Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

How to count nanoparticles

10.10.2011
Nanoparticles of a substance can be counted and the size distribution can be determined by dispersing the nanoparticles into a gas. But some nanoparticles tend to aggregate when the surrounding conditions change. Scientists at the University of Gothenburg, Sweden, have shown that it is possible to sort and count the particles, even when they have formed aggregates.
"Nanoparticles are already used in many everyday products, such as sunscreen and cosmetics. It is important to be able to determine their size, shape and surface area, in order to be able to improve their properties within various areas of application", says Ann-Cathrin Johnsson of the Department of Chemistry at the University of Gothenburg.

A nanoparticle is a particle with a diameter that is much smaller than one millionth of a metre. Such small particles are not influenced by gravity and thus they do not fall to the bottom of a liquid or gas, and instead spread out throughout the container. Their area of contact with the surrounding medium is very large due to their small size, as a result many interesting properties arise. Nanoparticles of a substance behave, quite simply, differently than large particles of the same substance.

Certain types of nanoparticles can start to aggregate in special conditions, and sometimes a so called gel may form. The process is similar to that of boiling an egg: the proteins in the egg white aggregate and form the solid-like structure that we recognise as boiled egg.

Ann-Cathrin Johnsson's thesis work has studied one of these aggregating systems, colloidal silica. The gel that forms when salt is added to colloidal silica can be used, for example, to seal rock and to stabilise soil.

"I started with a method that had been used only for analysing nanoparticles that had not aggregated, and developed it further. Nanoparticles that have aggregated can be analysed individually if a colloidal silica gel, which contains these aggregated nanoparticles, is first diluted and then dispersed into the gas phase. If the samples are analysed immediately after being diluted, this method gives an accurate picture of the gelated system.

The thesis has been successfully defended.
For more information, please contact: Ann-Cathrin Johnsson
Telephone: +46 31 786 9067
Mobile: +46 70 225 5723
Email: ann-catrin.johnson@chem.gu.se

Helena Aaberg | idw
Further information:
http://www.gu.se
http://hdl.handle.net/2077/26662

More articles from Life Sciences:

nachricht Navigational view of the brain thanks to powerful X-rays
18.10.2017 | Georgia Institute of Technology

nachricht Separating methane and CO2 will become more efficient
18.10.2017 | KU Leuven

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Osaka university researchers make the slipperiest surfaces adhesive

18.10.2017 | Materials Sciences

Space radiation won't stop NASA's human exploration

18.10.2017 | Physics and Astronomy

Los Alamos researchers and supercomputers help interpret the latest LIGO findings

18.10.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>