LG and researchers at ETH Zürich announce graphene membrane breakthrough

As reported by Solid State Technology : "Researchers from LG Electronics (LG) and Swiss university ETH Zurich (Swiss Federal Institute of Technology Zurich) have developed a method to greatly increase the speed and efficient transmission of gas, liquid and water vapor through perforated graphene, a material that has seen an explosion of scientific interest in recent years. The findings open up the possibility in the future to develop highly efficient filters to treat air and water. [...]  developed a reliable method for creating 2D membranes using chemical vapor deposition (CVD) optimized to grow graphene with minimal defects and cracks to form graphene layers thinner than 1nm (nanometer). Using a focused ion beam (FIB), the researchers then drilled nanopores in double layers of graphene to produce porous membranes with aperture diameters between less than 10nm and 1µm (micrometer). Testing various sized perforations, the researchers found that their graphene membrane resulted in water permeance five- to sevenfold faster than conventional filtration membranes and transmission of water vapor several hundred times higher compared to today’s most advanced breathable textiles such as Gore-Tex."

 

 

The full report by Kemal Celebi et al can be read in Science publication below:

 

Ultimate Permeation across Atomically Thin Porous Graphene

Kemal Celebi, Jakob Buchheim, Roman M. Wyss, Amirhossein Droudian, Patrick Gasser, Ivan Shorubalko, Jeong-Il Kye, Changho Lee, Hyung Gyu Park

Science 18 April 2014: Vol. 344 no. 6181 pp. 289-292,  DOI: 10.1126/science.1249097                        

A two-dimensional (2D) porous layer can make an ideal membrane for separation of chemical mixtures because its infinitesimal thickness promises ultimate permeation. Graphene—with great mechanical strength, chemical stability, and inherent impermeability—offers a unique 2D system with which to realize this membrane and study the mass transport, if perforated precisely. We report highly efficient mass transfer across physically perforated double-layer graphene, having up to a few million pores with narrowly distributed diameters between less than 10 nanometers and 1 micrometer. The measured transport rates are in agreement with predictions of 2D transport theories. Attributed to its atomic thicknesses, these porous graphene membranes show permeances of gas, liquid, and water vapor far in excess of those shown by finite-thickness membranes, highlighting the ultimate permeation these 2D membranes can provide.