Tag Archives: Albert Mihranyan

Removing viruses from water with a ‘mille-feuille’ filter

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Mille-feuille is a pastry and it’s name translates to ‘a thousand leaves’, which hints at how a ‘mille-feuille’ nanofilter is constructed. From a May 18, 2016 news item on Nanowerk,

A simple paper sheet made by scientists at Uppsala University can improve the quality of life for millions of people by removing resistant viruses from water. The sheet, made of cellulose nanofibers, is called the mille-feuille filter as it has a unique layered internal architecture resembling that of the French puff pastry mille-feuille (Eng. thousand leaves).

Caption: The sheet made of cellulose nanofibers in the mille-feuille filter which can remove resistant viruses from water. Research led by Albert Mihranyan, Professor of Nanotechnology at Uppsala University, Image by Simon Gustafsson. Credit: Simon Gustafsson

Caption: The sheet made of cellulose nanofibers in the mille-feuille filter which can remove resistant viruses from water. Research led by Albert Mihranyan, Professor of Nanotechnology at Uppsala University, Image by Simon Gustafsson. Credit: Simon Gustafsson

A May 18, 2016 Uppsala University (Sweden) press release on EurekAlert, which originated the news item, expands on the theme,

With a filter material directly from nature, and by using simple production methods, we believe that our filter paper can become the affordable global water filtration solution and help save lives. Our goal is to develop a filter paper that can remove even the toughest viruses from water as easily as brewing coffee’, says Albert Mihranyan, Professor of Nanotechnology at Uppsala University, who heads the study.

Access to safe drinking water is among the UN’s Sustainable Development Goals. More than 748 million people lack access to safe drinking water and basic sanitation. Water-borne infections are among the global causes for mortality, especially in children under age of five, and viruses are among the most notorious water-borne infectious microorganisms. They can be both extremely resistant to disinfection and difficult to remove by filtration due to their small size.

Today we heavily rely on chemical disinfectants, such as chlorine, which may produce toxic by-products depending on water quality. Filtration is a very effective, robust, energy-efficient, and inert method of producing drinking water as it physically removes the microorganisms from water rather than inactivates them. But the high price of efficient filters is limiting their use today.

‘Safe drinking water is a problem not only in the low-income countries. Massive viral outbreaks have also occurred in Europe in the past, including Sweden, continues Mihranyan referring to the massive viral outbreak in Lilla Edet municipality in Sweden in 2008, when more than 2400 people or almost 20% of the local population got infected with Norovirus due to poor water. ‘ Cellulose is one of the most common filtering media used in daily life from tea-bags to vacuum cleaners. However, the general-purpose filter paper has too large pores to remove viruses. In 2014, the group has described for the first time a paper filter that can remove large size viruses, such as influenza virus.

Small size viruses have been much harder to get rid of, as they are extremely resistant to physical and chemical inactivation. A successful filter should not only remove viruses but also feature high flow, low fouling, and long life-time, which makes advanced filters very expensive to develop. Now, with the breakthrough achieved using the mille-feuille filter the long awaited shift to affordable advanced filtration solutions may at last become a reality. Another application of the filter includes production of therapeutic proteins and vaccines.

Here’s a link to and a citation for the paper,

Mille-feuille paper: a novel type of filter architecture for advanced virus separation applications by Simon Gustafsson, Pascal Lordat, Tobias Hanrieder, Marcel Asper,  Oliver Schaeferb, and Albert Mihranyan, Mater. Horiz., 2016, Advance Article DOI: 10.1039/C6MH00090H First published online 18 May 2016

This paper is behind a paywall.

Upsalite, an impossible material from Uppsala University (Sweden) and Disruptive Materials

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You can feel the researchers’ excitement crackling from the July 18, 2013 news release (English language version available at Uppsala University [Sweden]) about a new material that shares properties with zeolite, mesoporous silica, and carbon nanotubes and has some special properties all its own,

A novel material with world record breaking surface area and water adsorption abilities has been synthesized by researchers from Uppsala University, Sweden. The results are published today in PLOS ONE.

The magnesium carbonate material that has been given the name Upsalite is foreseen to reduce the amount of energy needed to control environmental moisture in the electronics and drug formulation industry as well as in hockey rinks and warehouses. It can also be used for collection of toxic waste, chemicals or oil spill and in drug delivery systems, for odor control and sanitation after fire.

Apparently this work represents a break with orthodoxy, from the news release,

-In contrast to what has been claimed for more than 100 years in the scientific literature, we have found that amorphous magnesium carbonate can be made in a very simple, low-temperature process, says Johan Forsgren, researcher at the Nanotechnology and Functional Materials Division

While ordered forms of magnesium carbonate, both with and without water in the structure, are abundant in nature, water-free disordered forms have been proven extremely difficult to make. In 1908, German researchers claimed that the material could indeed not be made in the same way as other disordered carbonates, by bubbling CO2 through an alcoholic suspension. Subsequent studies in 1926 and 1961 came to the same conclusion.

-A Thursday afternoon in 2011, we slightly changed the synthesis parameters of the earlier employed unsuccessful attempts, and by mistake left the material in the reaction chamber over the weekend. Back at work on Monday morning we discovered that a rigid gel had formed and after drying this gel we started to get excited, says Johan Forsgren.

A year of detailed materials analysis and fine tuning of the experiment followed.

-One of the researchers got to take advantage of his Russian skill since some of the chemistry details necessary for understanding the reaction mechanism was only available in an old Russian PhD thesis.

-After having gone through a number of state of the art materials characterization techniques it became clear that we had indeed synthesized the material that previously had been claimed impossible to make, says Maria Strømme, professor of nanotechnology and head of the nanotechnology and functional materials division. The most striking discovery was, however, not that we had produced a new material but it was instead the striking properties we found that this novel material possessed. It turned out that Upsalite had the highest surface area measured for an alkali earth metal carbonate; 800 square meters per gram. This places the new material in the exclusive class of porous, high surface area materials including mesoporous silica, zeolites, metal organic frameworks, and carbon nanotubes, says Strømme.

In addition we found that the material was filled with empty pores all having a diameter smaller than 10 nano meters. This pore structure gives the material a totally unique way of interacting with the environment leading to a number of properties important for application of the material. Upsalite is for example found to absorb more water at low relative humidities than the best materials presently available; the hydroscopic zeolites, a property that can be regenerated with less energy consumption than is used in similar processes today.

This, together with other unique properties of the discovered impossible material is expected to pave the way for new sustainable products in a number of industrial applications, says Maria Strømme.

The discovery will be commercialized though the University spin-out company Disruptive Materials (www.disruptivematerials.com) that has been formed by the researchers together with the holding company of Uppsala University

Here’s a link to and a citation for the researchers’ published paper,

A Template-Free, Ultra-Adsorbing, High Surface Area Carbonate Nanostructure by Johan Forsgren, Sara Frykstrand, Kathryn Grandfield, Albert Mihranyan, and Maria Strømme. PLoS ONE, 2013; 8 (7): e68486 DOI: 10.1371/journal.pone.0068486

Here’s a little more abut Upsalite from the university’s spin-off company, Disruptive Materials homepage,

 Upsalite
A new material with world record breaking surface area and water adsorption abilities

It was supposed to be impossible, but… We did it! Disruptive Materials has succeeded to manufacture micro-porous magnesium carbonate and the properties are mind blowing. Over 800 m2/g in surface area, better water adsorbtion ability than the former champion Zeolite Y and a very low manufacturing cost. We have been testing the material for a long time, and we see new applications every week for this new and true super-material.

Finally for those with Swedish language skills, here’s the July 18, 2013 news release from Disruptive Materials.