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 Dresdner scientists print tomorrow’s world
08.02.2017 | Fraunhofer-Institut für Werkstoff- und Strahltechnik IWS

nachricht New technology for mass-production of complex molded composite components
23.01.2017 | Evonik Industries AG

All articles from Process Engineering >>>

The most recent press releases about innovation >>>

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

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Researchers shoot for success with simulations of laser pulse-material interactions

29.03.2017 | Materials Sciences

Igniting a solar flare in the corona with lower-atmosphere kindling

29.03.2017 | Physics and Astronomy

As sea level rises, much of Honolulu and Waikiki vulnerable to groundwater inundation

29.03.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>