Featured Research

from universities, journals, and other organizations

Reducing ion exchange particles to nano-size shows big potential

Date:
January 30, 2012
Source:
DOE/Savannah River National Laboratory
Summary:
Researchers have successfully shown that they can replace useful little particles of an ion exchange material with even tinier nano-sized particles, making them even more useful for a variety of applications.

Sometimes bigger isn't better. Researchers at the U.S. Department of Energy's Savannah River National Laboratory have successfully shown that they can replace useful little particles of monosodium titanate (MST) with even tinier nano-sized particles, making them even more useful for a variety of applications.

MST is an ion exchange material used to decontaminate radioactive and industrial wastewater solutions, and has been shown to be an effective way to deliver metals into living cells for some types of medical treatment. Typically, MST, and a modified form known as mMST developed by SRNL and Sandia National Laboratories, are in the form of fine powders, spherically-shaped particles about 1 to 10 microns in diameter (a micron is one-millionth of a meter).

"By making each particle smaller," says Dr. David Hobbs of SRNL, lead of the research project, "you increase the amount of surface area, compared to the overall volume of the particle. Since the particle surface is where reactions take place, you've increased the MST's working area." For example, a 10-nanometer particle has a surface area-to-volume ratio that is 1000 times that of a 10-micron particle. Thus, this project sought to synthesize titanate materials that feature nano-scale particle sizes (1 -- 200 nm). After successfully synthesizing nanosize titanates, the team investigated and found that the smaller particles do indeed exhibit good ion exchange characteristics. They also serve as photocatalysts for the decomposition of organic contaminants and are effective platforms for the delivery of therapeutic metals.

Dr. Hobbs and his partners in the project examined three methods of producing nano-sized particles, resulting in three different shapes. One is a sol-gel method, similar to the process used to produce "normal" micron-sized MST particles, but using surfactants and dilute concentrations of reactive chemicals to control particle size. This method resulted in spherical particles about 100 -- 150 nm in diameter.

A second method started with typical micron-sized particles, then delaminated and "unzipped" them to produce fibrous particles about 10 nm in diameter and 100 -- 150 nm long. The third method, which had been previously reported in the scientific literature, was a hydrothermal technique that produced nanotubes with a diameter of about 10 nm and lengths of about 100 -500 nm.

The team had considerable expertise in working with MST, having previously modified it with peroxide to form mMST, which exhibits enhanced performance in removing certain contaminants from radioactive waste and delivering metals for medical treatment. Nanosize MST produced by all three methods was successfully converted to the peroxide-modified form. As with micron-sized titanates, the peroxide-modified nanosize titanates exhibit a yellow color. The intensity of the yellow color appeared less intense with the hydrothermally produced nanotubes, suggesting the chemically resistant surface of the nanotubes may limit conversion to mMST.

Testing confirmed that the materials function as effective ion exchangers. For example, the spherical nanoMST and nanotube samples and their respective peroxide-modified forms remove strontium and actinides from alkaline high-level waste radioactive waste. Under weakly acidic conditions, the nanosize titanates and peroxotitanates removed more than 90% of 17 different metal ions.

The "unzipped" titanates and their peroxide-modified forms proved to be particularly good photocatalysts for the decomposition of organic contaminants.

Screening in-vitro tests showed that both nano-size and micron-size metal-exchanged titanates inhibit the growth of a number of oral cancer and bacterial cell lines. The mechanism of inhibition is not known, but preliminary scanning electron microscopy results suggest that the titanates may be interacting directly with the wall of the nucleus to deliver sufficient metal ion concentration to the cell nucleus to inhibit cell replication.

In addition to Dr. Hobbs, the team included M. C. Elvington, M. H. Tosten, K. M. L. Taylor-Pashow of SRNL; J. Wataha of the University of Washington; and M. D. Nyman of Sandia National Laboratories.

This work was funded under SRNL's Laboratory Directed Research & Development program, which supports highly innovative and exploratory research aligned with the Laboratory's priorities.


Story Source:

The above story is based on materials provided by DOE/Savannah River National Laboratory. Note: Materials may be edited for content and length.


Cite This Page:

DOE/Savannah River National Laboratory. "Reducing ion exchange particles to nano-size shows big potential." ScienceDaily. ScienceDaily, 30 January 2012. <www.sciencedaily.com/releases/2012/01/120130172609.htm>.
DOE/Savannah River National Laboratory. (2012, January 30). Reducing ion exchange particles to nano-size shows big potential. ScienceDaily. Retrieved April 17, 2014 from www.sciencedaily.com/releases/2012/01/120130172609.htm
DOE/Savannah River National Laboratory. "Reducing ion exchange particles to nano-size shows big potential." ScienceDaily. www.sciencedaily.com/releases/2012/01/120130172609.htm (accessed April 17, 2014).

Share This



More Matter & Energy News

Thursday, April 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

German Researchers Crack Samsung's Fingerprint Scanner

German Researchers Crack Samsung's Fingerprint Scanner

Newsy (Apr. 16, 2014) German researchers have used a fake fingerprint made from glue to bypass the fingerprint security system on Samsung's new Galaxy S5 smartphone. Video provided by Newsy
Powered by NewsLook.com
Porsche CEO Says Supercar Is Not Dead: Cue the Spyder 918

Porsche CEO Says Supercar Is Not Dead: Cue the Spyder 918

TheStreet (Apr. 16, 2014) The Porsche Spyder 918 proves that, in an automotive world obsessed with fuel efficiency, the supercar is not dead. Porsche North America CEO Detlev von Platen attributes the brand's consistent sales growth -- 21% in 2013 -- with an investment in new technology and expanded performance dynamics. The hybrid Spyder 918 has 887 horsepower and 944 lb-ft of torque, but it can run 18 miles on just an electric charge. The $845,000 vehicle is not a consumer-targeted vehicle but a brand statement. Video provided by TheStreet
Powered by NewsLook.com
Industry's Optimism Shines At New York Auto Show

Industry's Optimism Shines At New York Auto Show

Newsy (Apr. 16, 2014) After seeing auto sales grow last month, there's plenty for the industry to celebrate as it rolls out its newest designs. Video provided by Newsy
Powered by NewsLook.com
Ford Mustang Fetes Its 50th Atop Empire State Building

Ford Mustang Fetes Its 50th Atop Empire State Building

AFP (Apr. 16, 2014) Ford celebrated the 50th birthday of its beloved Mustang by displaying a new model of the convertible on top of the Empire State Building in New York. Duration: 00:28 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins