Author Archive

Polymerisation reveals hidden fingerprints

Fingerprints leave their mark on surfaces that remain even if they are washed off allowing them to be detected using disulphur dinitride, claim UK scientists. 

Fingerprint analysis of crime scenes has become a powerful weapon in the forensic scientist’s arsenal. The ridges present on the tips of the fingers are unique to a person. By comparison of impressions left in materials – typically flat, regular surfaces, such as glass – to a sample taken from a suspect it is possible to identify the owner of the fingerprints. 

It could be possible to identify fingerprints that have been washed from surfaces

It could be possible to identify fingerprints that have been washed from surfaces

But there are occasions where fingerprints are not easily viewable or are fragmented. Here, latent fingerprinting – where obscured fingerprints are enhanced – can be used to identify an individual. In 2008, Paul Kelly and co-workers at Loughborough University noticed that the strained four-membered ring system S2N2 quickly polymerises to (SN)x in the presence of fingerprints. Detecting this polymer produces a visual image of the fingerprint. 

To view the full Highlights in Chemical Technology article, please click here: Polymerisation reveals hidden fingerprints

Link to journal article

Polymerisation of S2N2 to (SN)x as a tool for the rapid imaging of fingerprints removed from metal surfaces
Stephen M. Bleay, Paul F. Kelly and Roberto S. P. King, J. Mater. Chem., 2010
DOI:
10.1039/c0jm02724c

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Colour changing fabrics without weaving

As interest grows in clothes that do more than just keep you warm and preserve your modesty, Canadian scientists are developing non-woven textiles that exhibit a reversible colour change due to resistive heating. 

Traditional fabrics can be improved by giving them another function useful for fashion medical or military applications, explains Alexis Laforgue at the National Research Council Canada Industrial Materials Institute, Boucherville. 

Applying a current causes the material to change colour

Applying a current causes the material to change colour

Substances that change colour when an external stimulus is applied, such as heat) or electricity (know as (thermochromism or electrochromism respectively), can be added to fabrics to give them extra functionality. Laforgue’s new non-woven material is simpler than many of its thermochromic and electrochromic counterparts because the fibres don’t need to be woven through a fabric and the system doesn’t need an electrolyte layer. 

To view the full Highlights in Chemical Technology article, please click here: Colour changing fabrics without weaving

Link to journal article

Electrically controlled colour-changing textiles using the resistive heating properties of PEDOT nanofibers
Alexis Laforgue, J. Mater. Chem., 2010, 20, 8233
DOI:
10.1039/c0jm02307h

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Mimicking nature’s solar cells

US scientists have take inspiration from plants to create a water-based solar cells to convert light into electricity.

Plants efficiently use light to initiate reactions that produce energy in a process known as photosynthesis. Now Orlin Velev and colleagues at North Carolina State University, have created a hydrogel device to mimic this process to create electricity.

Flexible photovoltaic device uses water-based gel to generate electricity from sunlight

Flexible photovoltaic device uses water-based gel to generate electricity from sunlight

The device uses a 98 per cent water hydrogel doped with two photoactive dyes (9,10-dimethoxy-2-anthracenesulfonic acid and ruthenium trisbipyridine).The gel is layered between a copper foil electrode coated with carbon black and graphite and an indium tin oxide-coated plastic substrate serving as the other electrode. The dyes absorb light exciting the electrons into a higher energy state. Transport of the dyes through the hydrogel allows electrons and electron holes to be transferred to the two electrodes completing the circuit and generating a current.

To view the full Highlights in Chemical Science article, please click here: Mimicking nature’s solar cells

Link to journal article

Aqueous soft matter based photovoltaic devices
Hyung-Jun Koo, Suk Tai Chang, Joseph M. Slocik, Rajesh R. Naik and Orlin D. Velev, J. Mater. Chem., 2011
DOI:
10.1039/c0jm01820a

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Top Ten most-read Journal of Materials Chemistry articles

Read the most-read Journal of Materials Chemistry articles of August 2010, listed below:

Soo-Kang Kim, Bing Yang, Yuguang Ma, Ji-Hoon Lee and Jong-Wook Park, J. Mater. Chem., 2008, 18, 3376-3384
DOI: 10.1039/B805062G
 
Harald Hoppe and Niyazi Serdar Sariciftci, J. Mater. Chem., 2006, 16, 45-61
DOI: 10.1039/B510618B
 
John C. Hulteen and Charles R. Martin, J. Mater. Chem., 1997, 7, 1075-1087
DOI: 10.1039/A700027H
 
Soo-Kang Kim, Young-Il Park, In-Nam Kang and Jong-Wook Park, J. Mater. Chem., 2007, 17, 4670-4678
DOI: 10.1039/B706606F
 
Clément Sanchez, Beatriz Julián, Philippe Belleville and Michael Popall, J. Mater. Chem., 2005, 15, 3559-3592
DOI: 10.1039/B509097K
 
Suijun Liu, Feng He, Huan Wang, Hai Xu, Chunyu Wang, Feng Li and Yuguang Ma, J. Mater. Chem., 2008, 18, 4802-4807
DOI: 10.1039/B807266C
 
Sasha Stankovich, Richard D. Piner, Xinqi Chen, Nianqiang Wu, SonBinh T. Nguyen and Rodney S. Ruoff, J. Mater. Chem., 2006, 16, 155-158
DOI: 10.1039/B512799H
 
Li Li Zhang, Rui Zhou and X. S. Zhao, J. Mater. Chem., 2010, 20, 5983-5992
DOI: 10.1039/C000417K
 
Stéphane Mornet, Sébastien Vasseur, Fabien Grasset and Etienne Duguet, J. Mater. Chem., 2004, 14, 2161-2175
DOI: 10.1039/B402025A
 
Wei-De Zhang, Bin Xu and Liao-Chuan Jiang, J. Mater. Chem., 2010, 20, 6383-6391
DOI: 10.1039/B926341A
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