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 Small parts make the difference
12.01.2016 | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP

nachricht Nanopores could take the salt out of seawater
12.11.2015 | University of Illinois at Urbana-Champaign

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: Automated driving: Steering without limits

OmniSteer project to increase automobiles’ urban maneuverability begins with a € 3.4 million budget

Automobiles increase the mobility of their users. However, their maneuverability is pushed to the limit by cramped inner city conditions. Those who need to...

Im Focus: Microscopy: Nine at one blow

Advance in biomedical imaging: The University of Würzburg's Biocenter has enhanced fluorescence microscopy to label and visualise up to nine different cell structures simultaneously.

Fluorescence microscopy allows researchers to visualise biomolecules in cells. They label the molecules using fluorescent probes, excite them with light and...

Im Focus: NASA's ICESat-2 equipped with unique 3-D manufactured part

NASA's follow-on to the successful ICESat mission will employ a never-before-flown technique for determining the topography of ice sheets and the thickness of sea ice, but that won't be the only first for this mission.

Slated for launch in 2018, NASA's Ice, Cloud and land Elevation Satellite-2 (ICESat-2) also will carry a 3-D printed part made of polyetherketoneketone (PEKK),...

Im Focus: Sinking islands: Does the rise of sea level endanger the Takuu Atoll in the Pacific?

In the last decades, sea level has been rising continuously – about 3.3 mm per year. For reef islands such as the Maldives or the Marshall Islands a sinister picture is being painted evoking the demise of the island states and their cultures. Are the effects of sea-level rise already noticeable on reef islands? Scientists from the ZMT have now answered this question for the Takuu Atoll, a group of Pacific islands, located northeast of Papua New Guinea.

In the last decades, sea level has been rising continuously – about 3.3 mm per year. For reef islands such as the Maldives or the Marshall Islands a sinister...

Im Focus: Energy-saving minicomputers for the ‘Internet of Things’

The ‘Internet of Things’ is growing rapidly. Mobile phones, washing machines and the milk bottle in the fridge: the idea is that minicomputers connected to these will be able to process information, receive and send data. This requires electrical power. Transistors that are capable of switching information with a single electron use far less power than field effect transistors that are commonly used in computers. However, these innovative electronic switches do not yet work at room temperature. Scientists working on the new EU research project ‘Ions4Set’ intend to change this. The program will be launched on February 1. It is coordinated by the Helmholtz-Zentrum Dresden-Rossendorf (HZDR).

“Billions of tiny computers will in future communicate with each other via the Internet or locally. Yet power consumption currently remains a great obstacle”,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

AKL’16: Experience Laser Technology Live in Europe´s Largest Laser Application Center!

02.02.2016 | Event News

From intelligent knee braces to anti-theft backpacks

26.01.2016 | Event News

DATE 2016 Highlighting Automotive and Secure Systems

26.01.2016 | Event News

 
Latest News

A new potential biomarker for cancer imaging

05.02.2016 | Life Sciences

Graphene is strong, but is it tough?

05.02.2016 | Materials Sciences

Tiniest Particles Shrink Before Exploding When Hit With SLAC's X-ray Laser

05.02.2016 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>