Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Flowing water energizes minerals

06.06.2014

Researchers from Mainz discover that liquid flow changes surface chemistry of minerals, with implications for geological sciences.

A collaborative research team from the Max Planck Institute for Polymer Research (MPIP) in Germany and the University of Namur in Belgium discovered a fundamental, yet unnoticed, phenomenon that motion of water along a mineral surface changes the charge of that surface. The researchers published their finding in Science.

The international research team in Mainz led by Mischa Bonn studied how moving water, like in riverbeds or creeks, affects mineral surfaces and their dissolution. Remarkably, water flow along fluorite and glass surfaces makes these surfaces more positively charged. In the case of fluorite, a 100-fold increase in acid concentration was required to induce similar effects in static water.

Water molecules as reporters

... more about:
»Polymer »Water »acid »experiments »ions »phenomenon »surfaces

Surfaces of minerals acquire a charge when immersed in water, as part of the minerals can be released from the surface as charged ions. This was known, but that moving water can change the surface charge was entirely unexpected. The research team in Mainz measured the surface charge of immersed minerals using the water molecules directly at the interface as reporters.

Water molecules have a positive and a negative end, and align toward the surface, depending on the surface charge. The interfacial water molecules were interrogated by overlapping two laser pulses of different color at the liquid-mineral interface, whereby a new color can be generated that provides extremely specific information about the interfacial region.

In this manner, both the orientation (pointing up- or downwards) and the number of oriented water molecules can be directly measured, which provides direct access to the surface charge.

The experiments show that flowing a liquid in contact with minerals induces a preferential dissolution of specific mineral constituents. In the case of fluorite, negatively charged ions are preferentially dissolved while positively charged ions remain at the mineral surface. The researchers were even able to show that the sign of the surface charge can be controlled with flow, so that water molecules could be made to reorient, depending on the presence or absence of flow.

The observed phenomenon seems to be rather ubiquitous in geology. Particularly because this phenomenon occurs not only for fluorite, but also for silica surfaces – silicates constitute more than half of the minerals in the earth crust. “These new insights on the fundamentals of mineral dissolution force us to reconsider well-established theories in weathering and environmental sciences to take into account changes in surface charge in addition to well-documented surface erosion.”, explains Mischa Bonn.

Contact 

Prof. Dr. Mischa Bonn

Director

Phone:+49 6131 379-161
Email:bonn@...

Homepage 

Publication

 
1
Dan Lis, Ellen H. G. Backus, Johannes Hunger, Sapun H. Parekh, and Mischa Bonn
Science, 6th June 2014; doi: 10.1126/science.1253793 

Prof. Dr. Mischa Bonn | Max Planck Institute for Polymer Research

Further reports about: Polymer Water acid experiments ions phenomenon surfaces

More articles from Process Engineering:

nachricht Intelligent wheelchairs, predictive prostheses
20.12.2017 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA

nachricht Jelly with memory – predicting the leveling of com-mercial paints
15.12.2017 | Fraunhofer-Institut für Produktionstechnik und Automatisierung IPA

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Artificial agent designs quantum experiments

On the way to an intelligent laboratory, physicists from Innsbruck and Vienna present an artificial agent that autonomously designs quantum experiments. In initial experiments, the system has independently (re)discovered experimental techniques that are nowadays standard in modern quantum optical laboratories. This shows how machines could play a more creative role in research in the future.

We carry smartphones in our pockets, the streets are dotted with semi-autonomous cars, but in the research laboratory experiments are still being designed by...

Im Focus: Scientists decipher key principle behind reaction of metalloenzymes

So-called pre-distorted states accelerate photochemical reactions too

What enables electrons to be transferred swiftly, for example during photosynthesis? An interdisciplinary team of researchers has worked out the details of how...

Im Focus: The first precise measurement of a single molecule's effective charge

For the first time, scientists have precisely measured the effective electrical charge of a single molecule in solution. This fundamental insight of an SNSF Professor could also pave the way for future medical diagnostics.

Electrical charge is one of the key properties that allows molecules to interact. Life itself depends on this phenomenon: many biological processes involve...

Im Focus: Paradigm shift in Paris: Encouraging an holistic view of laser machining

At the JEC World Composite Show in Paris in March 2018, the Fraunhofer Institute for Laser Technology ILT will be focusing on the latest trends and innovations in laser machining of composites. Among other things, researchers at the booth shared with the Aachen Center for Integrative Lightweight Production (AZL) will demonstrate how lasers can be used for joining, structuring, cutting and drilling composite materials.

No other industry has attracted as much public attention to composite materials as the automotive industry, which along with the aerospace industry is a driver...

Im Focus: Room-temperature multiferroic thin films and their properties

Scientists at Tokyo Institute of Technology (Tokyo Tech) and Tohoku University have developed high-quality GFO epitaxial films and systematically investigated their ferroelectric and ferromagnetic properties. They also demonstrated the room-temperature magnetocapacitance effects of these GFO thin films.

Multiferroic materials show magnetically driven ferroelectricity. They are attracting increasing attention because of their fascinating properties such as...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

10th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Münster, 10-11 April 2018

08.01.2018 | Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

 
Latest News

Thanks for the memory: NIST takes a deep look at memristors

22.01.2018 | Materials Sciences

Radioactivity from oil and gas wastewater persists in Pennsylvania stream sediments

22.01.2018 | Earth Sciences

Saarland University bioinformaticians compute gene sequences inherited from each parent

22.01.2018 | Life Sciences

VideoLinks Wissenschaft & Forschung
Overview of more VideoLinks >>>