Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

From the Ocean into the Reactor

19.11.2013
New sorbents efficiently extract uranium from seawater


Uranium mining for the nuclear industry causes immense environmental damage, which becomes more severe as reserves are depleted.

The isolation of uranium from seawater would be a much more environmentally friendly alternative. In the journal Angewandte Chemie, American researchers have now introduced a process by which they can produce tailored, highly effective adsorption agents to do this job.

Because the concentration of uranyl ions in seawater is very low, adsorption agents used for this process must be particularly efficient. By carefully controlling the surface and pore structures, a team from Oak Ridge National Laboratory and the University of Tennessee has now been able to significantly increase both the rate and capacity of adsorption of a new polymer adsorbent.

Their success stems from a special polymerization technique. Sheng Dai’s team begins by producing a porous polymer framework based on the monomer vinylbenzyl chloride (VBC) with divinylbenzene (DVB) as a cross-linking agent. It is possible to vary the surface properties and pore volume of the product by changing the ratio of VBC to DVB.

The interiors of the resulting frameworks contain many accessible chloride species that then serve as starting points for the next polymerization step, which is known as atom-transfer radical polymerization (ATRP).

This reaction allows the researchers to grow polyacrylonitrile chains within the framework. The advantage of ATRP is that the length of the chains is highly controllable and uniform. In the final step, the polyacrylonitrile is converted to polyamidoxime because amidoxime groups bind well to uranyl ions.

Tests with simulated seawater resulted in distinctly higher and significantly faster uranium adsorption than with conventional, polyethylene-based adsorbents. Experiments showed that the adsorption capacity of the new adsorbent is strongly dependent on the density of amidoxime groups—a parameter that can be tailored by means of the pore size and the number of accessible chloride species in the original nanoporous framework.

“These frameworks are the first example of ATRP initiators in which the initiator species is located within the nanoporous support network,” reports Dai. “This new process puts materials with tailored adsorption and surface properties within reach. The method can be used to produce a wide variety of polymer nanocomposites for applications including the removal of heavy-metal ions from solutions or novel catalysts.”

About the Author
Dr. Sheng Dai is currently a Group Leader of the Nanomaterials Chemistry Group at Oak Ridge National Laboratory (ORNL) and Professor of Chemistry at the University of Tennessee, Knoxville. He had made a number of important contributions to the fields of mesoporous materials and ionic liquids. Because of his outstanding research achievements, he was named a UT-Battelle Corporate Fellow in 2011, the highest designation a researcher can receive at ORNL.

Author: Sheng Dai, Oak Ridge National Laboratory (USA), http://web.ornl.gov/sci/csd/Research_areas/NC_staff.htm

Title: Seawater Uranium Sorbents: Preparation from a Mesoporous Copolymer Initiator by Atom-Transfer Radical Polymerization

Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201307825

Sheng Dai | Angewandte Chemie
Further information:
http://pressroom.angewandte.org.

Further reports about: Angewandte Chemie CHEMISTRY Pacific Ocean ionic liquid oxime group uranium

More articles from Life Sciences:

nachricht Microbial Communities for Health and Environment : Precise Measurements of Microbial Ecosystems
26.11.2014 | Universität Luxemburg - Université du Luxembourg

nachricht How various brain areas interact in decisions
26.11.2014 | Universität Zürich

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Anzeige

Anzeige

Event News

Regional economic cooperation in Central Asia

21.11.2014 | Event News

Educating the Ecucators

13.11.2014 | Event News

36th Annual IATUL Conference 2015: Call for papers and posters

12.11.2014 | Event News

 
Latest News

Siemens expands software for mobile data management in the process industry

26.11.2014 | Trade Fair News

Microbial Communities for Health and Environment : Precise Measurements of Microbial Ecosystems

26.11.2014 | Life Sciences

VTT demonstrates new technique for generating electricity

26.11.2014 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>