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 Fish Oil-Diet Benefits May be Mediated by Gut Microbes
28.08.2015 | University of Gothenburg

nachricht Bio-fabrication of Artificial Blood Vessels with Laser Light
28.08.2015 | Fraunhofer-Institut für Lasertechnik ILT

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: OU astrophysicist and collaborators find supermassive black holes in quasar nearest Earth

A University of Oklahoma astrophysicist and his Chinese collaborator have found two supermassive black holes in Markarian 231, the nearest quasar to Earth, using observations from NASA's Hubble Space Telescope.

The discovery of two supermassive black holes--one larger one and a second, smaller one--are evidence of a binary black hole and suggests that supermassive...

Im Focus: What would a tsunami in the Mediterranean look like?

A team of European researchers have developed a model to simulate the impact of tsunamis generated by earthquakes and applied it to the Eastern Mediterranean. The results show how tsunami waves could hit and inundate coastal areas in southern Italy and Greece. The study is published today (27 August) in Ocean Science, an open access journal of the European Geosciences Union (EGU).

Though not as frequent as in the Pacific and Indian oceans, tsunamis also occur in the Mediterranean, mainly due to earthquakes generated when the African...

Im Focus: Self-healing landscape: landslides after earthquake

In mountainous regions earthquakes often cause strong landslides, which can be exacerbated by heavy rain. However, after an initial increase, the frequency of these mass wasting events, often enormous and dangerous, declines, in fact independently of meteorological events and aftershocks.

These new findings are presented by a German-Franco-Japanese team of geoscientists in the current issue of the journal Geology, under the lead of the GFZ...

Im Focus: FIC Proteins Send Bacteria Into Hibernation

Bacteria do not cease to amaze us with their survival strategies. A research team from the University of Basel's Biozentrum has now discovered how bacteria enter a sleep mode using a so-called FIC toxin. In the current issue of “Cell Reports”, the scientists describe the mechanism of action and also explain why their discovery provides new insights into the evolution of pathogens.

For many poisons there are antidotes which neutralize their toxic effect. Toxin-antitoxin systems in bacteria work in a similar manner: As long as a cell...

Im Focus: Fraunhofer IPA develops prototype of intelligent care cart

It comes when called, bringing care utensils with it and recording how they are used: Fraunhofer IPA is developing an intelligent care cart that provides care staff with physical and informational support in their day-to-day work. The scientists at Fraunhofer IPA have now completed a first prototype. In doing so, they are continuing in their efforts to improve working conditions in the care sector and are developing solutions designed to address the challenges of demographic change.

Technical assistance systems can improve the difficult working conditions in residential nursing homes and hospitals by helping the staff in their work and...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Networking conference in Heidelberg for outstanding mathematicians and computer scientists

20.08.2015 | Event News

Scientists meet in Münster for the world’s largest Chitin und Chitosan Conference

20.08.2015 | Event News

Large agribusiness management strategies

19.08.2015 | Event News

 
Latest News

Interstellar seeds could create oases of life

28.08.2015 | Physics and Astronomy

An ounce of prevention: Research advances on 'scourge' of transplant wards

28.08.2015 | Health and Medicine

Fish Oil-Diet Benefits May be Mediated by Gut Microbes

28.08.2015 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>