In an effort to create a more viable material for drug delivery, a team of researchers has accidentally created an entirely new material thought for more than 100 years to be impossible to make. Upsalite is a new form of non-toxic magnesium carbonate with an extremely porous surface area which allows it to absorb more moisture at low humidities than any other known material. "The total area of the pore walls of one gram of material would cover 800 square meters (8611 sq ft) if you would 'roll them out'", Maria Strømme, Professor of Nanotechnology at the Uppsala University, Sweden tells Gizmag. That's roughly equal to the sail area of a megayacht. Aside from using substantially less energy to create drier environments for producing electronics, batteries and pharmaceuticals, Upsalite could also be used to clean up oil spills, toxic waste and residues.
Scientists have long puzzled over this particular form of magnesium carbonate since it doesn't normally occur in nature and has defied synthesis in laboratories. Until now, its properties have remained a mystery. Strømme confesses that they didn't actually set out to create it. "We were really into making a porous calcium carbonate for drug delivery purposes and wanted to try to make a similarly porous magnesium carbonate since we knew that magnesium carbonate was non-toxic and already approved for drug delivery," she tells us. "We tried to use the same process as with the calcium carbonate, totally unaware of the fact that researchers had tried to make disordered magnesium carbonates for many decades using this route without succeeding."
The breakthrough came when they tweaked the process a little and accidentally left the material in the reaction chamber over a weekend. On their return they found a new gel in place. "We realized that the material we had made was one that had been claimed impossible to make," Strømme adds. A year spent refining the process gave them Upsalite.
While creating a theoretical material sounds like cause for celebration, Strømme says the major scientific breakthrough is to be found in its amazing properties. No other known carbonate has a surface area as large as 800 sq m per gram. Though scientists have created many new high surface area materials with nanotechnology, such as carbon nanotubes and zeolites, what makes Upsalite special is the minuteness of its nanopores.
Each nanopore is less than 10 nanometers in diameter which results in one gram of the material having a whopping 26 trillion nanopores. "If a material has many small pores," explains Strømme, "it gives the material a very large surface area per gram, which gives the material many reaction sites, i.e. sites that can react with the environment, with specific chemicals, or in the case of Upsalite, with moisture."
Upsalite's moisture absorption properties are striking. It was found to absorb 20 times more moisture than fumed silica, a material used for cat box fillers and as an anti-caking agent for moisture control during the transport of moisture sensitive goods. This means that you'd need 20 times less material to do the moisture control job.
Its unique pore structure also opens up new applications in drug delivery. The pores can host drugs that need protection from the environment before being delivered to the human body. It's also useful in thermal insulation, drying residues from oil and gas industries, and as a dessicant for humidity control. Potential applications are still being discovered as the material undergoes development for industrial use.
The team at Uppsala University is commercializing Upsalite through their spin-off company Disruptive Materials. An article describing the material and its properties can be found at PLOS ONE.
Source: Disruptive Materials
