Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New metal crystals, formed on a cotton assembly line

28.03.2007
First appearance of silver, gold, nickel and other tiny, uniform metal crystals have novel chemical and physical properties

Appropriating cellulose fibers from cotton and crystallizing them, scientists at Pacific Northwest National Laboratory have grown never-before-seen configurations of metal crystals that show promise as components in biosensors, biological imaging, drug delivery and catalytic converters.

Deriving the desired chemical and physical properties necessary for those applications hinges on the uniform size of the metal crystals. Depending on the metal, they must be between 2 and 200 nanometers, Yongsoon Shin, a staff scientist at the Department of Energy laboratory in Richland, Wash., reported Monday at the national meeting of the American Chemical Society. PNNL laboratory fellow Gregory Exarhos led the research.

Exarhos called Shin’s experimental work "the first report of the efficacy of nanocrystalline cellulose templates in driving the formation of ordered metal and metal oxide nanoparticles at surfaces." Exarhos has dubbed these cellulose nanocrystals "molecular factories."

... more about:
»Cellulose »catalytic »cotton »crystals »uniform

Using acid-treated cellulose fibers from cotton as a natural template, the PNNL team has been able to grow gold, silver, palladium, platinum, copper, nickel and other metal and metal-oxide nanocrystals quickly and of uniform size, Shin said. The metals display catalytic, electrical and optical that would not be present in larger or odd-sized crystals.

The acid converts the cellulose to a large, stable crystallized molecule rich in oxygen-hydrogen, or hydroxyl, groups, predictably spaced along the long chemical chains, or polymers, that comprise the cellulose molecule’s backbone. When most metal salts dissolved in solution are added in a pressurized oven and heated 70 to 200 degrees centigrade or warmer for four to 16 hours, uniform metal crystals form at the hydroxyl sites.

The researchers called this method a "green process," requiring only heat, the crystalline cellulose and the metal salts. Other attempts to get uniform nanometals have resulted in crystals of widely variable sizes that require strong, caustic chemicals as reducing and stabilizing agents.

"We have some preliminary catalytic results," Shin said, involving "coupling reactions of organic molecules for palladium and UV-irradiated degradation of organic dyes in water with selenium metals. "Smaller particles—15 to 20 nanometers—showed faster and higher catalytic conversion ratio compared to commercial catalysts."

Bill Cannon | EurekAlert!
Further information:
http://www.pnl.gov

Further reports about: Cellulose catalytic cotton crystals uniform

More articles from Life Sciences:

nachricht Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University

nachricht How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>