Defects in graphene membranes enable selective passage of molecules

Apr 26, 2017

Researchers from the Clemson Nanomaterials Institute and the Ural Federal University in Russia have discovered a way to make an extremely thin oxygen selective membrane using graphene. Such membranes allow only oxygen into Li-O2 batteries while stopping or slowing water vapor intake. This could impede corrosion caused by ambient water vapor from air and push forward the usability of much-awaited Li-O2 batteries in electric vehicles and more.

Graphene membrane defects to aid batteries image

The team has developed an in situ technique to induce pores in graphene by doping it with nitrogen during the growth process. Doping the graphene sheet with nitrogen inevitably breaks some carbon bonds in graphene, opening nanoscopic pores. The researchers observed that such pores in doped graphene selectively allow oxygen, leading to oxidation of the underlying copper foil, unlike pristine graphene.

Non-flammable graphene oxide membrane developed for safe mass production

Apr 19, 2017

Researchers at the University of Arkansas have demonstrated a simple and scalable method for turning graphene oxide into a non-flammable and paper-like graphene membrane that can be used in large-scale production. This tackles the issue of high flammability, which has, according to the team, been an obstacle to further development and commercialization.

Using metal ions with three or more positive charges, the researchers bonded graphene-oxide flakes into a transparent membrane. This new form of material is flexible, nontoxic and mechanically strong, in addition to being non-flammable. Further testing of the material suggested that crosslinking, or bonding, using transition metals and rare-earth metals, caused the graphene oxide to possess new semiconducting, magnetic and optical properties.

Updates from Prof. James Tour's graphene lab at Rice University

Apr 09, 2017

Prof. James Tour's research lab in Rice University is one of the leading graphene research groups in the world, with several key technologies first discovered and developed there. Professor Tour is involved with several application areas - from de-icing coating to energy storage and quantum dots production. Prof. Tour was kind enough to share his time and update us on the latest research and commercialization efforts at his lab.

rice university laser process supercapacitor image

The Tour group is now commercializing two of its key technologies. First up is the laser-induced graphene (or LiG), which was reported first in 2014. This is a process in which graphene is formed on a flexible polyimide film using a room-temperature laser-based process. It is possible to pattern this graphene to create devices and as it is formed on a flexible film this easily enables flexible electronics applications.

Manchester U team makes headway in using GO membranes to turn saltwater into drinking water

Apr 05, 2017

Scientists at The University of Manchester have made a breakthrough in the field of graphene oxide membranes for water desalination. Previous research at The University of Manchester found that when immersed in water, graphene oxide membranes become slightly swollen and smaller salts flow through the membrane along with water, but larger ions or molecules are blocked. Now, the team has devised a strategy to avoid the swelling of the membrane when exposed to water. The pore size in the membrane can be precisely controlled which can sieve common salts out of salty water and make it safe to drink.

Manchester U team advances in making GO membranes for water treatment image

When the common salts are dissolved in water, they form a 'shell' of water molecules around the salt molecules. This allows the tiny capillaries of the graphene oxide membranes to block the salt from flowing along with the water. Water molecules are able to pass through the membrane barrier and flow anomalously fast which is ideal for application of these membranes for desalination.

Grafoid unveils GPURE graphene membrane for Li-ion batteries

Mar 15, 2017

Grafoid, the Canadian graphene R&D, investment and technology company, announced the development of its GPURE Graphene Polymer nano-porous membrane intended for next generation Li-Ion battery applications.

The GPURE graphene polymer membrane (GPM) was developed as a chemically inert, freestanding membrane using graphene composites to test ion selectivity using both monovalent and divalent ions. Ion selectivity is a key requirement for a semi permeable membrane in a Li-ion battery structure. By protecting the sensitive electrode materials from unwanted chemical species GPURE GPM diffuses only energy harvesting monovalent ions such as Li+, Na+ etc.