Team finds that an electric field applied to a tiny hole in a graphene membrane could compress water molecules

Researchers at the University of Illinois at Urbana-Champaign have developed new theories regarding the compression of water under a high-gradient electric field. They found that a high electric field applied to a tiny hole in a graphene membrane would compress the water molecules travelling through the pore by 3%. The predicted water compression may eventually prove useful in high-precision filtering of biomolecules for biomedical research.

Compression of water under a high-gradient electric field image

The team commented: "This is an unexpected phenomenon, contrary to what we thought we knew about nanopore transport. It took three years to work out what it was the simulations were showing us. After exploring many potential solutions, the breakthrough came when we realized that we should not assume water is incompressible. Now that we understand what's happening in the computer simulations, we are able to reproduce this phenomenon in theoretical calculations."

Graphene Flagship team uses GO to stretch the limits of gas separation

Researchers associated with the Graphene Flagship have reported overcoming the theoretical limiting performance of membranes in gas separation. This collaborative research from CNR, University of Bologna and Graphene-XT has potential applications in hydrogen purification and carbon capture and storage.

Graphene Flagship team uses graphene to improve gas separation image

The team explains that polymer-based membranes for gas separation have a trade-off between high gas permeability and high gas selectivity, the so-called Robeson upper bound. By combining individual graphene oxide sheets with polymer spacers, in a sandwich style structure, the researchers have been able to overcome this limit, separating gas quickly and efficiently.

MIT team demonstrates a novel method to mass-produce graphene in long rolls

Researchers at MIT have developed a method that might enable the production of long rolls of high-quality graphene. The continuous manufacturing process can reportedly produce five centimeters of high-quality graphene per minute. The longest run was nearly four hours, and it generated around 10 meters of continuous graphene.

MIT's new graphene production method image

MIT is referring to the development as “the first demonstration of an industrial, scalable method for manufacturing high-quality graphene that is tailored for use in membranes that filter a variety of molecules.” These membranes could be used in biological separation or desalination, for example. The researchers drew from the common industrial roll-to-roll approach blended with chemical vapor deposition, a common graphene-fabrication technique.

Surwon Technology to sign filtration products deal

Hong Kong-based advanced materials company Surwon Technology announced that a version of a new membrane coating it has tested in heavy-duty desalination applications could soon be part of new water filtration products specially-developed for the consumer market.

The ultra-thin, graphene-based coating has reportedly continued to perform well in ongoing controlled tests at various desalination plants on the Chinese mainland and the company says it is convinced the technology can make a substantial contribution to reducing the cost of thermal and reverse osmosis systems.

Spanish scientists open the door to using graphene in smart filters and sensors

As part of a national research collaboration, Spanish researchers including the ICN2 have reached a milestone in graphene research, that potentially brings science a step closer to using graphene in filtration and sensing applications.

The researchers have successfully synthesized a graphene membrane with pores whose size, shape and density can be tuned with atomic precision at the nanoscale. Engineering pores at the nanoscale in graphene can change its fundamental properties. It becomes permeable or sieve-like, and this change alone, combined with graphene's intrinsic strength and small dimensions, points to its future use as the most resilient, energy-efficient and selective filter for extremely small substances including greenhouse gases, salts and biomolecules.

XFNANO: Graphene and graphene-like materials since 2009XFNANO: Graphene and graphene-like materials since 2009