Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Airy but Thirsty

26.02.2013
Ultralight, flexible, fire-resistant carbon nanotube aerogels from bacterial cellulose

They can absorb vast amounts of oil or organic compounds, yet they are nearly as light as air: highly porous solids made of a three-dimensional network of carbon nanotubes.

In the journal Angewandte Chemie, Chinese scientists have now introduced a simple technique for the production of these ultralight, flexible, fire-resistant aerogels. Their method begins with bacterial cellulose as an inexpensive starting material. Their fibrous lightweights can "suck" organic contaminants from polluted water and could possibly be used as pressure sensors.

Their unique properties—low density, highy porosity, high specific surface, and high electrical conductivity—make carbon aerogels promising new materials. They could be used as catalyst supports, electrodes for supercapacitors, adsorbents, and gas sensors, as well as for synthetic muscles. However, there is still no simple, industrially and environmentally friendly method for the production of these attractive lightweights.

A team led by Shu-Hong Yu at the Hefei National Laboratory for Physical Sciences at Micrscale (HFNL), Univeristy of Science and Technology of China is pursuing their production from biomass. They selected bacterial cellulose, a commonly used, inexepensive, nontoxic form of biomass consisting of a tangled network of cellulose nanofibers. This material can easily be produced on an industrial scale through microbial fermentation.

The researchers trimmed off small pieces of the tangled cellulose nanofibers. These were freeze-dried and then pyrolyzed at 1300 °C under argon. This converts the cellulose into graphitic carbon. The density decreases but the network structure remains intact. The result is a black, ultralight, mechanically stable aerogel. Because it is porous and highly hydrophobic, it can adsorb organic solvents and oils—up to 106 to 312 times its own weight.

It draws oil out of an oil/water mixture with high efficiency and selectivity, leaving behind pure water. This makes the new aerogel an ideal candidate for cleaning up oil spills or sucking up nonpolar industrial pollutants. The absorbed substances can easily be removed from the gel through distillation or combustion, allowing the gel to be used again.

The extraordinary heat- and fire-resistence of this material are particularaly noteworthy: repeated treatment with the flame of a torch caused no changes in its form or inner three-dimensional pore structure.

The high electrical conductivity of the aerogel also suggests the possibility of electronic applications. The material has high mechanical flexibility. It can be compressed to about 10 % of its original volume and will subsequently expand back to nearly its original shape. Its conductivity decreases in a nearly linear fashion with increasing compression, which could allow the aerogel to be used as a pressure sensor.

About the Author
Professor Shu-Hong Yu is a Full professor at the Hefei National Laboratory for Physical Sciences at Micrscale (HFNL), University of Science and Technology (USTC), China. He is the Head of the Division of Nanomaterials & Chemistry, and also acting as the Deputy Dean of the School of Chemistry & Materials. He is the recipient of the Roy-Somiya Medal of the International Solvothermal and Hydrothermal Association (ISHA) (2010), Chem Soc Rev Emerging Investigator Award (2010) by the Royal Society of Chemistry (UK). His main specialty includes controlled synthesis of new functional nanoparticles, and macroscopic-scale assembly of nanoscale building blocks, and their applications in energy storage, energy conversion, environment protection and other sustainable application systems.
Author: Shu-Hong Yu, University of Science and Technology of China, Hefei (P.R. China), http://staff.ustc.edu.cn/~yulab/
Title: Ultralight, Flexible, and Fire-Resistant Carbon Nanofiber Aerogels from Bacterial Cellulose

Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201209676

Shu-Hong Yu | Angewandte Chemie
Further information:
http://pressroom.angewandte.org

More articles from Life Sciences:

nachricht New Model of T Cell Activation
27.05.2016 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht Fungi – a promising source of chemical diversity
27.05.2016 | Leibniz-Institut für Naturstoff-Forschung und Infektionsbiologie - Hans-Knöll-Institut (HKI)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Worldwide Success of Tyrolean Wastewater Treatment Technology

A biological and energy-efficient process, developed and patented by the University of Innsbruck, converts nitrogen compounds in wastewater treatment facilities into harmless atmospheric nitrogen gas. This innovative technology is now being refined and marketed jointly with the United States’ DC Water and Sewer Authority (DC Water). The largest DEMON®-system in a wastewater treatment plant is currently being built in Washington, DC.

The DEMON®-system was developed and patented by the University of Innsbruck 11 years ago. Today this successful technology has been implemented in about 70...

Im Focus: Computational high-throughput screening finds hard magnets containing less rare earth elements

Permanent magnets are very important for technologies of the future like electromobility and renewable energy, and rare earth elements (REE) are necessary for their manufacture. The Fraunhofer Institute for Mechanics of Materials IWM in Freiburg, Germany, has now succeeded in identifying promising approaches and materials for new permanent magnets through use of an in-house simulation process based on high-throughput screening (HTS). The team was able to improve magnetic properties this way and at the same time replaced REE with elements that are less expensive and readily available. The results were published in the online technical journal “Scientific Reports”.

The starting point for IWM researchers Wolfgang Körner, Georg Krugel, and Christian Elsässer was a neodymium-iron-nitrogen compound based on a type of...

Im Focus: Atomic precision: technologies for the next-but-one generation of microchips

In the Beyond EUV project, the Fraunhofer Institutes for Laser Technology ILT in Aachen and for Applied Optics and Precision Engineering IOF in Jena are developing key technologies for the manufacture of a new generation of microchips using EUV radiation at a wavelength of 6.7 nm. The resulting structures are barely thicker than single atoms, and they make it possible to produce extremely integrated circuits for such items as wearables or mind-controlled prosthetic limbs.

In 1965 Gordon Moore formulated the law that came to be named after him, which states that the complexity of integrated circuits doubles every one to two...

Im Focus: Researchers demonstrate size quantization of Dirac fermions in graphene

Characterization of high-quality material reveals important details relevant to next generation nanoelectronic devices

Quantum mechanics is the field of physics governing the behavior of things on atomic scales, where things work very differently from our everyday world.

Im Focus: Graphene: A quantum of current

When current comes in discrete packages: Viennese scientists unravel the quantum properties of the carbon material graphene

In 2010 the Nobel Prize in physics was awarded for the discovery of the exceptional material graphene, which consists of a single layer of carbon atoms...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Networking 4.0: International Laser Technology Congress AKL’16 Shows New Ways of Cooperations

24.05.2016 | Event News

Challenges of rural labor markets

20.05.2016 | Event News

International expert meeting “Health Business Connect” in France

19.05.2016 | Event News

 
Latest News

3-D model reveals how invisible waves move materials within aquatic ecosystems

30.05.2016 | Materials Sciences

Spin glass physics with trapped ions

30.05.2016 | Materials Sciences

Optatec 2016: Robust glass optical elements for LED lighting

30.05.2016 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>