University of Manchester and Khalifa University collaboration uses GO to take salts out of water

A partnership between The University of Manchester and Khalifa University of Science and Technology in Abu Dhabi has yielded graphene-based membranes aimed at to taking salts out of water.

The most popular method for water desalination currently is a process called reverse osmosis, which requires large quantities of water to be forced through a membrane to remove the salts in the water. This method is particularly useful when there is a high salt content, however more efficient methods are required for bodies of water that have a lower salt content, known as brackish water. The team of researchers has developed new ion-selective membranes incorporating graphene oxide, for use in electromembrane desalination processes such as electrodialysis and membrane capacitive deionization.

University of Illinois team finds that defects in graphene membranes may improve biomolecule transport

Researchers at the University of Illinois examined how tiny defects in graphene membranes, formed during fabrication, could be used to improve molecule transport. They found that the defects make a big difference in how molecules move along a membrane surface. Instead of trying to fix these flaws, the team set out to use them to help direct molecules into the membrane pores.

Nanopore membranes have generated interest in biomedical research because they help researchers investigate individual molecules - atom by atom - by pulling them through pores for physical and chemical characterization. This technology could ultimately lead to devices that can quickly sequence DNA, RNA or proteins.

Graphene may be the key to next-gen membranes that filter c02

A way to cut CO2 levels, produced from burning fossil fuels and released into the atmosphere, is through carbon capture, a chemical technique that removes CO2 from emissions ("postcombustion"). The captured CO2 can then be recycled or stored in gas or liquid form, a process known as sequestration.

Graphene helps co2 filtering membranes get more efficient imageCO2-selective polymeric chains anchored on graphene effectively pull CO2 from a flue gas mixture. Credit: KV Agrawal (EPFL)

Carbon capture can be done using high-performance membranes, which are polymer filters that can specifically pick out CO2 from a mix of gases, such as those emitted from a factory's flue. These membranes are environmentally friendly, they don't generate waste, they can intensify chemical processes, and can be used in a decentralized fashion. They are now considered as one of the most energy-efficient routes for reducing CO2 emissions. Now, scientists (led by Kumar Varoon Agrawal) at Ecole Polytechnique Federale de Lausanne (EPFL) have developed a new class of high-performance membranes that exceed post-combustion capture targets by a significant margin. The membranes are based on single-layer graphene with a selective layer thinner than 20 nm, and have highly tunable chemistry, meaning that they can pave the way for next-generation high-performance membranes for several critical separations.

Graphene oxide layers made to mimic biological channels may clean up pharmaceuticals production

KAUST researchers have tailored the structure of graphene-oxide layers to mimic the shape of biological channels, creating ultra-thin membranes to rapidly separate chemical mixtures. This may have the potential to inspire new materials to clean up chemical and pharmaceutical production.

2D-dual-spacing channel membranes for high performance organic solvent nanofiltration image

"In making pharmaceuticals and other chemicals, separating mixtures of organic molecules is an essential and tedious task," says Shaofei Wang, postdoctoral researcher in Suzana Nuñes lab at KAUST. One option to make these chemical separations faster and more efficient is through selectively permeable membranes, which feature tailored nanoscale channels that separate molecules by size.

Chinese researchers achieve photo-induced ultrafast active ion transport through graphene oxide membranes

Researchers from the Chinese Tsinghua University and CAS demonstrated a coupled photon-electron-ion transport phenomenon through graphene oxide membranes. Using the energy of light, cations are able to move thermodynamically uphill over a broad range of concentrations, at rates orders of magnitude faster than that via simple diffusion.

Based on this mechanism, the team further developed photonic ion switches, photonic ion diodes, and photonic ion transistors as the fundamental elements for active ion sieving and artificial photosynthesis on synthetic nanofluidic circuits.