Materials offering huge potential using newspapers and sugar as the raw material and by means of simple chemical reactions are being synthesised at the UPV/EHU-University of the Basque Country
Erlantz Lizundia, a researcher in the UPV/EHU's department of Physical Chemistry and expert in cellulose, started the research during a period of time he spent in Canada. The research group he was in specialised in the helix-shaped organisation of a product extracted from cellulose, cellulose nanocrystals (CNCs).
Under specific conditions, the crystals can assume a helical structure, or what is the same, they can form chiral nematic structures when the crystals are organised into ordered layers, and membranes with unique properties can thus be obtained:
"The membrane displays a different colour depending on the distance existing between the layers of cellulose nanocrystals that form the helical, or chiral nematic structure. An interaction takes place between the structure and the light and, as a result, the wavelength of the light changes and materials in bright colours are obtained," explained Lizundia. This capacity to change colour displayed by the structure "could prove very useful in enabling these membranes to be used as sensors; for example, when they are put into a humid environment, the structure will swell and the distance between the layers will increase and the colour will change," he added.
This effect is known as structural coloration and is very common in nature. The colour of a whole host of animals (snakes, chameleons) and plants is the direct consequence of their supramolecular structure, and contrary to what one may think, is not linked to the presence of pigments. Suitable as metal sensors and for bioimaging purposes
Inserting carbon dots into the chiral nematic structure of the cellulose nanocrystals makes this material particularly suited as a detector for the presence of iron so, as Lizundia explains, "it is very useful for detecting environmental pollution or the presence of metals in the body. I, specifically, studied the material's response to zinc and iron, as they are both present in large quantities in environmental and biological matters.
I was able to see that the interaction of the metal ions with the carbon nanoparticles influences the degree of fluorescence emitted by the nanoparticles. The fluorescence diminishes in the presence of iron, whereas it increases in the presence of zinc".
Another possible application of this material could be in bioimaging. In the research conducted, Lizundia only managed to get as far as testing that it does in fact offer this possibility. "I will shortly be embarking on research to go further into this subject and use these nanoparticles to create bioimages". Bioimaging consists of creating images using non-invasive methods in biological processes, such as cell processes, as well as measuring the interaction between molecules in real time in the location where these interactions are taking place.
The UPV/EHU researcher Erlantz Lizundia conducted his research work in collaboration with the University of British Columbia (UBC) in Canada, and with the FPInnovations organisation, also Canadian. At that time, Lizundia was a researcher in the department of Physical Chemistry on the UPV/EHU's Leioa campus. Right now, however, he is assistant lecturer in the Department of Graphic Expression and Engineering Projects in the Faculty of Engineering in Bilbao.
E. Lizundia, T.D. Nguyen, J. L. Vilas, W. Y. Hamad, M. J. MacLachlan.. Chiroptical luminescent nanostructured cellulose films. Materials Chemistry Frontiers. 2016. DOI: 10.1039/C6QM00225K.
Wanting to go a step beyond what he had learned in Canada, Lizundia considered incorporating other functional nanoparticles into this chiral nematic structure, particles whose properties change in the presence of external stimuli. He chose some carbon nanodots, firstly because they are fluorescent, in other words, they emit colour when excited by ultraviolet light, and secondly, because he was able to obtain them by using sugar as the raw material. "I obtained these nanoparticles by subjecting glucose to hydrothermal treatment using water and heat only and by means of a fast, cheap process," the researcher pointed out.
The final material displayed the characteristics Lizundia had been seeking. Firstly, "it is an environmentally friendly material as it is non-toxic and its raw materials are of a renewable nature, and the synthesis process is fast, simple and scalable. Secondly, the fact that the material is fluorescent gives it interesting properties enabling it to be used as a sensor," specified Lizundia.
Matxalen Sotillo | EurekAlert!
Watching atoms move in hybrid perovskite crystals reveals clues to improving solar cells
22.11.2017 | University of California - San Diego
Fine felted nanotubes: CAU research team develops new composite material made of carbon nanotubes
22.11.2017 | Christian-Albrechts-Universität zu Kiel
Heat from the friction of rocks caused by tidal forces could be the “engine” for the hydrothermal activity on Saturn's moon Enceladus. This presupposes that...
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
23.11.2017 | Information Technology
23.11.2017 | Physics and Astronomy
23.11.2017 | Life Sciences