Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Iron Oxide as an Ultralightweight

26.02.2014

Iron oxide frameworks with hierarchical pore structure from pyrolysis of Prussian blue nanocrystals

Adsorption, catalysis, or substrates for tissue growth: porous materials have many potential applications. In the journal Angewandte Chemie, a team of Chinese and Australian researchers has now introduced a method for the synthesis of ultralight three-dimensional (3D) iron oxide frameworks with two different types of nanoscopic pores and tunable surface properties. This superparamagnetic material can be cut into arbitrary shapes and is suitable for applications such as multiphase catalysis and the removal of heavy metal ions and oil from water.


Materials with hierarchically organized pore systems—meaning that the walls of macropores with diameters in the micrometer range contain mesopores of just a few nanometers—are high on the wish lists of materials researchers. The advantages of these materials include their high surface area and the easy accessibility of the small pores through the larger ones. The great desirability of these materials is matched by the degree of difficulty in producing them on an industrial scale.

Scientists at Fudan University (China) and Monash University (Australia) have now successfully produced an ultralight iron oxide framework with 250 µm and 18 nm pores in a process that can be used on an industrial scale.

A team led by Gengfeng Zheng and Dongyuan Zhao used highly porous polyurethane sponges as a “matrix”, which were soaked with yellow potassium hexacyanoferrate (K4[Fe(CN)6]). Subsequent hydrolysis resulted in cubic nanocrystals of Prussian blue (iron hexacyanoferrate), a dark blue pigment, which were deposited all over the surfaces of the sponge.

The polyurethane sponge was then fully burned away through pyroloysis and the Prussian blue was converted to iron oxide. The result is a 3D framework of iron oxide cubes that are in turn made of iron oxide nanoparticles and contain mesopores. The material is so light that the researchers were able to balance a 240 cm3 piece on an oleander blossom.

Simple modifications allow the surface of the 3D framework to be varied from strongly hydrophilic to strongly hydrophobic for different applications. The researchers demonstrated this by removing arsenic ions from contaminated water and by separating water from gasoline. In the latter experiment, the resol-coated iron oxide framework absorbed more than 150 times of its own weight in gasoline.

The resol-coated frameworks are also suitable for use as nanoreactors for catalytic multiphase reactions between hydrophilic and hydrophobic reactants, which can normally only be made miscible through addition of various phase-transfer reagents and cosolvents. With the resol-coated iron oxide framework, the reaction runs much faster and more selectively without these additives, giving high yields. This is because of the tunable hydrophilic/hydrophobic surfaces of the mesopores, which take in both reagents and bring them into contact with each other. The catalyst can be retrieved magnetically, because the iron oxide nanoparticles of the 3D frameworks are superparamagnetic.

Author: Dongyuan Zhao, Fudan University, Shanghai (China), http://www.mesogroup.fudan.edu.cn/

Title: Ultralight Mesoporous Magnetic Frameworks by Interfacial Assembly of Prussian Blue Nanocubes

Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201308625 

Dongyuan Zhao | Angewandte Chemie
Further information:
http://pressroom.angewandte.org

Further reports about: Interfacial Iron Oxide gasoline hydrophilic hydrophobic materials nanoparticles pores porous sponge superparamagnetic surfaces

More articles from Life Sciences:

nachricht Scientists spin artificial silk from whey protein
24.01.2017 | Deutsches Elektronen-Synchrotron DESY

nachricht Choreographing the microRNA-target dance
24.01.2017 | UT Southwestern Medical Center

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Scientists spin artificial silk from whey protein

X-ray study throws light on key process for production

A Swedish-German team of researchers has cleared up a key process for the artificial production of silk. With the help of the intense X-rays from DESY's...

Im Focus: Quantum optical sensor for the first time tested in space – with a laser system from Berlin

For the first time ever, a cloud of ultra-cold atoms has been successfully created in space on board of a sounding rocket. The MAIUS mission demonstrates that quantum optical sensors can be operated even in harsh environments like space – a prerequi-site for finding answers to the most challenging questions of fundamental physics and an important innovation driver for everyday applications.

According to Albert Einstein's Equivalence Principle, all bodies are accelerated at the same rate by the Earth's gravity, regardless of their properties. This...

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Breaking the optical bandwidth record of stable pulsed lasers

24.01.2017 | Physics and Astronomy

Choreographing the microRNA-target dance

24.01.2017 | Life Sciences

Spanish scientists create a 3-D bioprinter to print human skin

24.01.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>