Miracle cure made from plants and recycled paper
All industrial nations need large volumes of oil which is normally delivered by ocean-going tankers or via inland waterways to its destination.
The most environmentally-friendly way of cleaning up nature after an oil spill accident is to absorb and recover the floating film of oil. The Empa researchers Tanja Zimmermann and Philippe Tingaut, in collaboration with Gilles Sèbe from the University of Bordeaux, have now succeeded in developing a highly absorbent material which separates the oil film from the water and can then be easily recovered, “silylated” nanocellulose sponge.
In laboratory tests the sponges absorbed up to 50 times their own weight of mineral oil or engine oil. They kept their shape to such an extent that they could be removed with pincers from the water. The next step is to fine tune the sponges so that they can be used not only on a laboratory scale but also in real disasters. To this end, a partner from the industry is currently sought.
One step production – from cellulose plants
Nanofibrillated Cellulose (NFC), the basic material for the sponges, is extracted from cellulose-containing materials like wood pulp, agricultural by products (such as straw) or waste materials (such as recycled paper) by adding water to them and pressing the aqueous pulp through several narrow nozzles at high pressure. This produces a suspension with gel-like properties containing long and interconnected cellulose nanofibres.
When the water from the gel is replaced with air by freeze-drying, a nanocellulose sponge is formed which absorbs both water and oil. This pristine material sinks in water and is thus nott useful for the envisaged purpose.
The Empa researchers have succeeded in modifying the chemical properties of the nanocellulose in just one process step by admixing a reactive alkoxysilane moleculein the gel before freeze-drying. The nanocellulose sponge loses its hydrophilic properties, is no longer suffused with water and only binds with oily substances.
In the laboratory the “silylated” nanocellulose sponge absorbed test substances like engine oil, silicone oil, ethanol, acetone or chloroform within seconds. Nanofibrillated cellulose sponge, therefore, reconciles several desirable properties: it is absorbent, floats reliably on water even when fully saturated and is biodegradable.
Download images at https://flic.kr/s/aHsjX9EZTh
Rainer Klose | newswise
Two decades of training students and experts in tracking infectious disease
27.11.2015 | Hochschule für Angewandte Wissenschaften Hamburg
Increased carbon dioxide enhances plankton growth, opposite of what was expected
27.11.2015 | Bigelow Laboratory for Ocean Sciences
Planet Earth experienced a global climate shift in the late 1980s on an unprecedented scale, fuelled by anthropogenic warming and a volcanic eruption, according to new research published this week.
Scientists say that a major step change, or ‘regime shift’, in the Earth’s biophysical systems, from the upper atmosphere to the depths of the ocean and from...
The Fraunhofer Institute for Solar Energy Systems ISE has installed 70 photovoltaic modules on the outer façade of one of its lab buildings. The modules were...
Nerve cells cover their high energy demand with glucose and lactate. Scientists of the University of Zurich now provide new support for this. They show for the first time in the intact mouse brain evidence for an exchange of lactate between different brain cells. With this study they were able to confirm a 20-year old hypothesis.
In comparison to other organs, the human brain has the highest energy requirements. The supply of energy for nerve cells and the particular role of lactic acid...
In laser material processing, the simulation of processes has made great strides over the past few years. Today, the software can predict relatively well what will happen on the workpiece. Unfortunately, it is also highly complex and requires a lot of computing time. Thanks to clever simplification, experts from Fraunhofer ILT are now able to offer the first-ever simulation software that calculates processes in real time and also runs on tablet computers and smartphones. The fast software enables users to do without expensive experiments and to find optimum process parameters even more effectively.
Before now, the reliable simulation of laser processes was a job for experts. Armed with sophisticated software packages and after many hours on computer...
Researchers at Heidelberg University have devised a new way to study the phenomenon of magnetism. Using ultracold atoms at near absolute zero, they prepared a...
25.11.2015 | Event News
17.11.2015 | Event News
21.10.2015 | Event News
27.11.2015 | Press release
27.11.2015 | Life Sciences
27.11.2015 | Materials Sciences