Anti-clumping strategy for nanoparticles

October 16, 2015

Nanoparticles are ubiquitous in industrial applications ranging from drug delivery and biomedical diagnostics to developing hydrophobic surfaces, lubricant additives and enhanced oil recovery solutions in petroleum fields. For such nanoparticles to be effective, they need to remain well dispersed into the fluid surrounding them. In a study published in EPJ B, Brazilian physicists identified the conditions that lead to instability of nanoparticles and producing aggregates. This happens when the electric force on their surface no longer balances by the sum of the attractive or repulsive forces between nanoparticles. These findings were recently published by Lucas de Lara from the Centre for Natural and Human Sciences, at the University Federal of ABC (UFABC) in Santo André, SP, Brazil and colleagues.

The authors studied silica nanoparticles that do not react with their surroundings in a solution containing two types of salts, table salt and calcium chloride. They then attached an ending to the nanoparticles, a process called functionalisation. Featuring endings that are hydrophilic or hydrophobic can help nanoparticles remain dispersed.

They then varied the temperature and salt concentration and monitored the ion dispersion in the salty solution. In some cases, they observed the accumulation of ions around nanoparticles, leading to the formation of an electric double-layer around the nanoparticles in otherwise overall electrically neutral nanoparticle suspensions.

De Lara and colleagues then determined the factor influencing the stability of such nanoparticles in solutions. Their simulations suggest that the instability of functionalised nanoparticles dispersion in brine depends on several factors preceding their aggregation. The "culprits" include the formation of an electric double layer - observed to be greater for calcium chloride than for table salt - and the narrowing of that double layer. In addition, the considerable variation in the interface tension followed by a steep increase in ion mobility also contribute to instability. The group's findings on overall neutral nanoparticles are in line with previous work with electrically charged nanoparticles.
-end-
Reference: L. S. de Lara, V. A. Rigo, and C. R. Miranda (2015), The stability and interfacial properties of functionalized silica nanoparticles dispersed in brine studied by molecular dynamics, Eur. Phys. J. B 88:261, DOI: 10.1140/epjb/e2015-60543-1

For more information visit: http://www.epj.org

Springer

Related Nanoparticles Articles from Brightsurf:

An ionic forcefield for nanoparticles
Nanoparticles are promising drug delivery tools but they struggle to get past the immune system's first line of defense: proteins in the blood serum that tag potential invaders.

Phytoplankton disturbed by nanoparticles
Products derived from nanotechnology are efficient and highly sought-after, yet their effects on the environment are still poorly understood.

How to get more cancer-fighting nanoparticles to where they are needed
University of Toronto Engineering researchers have discovered a dose threshold that greatly increases the delivery of cancer-fighting drugs into a tumour.

Nanoparticles: Acidic alert
Researchers of Ludwig-Maximilians-Universitaet (LMU) in Munich have synthesized nanoparticles that can be induced by a change in pH to release a deadly dose of ionized iron within cells.

3D reconstructions of individual nanoparticles
Want to find out how to design and build materials atom by atom?

Directing nanoparticles straight to tumors
Modern anticancer therapies aim to attack tumor cells while sparing healthy tissue.

Sweet nanoparticles trick kidney
Researchers engineer tiny particles with sugar molecules to prevent side effect in cancer therapy.

A megalibrary of nanoparticles
Using straightforward chemistry and a mix-and-match, modular strategy, researchers have developed a simple approach that could produce over 65,000 different types of complex nanoparticles.

Dialing up the heat on nanoparticles
Rapid progress in the field of metallic nanotechnology is sparking a science revolution that is likely to impact all areas of society, according to professor of physics Ventsislav Valev and his team at the University of Bath in the UK.

Illuminating the world of nanoparticles
Scientists at the Okinawa Institute of Science and Technology Graduate University (OIST) have developed a light-based device that can act as a biosensor, detecting biological substances in materials; for example, harmful pathogens in food samples.

Read More: Nanoparticles News and Nanoparticles Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.