu, from the University of Massachusetts, US, one of the researchers involved. ‘There was a big tank of waste BPA solution and while we were testing some other absorbent materials we accidentally dropped a sponge into the solution. We were curious and when we tested the waste solution we found a significant drop in BPA concentration and the only thing that could account for that drop was the sponge.’

Interested? The full story can be read at Chemistry World.

Domestic sponge fortuitously found to soak up bisphenol A

The original article can be read below:

Consumer-grade polyurethane foam functions as a large and selective absorption sink for bisphenol A in aqueous media
Jie Han, Wei Qiu, Saumya Tiwari, Rohit Bhargava, Wei Gao and Baoshan Xing
J. Mater. Chem. A, 2015, 3, 8870-8881
DOI: 10.1039/C5TA00868A

Researchers in China have taken inspiration from fish scales and skeleton flowers to make a transparent underwater surface that stays clean by repelling oil.

Light scattering means that many synthetic oil-repellent surfaces are opaque, limiting their use. A transparent, oil-repellent surface would have applications in biology and underwater optics, including in diving goggles and cameras. Now, Feng Chen’s research group at Xi’an Jiaotong University has developed such a material.

Interested? The full story can be read at Chemistry World.

In air (a) the surface is misty but underwater (b) it has high transparency and repels oil

The original article can be read below:

Bioinspired transparent underwater superoleophobic and anti-oil surfaces
Jiale Yong, Feng Chen, Qing Yang, Guangqing Du, Chao Shan, Hao Bian, Umar Farooq and Xun Hou
J. Mater. Chem. A, 2015, Advance Article
DOI: 10.1039/C5TA01104C

Inspired by a YouTube video, scientists in the US have confirmed that a simple bounce test can be used as a technique to indicate charge in a battery.

Alkaline AA batteries are one of the most common battery types and there are a range of approaches to assess the charge in these batteries, often entailing electronic indicators. Now, a team led by Daniel Steingart of Princeton University have correlated the coefficient of restitution (COR), a measure of bounce, with batteries at various charges and determined their charge to a similar degree of accuracy as in situ energy-dispersive x-ray diffraction (EDXRD).

Interested? Read the full story at Chemistry World.

A simple bounce test provides a considerable amount of information on the structure of a battery's anode

The original article can be read below:

The relationship between coefficient of restitution and state of charge of zinc alkaline primary LR6 batteries
Shoham Bhadra, Benjamin J. Hertzberg, Andrew G. Hsieh, Mark Croft, Joshua W. Gallaway, Barry J. Van Tassell, Mylad Chamoun, Can Erdonmez, Zhong Zhong, Tal Sholklapper and Daniel A. Steingart
J. Mater. Chem. A, 2015, Advance Article
DOI: 10.1039/C5TA01576F

Researchers in Japan have developed a white light-emitting device (WLED) that works in outdoor lighting systems but avoids disrupting plant growth.

Outdoor lighting systems can disrupt natural plant growth © Shutterstock

Lighting systems across much of the world are currently based on WLEDs, and there have been many advances to reduce energy consumption without loss of brightness. This is great news for indoor lighting but problems arise when these WLED systems are used for outdoor lighting.

Interested? Read the full story at Chemistry World.

The original article can be read below:

Plant habitat-conscious white light-emitting devices: Dy3+-emission considerably reduces involvement in photosynthesis
Tomohiko Nakajima, Harumi Hanawa and Tetsuo Tsuchiya
J. Mater. Chem. C, 2015, Advance Article
DOI: 10.1039/C4TC02558J

The UK laboratory behind the pee-powered mobile phone has gone a wee bit further and turned recycled photocopier paper into microbial fuel cells that instigate radio transmissions when fed fresh urine.

The device could find use in remote locations

Microbial fuel cells (MFCs) use bacteria to generate electricity from waste fluids. However, they are hindered by expensive and toxic components, low power output and lengthy inoculation periods, with the mobile phone-charging MFCs requiring bulky and specialist materials. In contrast, the new paper-based MFCs from Jonathan Winfield, at the Bristol BioEnergy Centre, and co-workers are much smaller, lighter and cheaper.

Interested? Read the full story at Chemistry World.

The original article can be read below:

Urine-activated origami microbial fuel cells to signal proof of life
Jonathan Winfield, Lily D. Chambers, Jonathan Rossiter, John Greenman and Ioannis Ieropoulos
J. Mater. Chem. A, 2015, Advance Article
DOI: 10.1039/C5TA00687B

Scientists in Germany have successfully preserved delicate structural details in scarab beetles by using an ionic polymer to drive carbonisation. Due to their fossil-like and stable carbon structure, the specimens are anticipated to last for thousands of years.

The beetle starts off blue but turns brown when covered with the polymer coating

Jiayin Yuan, who led the study at the Max Planck Institute of Colloids and Interfaces, explains how his team discovered the technique: ‘In the past year we began to investigate interactions between poly(ionic liquid)s [PILs] and natural matrixes like cotton. Cotton coated with PIL and carbonised was thermally stable and its natural bio-matrix was preserved. For this reason, and motivated by an intrinsic curiosity typical of us scientists, we wanted to explore and push forward this effect to its limit.’

Interested? Read the full story at Chemistry World.

The original article can be read below:

Microstructure replication of complex biostructures via poly(ionic liquid)-assisted carbonization
Martina Ambrogi, Karoline Täuber, Markus Antonietti and Jiayin Yuan
J. Mater. Chem. A, 2015, 3, 5778-5782
DOI: 10.1039/C5TA00149H

US scientists have developed an adhesive tape that can help objects match the infrared reflectance of their surroundings and disguise them from being seen by infrared cameras. The flexible coating – based on a protein found in cephalopod skin – can moderate reflectance simply by stretching and may find application in military camouflage kit.

Cephalopods – such as squid, octopuses and cuttlefish – are nature’s masters of disguise. Their skins contain iridophores, cells that reflect and manipulate incident light to spectacular effect. Their plasma membranes fold to encompass lamellar-like platelets containing reflectin. Reversible phosphorylation of reflectin changes the size and structure of the lamellae, changing the iridophore’s reflectance across the visible spectrum.

Cuttlefish and other cephalopods are some of nature’s best camouflage artists © Shutterstock

 Interested? Read the full story at Chemistry World.

The original article can be read below:

Infrared invisibility stickers inspired by cephalopods
Long Phan, David D. Ordinario, Emil Karshalev, Ward G. Walkup IV, Michael A. Shenk and Alon A. Gorodetsky
J. Mater. Chem. C, 2015, Advance Article 
DOI: 10.1039/C5TC00125K

In a creative application of rational design, scientists in China have turned to nature to help overcome one of the key challenges facing the most probable successor to the lithium ion (Li-ion) battery. Lithium–sulfur (Li–S) batteries are cheaper, more sustainable and already capable of delivering up to three times the energy density of most Li-ion cells. However, they are held back by poor stability; a problem these researchers have confronted by functionalising the electrodes with DNA.

Li–S cells typically consist of a lithium metal anode and a carbon–sulfur cathode separated by a liquid electrolyte. Lithium ions dissolve from the anode during discharge, reacting with sulfur to form lithium polysulfides (Li₂S_x) at the cathode, while the reverse occurs on charging. Some of the polysulfide intermediates are unfortunately soluble in the electrolyte and their dissolution from the cathode leads to irreversible loss of the active sulfur, adversely affecting cell performance.

Interested? Read the full story at Chemistry World.

Functionalising electrodes with DNA significantly enhances performance © Shutterstock

The original article can be read below:

High-performance lithium/sulfur batteries by decorating CMK-3/S cathodes with DNA
Qiyang Li, Chenggang Zhou, Zhuan Ji, Bo Han, Liang Feng and Jinping Wu
J. Mater. Chem. A, 2015, Advance Article
DOI: 10.1039/C4TA06083K