Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Pesticide additives cause drifting droplets, but can be controlled

21.03.2012
Chemical additives that help agricultural pesticides adhere to their targets during spraying can lead to formation of smaller "satellite" droplets that cause those pesticides to drift into unwanted areas, Purdue University researchers have found.
Carlos Corvalan, an associate professor of food science, said understanding how the additives work together means they could be designed to decrease the health, environmental and property damage risks caused by drift. Corvalan; Osvaldo Campanella, a Purdue professor of agricultural and biological engineering; and Paul E. Sojka, a Purdue professor of mechanical engineering, published their results in a February issue of the journal Chemical Engineering Science.

"When we spray liquids, we have what we call main drops, which are drops of the desired size, and we can also have smaller satellite drops. The smaller drops move easily by wind and travel long distances," Corvalan said. "Now that we know better how additives influence the formation of satellite droplets, we can control their formation."

The research will also have applications in food processing and rocket propulsion, where drop sizes are important.

When liquids are sprayed, they start in a stream and eventually form drops. As the liquids move farther in the air, drops connected by a thin filament start to pull apart. That filament eventually detaches and becomes part of the drops that were forming on either side of it.

Satellite droplets form in the middle of filaments of pesticides containing surfactants and polymeric additives, which help the pesticides wet and adhere to plant surfaces. The surfactants reduce surface tension and force round drops to flatten, helping them cover more surface area on a sprayed plant's leaves. The polymeric additives reduce viscosity – liquid resistance – making the pesticide flow easier. Polymeric additives also keep the drops from bouncing off plant surfaces.

"Each additive is designed to improve the characteristics of the main drops," Corvalan said. "But there is a side effect."

When both additives are present in a pesticide, the surfactant pushes more liquid toward the filament. The reduced viscosity allows liquid to flow more easily in that direction, resulting in a well-defined satellite drop forming in the filament.

"When you put both additives together, there is a synergistic effect. The force induced by the surfactant that was opposed by viscosity is no longer so strongly opposed, and this combined effect can result in the formation of satellite droplets," Corvalan said.

Drifting of agricultural pesticides not only increases waste and cost for farmers but also can cause health, environmental and property damage, according to the U.S. Environmental Protection Agency.

The results show that carefully modulating the strength, concentration or ratio of surfactants to polymer additives can mitigate or eliminate the formation of unwanted satellite droplets.

Corvalan is now transferring the results obtained from agricultural research into food processing and rocket propulsion work. He said drop size uniformity is as important for fuels sprayed into rocket combustion chambers as for the production of food emulsions.

The U.S. Department of Agriculture National Institute of Food and Agriculture, Air Quality Program, and the Army Research Office funded the work.

Simulations and high-speed visualization reveal a synergistic effect between chemical additives that can lead to the formation of satellite droplets during crop spraying. Emission of satellite droplets - shown here between two main drops - is also detrimental in a number of applications ranging from food processing to rocket propulsion systems. (Purdue University image)

Writer: Brian Wallheimer, 765-496-2050, bwallhei@purdue.edu

Source: Carlos Corvalan, 765-494-8262, corvalac@purdue.edu

Ag Communications: (765) 494-2722;
Keith Robinson, robins89@purdue.edu
Agriculture News Page

Brian Wallheimer | EurekAlert!
Further information:
http://www.purdue.edu

More articles from Agricultural and Forestry Science:

nachricht How much drought can a forest take?
20.01.2017 | University of California - Davis

nachricht Plasma-zapping process could yield trans fat-free soybean oil product
02.12.2016 | Purdue University

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>