Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Thinnest feasible membrane produced

Artist’s rendering of the two-layered graphene membrane (grey honeycomb structure) with molecules (blue) being able – as a function of their size – to pass the pores.Illustration: Ben Newton / ETH Zurich
Artist’s rendering of the two-layered graphene membrane (grey honeycomb structure) with molecules (blue) being able – as a function of their size – to pass the pores.

Illustration: Ben Newton / ETH Zurich

Abstract:
Researchers have produced a stable porous membrane that is thinner than a nanometre. This is a 100,000 times thinner than the diameter of a human hair. The membrane consists of two layers of the much exalted "super material" graphene, a two-dimensional film made of carbon atoms, on which the team of researchers, led by Professor Hyung Gyu Park at the Department of Mechanical and Process Engineering at ETH Zurich, etched tiny pores of a precisely defined size.

Thinnest feasible membrane produced

Zurich, Switzerland | Posted on April 17th, 2014

The membrane can thus permeate tiny molecules. Larger molecules or particles, on the other hand, can pass only slowly or not at all. "With a thickness of just two carbon atoms, this is the thinnest porous membrane that is technologically possible to make," says PhD student Jakob Buchheim, one of the two lead authors of the study, which was conducted by ETH-Zurich researchers in collaboration with scientists from Empa and a research laboratory of LG Electronics. The study has just been published in journal Science.

The ultra-thin graphene membrane may one day be used for a range of different purposes, including waterproof clothing. "Our membrane is not only very light and flexible, but it is also a thousand fold more breathable than Goretex," says Kemal Celebi, a postdoc in Park's laboratory and also one of the lead authors of the study. The membrane could also potentially be used to separate gaseous mixtures into their constituent parts or to filter impurities from fluids. The researchers were able to demonstrate for the first time that graphene membranes could be suitable for water filtration. The researchers also see a potential use for the membrane in devices used for the accurate measurement of gas and fluid flow rates that are crucial to unveiling the physics around mass transfer at nanoscales and separation of chemical mixtures.

Breakthrough in nanofabrication

The researchers not only succeeded in producing the starting material, a double-layer graphene film with a high level of purity, but they also mastered a technique called focused ion beam milling to etch pores into the graphene film. In this process, which is also used in the production of semiconductors, a beam of helium or gallium ions is controlled with a high level of precision in order to etch away material. The researchers were able to etch pores of a specified number and size into the graphene with unprecedented precision. This process, which could easily take days to complete, took only a few hours in the current work. "This is a breakthrough that enables the nanofabrication of the porous graphene membranes," explains Ivan Shorubalko, a scientist at Empa that also contributed to the study.

In order to achieve this level of precision, the researchers had to work with double-layer graphene. "It wouldn't have been possible for this method to create such a membrane with only one layer because graphene in practice isn't perfect," says Park. The material can exhibit certain irregularities in the honeycomb structure of the carbon atoms. Now and again, individual atoms are missing from the structure, which not only impairs the stability of the material but also makes it impossible to etch a high-precision pore onto such a defect. The researchers solved this problem by laying two graphene layers on top of each other. The probability of two defects settling directly above one another is extremely low, explains Park.

Fastest possible filtration

A key advantage of the tiny dimensions is that the thinner a membrane, the lower its permeation resistance. The lower the resistance, the higher the energy-efficiency of the filtration process. "With such atomically thin membranes we can reach maximal permeation for a membrane of a given pore size and we believe that they allow the fastest feasible rate of permeation," says Celebi. However, before these applications are ready for use on an industrial scale or for the production of functional waterproof clothing, the manufacturing process needs to be further developed. To investigate the fundamental science, the researchers worked with tiny pieces of membrane with a surface area of less than one hundredth of a square millimetre. Objectives from now on will be to produce larger membrane surfaces and impose various filtering mechanisms.

####

About ETH Zurich
ETH Zurich is one of the leading international universities for technology and the natural sciences. It is well-known for its excellent education, ground-breaking fundamental research and for implementing its results directly into practice.

Founded in 1855, ETH Zurich today has more than 18,000 students from over 110 countries, including 3,900 doctoral students. To researchers, it offers an inspiring working environment, to students, a comprehensive education.

Twenty-one Nobel Laureates have studied, taught or conducted research at ETH Zurich, underlining the excellent reputation of the university.

For more information, please click here

Contacts:
Hyung Gyu Park

41-446-329-460

Copyright © ETH Zurich

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Literature reference

Related News Press

News and information

Hybrid nanoantennas -- next-generation platform for ultradense data recording April 28th, 2016

Superfast light source made from artificial atom April 28th, 2016

Arrowhead Pharmaceuticals Files for Regulatory Clearance to Begin Phase 1/2 Study of ARC-521 April 28th, 2016

The Translational Research Center at the University Hospital of Erlangen in Germany uses the ZetaView from Particle Metrix to quantify extracellular vesicles such as exosomes April 28th, 2016

JPK reports on the use of a NanoWizard AFM system at the University of Kaiserslautern to study the interaction of bacteria with microstructured surfaces April 28th, 2016

Physics

Superfast light source made from artificial atom April 28th, 2016

Physicists detect the enigmatic spin momentum of light April 26th, 2016

Rare Earth atoms see the light: Physicist Dirk Bouwmeester discovers a promising route for combined optical and solid state-based quantum information processing April 25th, 2016

The atom without properties April 22nd, 2016

Graphene/ Graphite

University of Illinois researchers create 1-step graphene patterning method April 27th, 2016

Atomic magnets using hydrogen and graphene April 27th, 2016

Chemistry

Adding some salt to the recipe for energy storage materials: Researchers use common table salt as growth template April 22nd, 2016

NRL reveals novel uniform coating process of p-ALD April 21st, 2016

Team builds first quantum cascade laser on silicon: Eliminates the need for an external light source for mid-infrared silicon photonic devices or photonic circuits April 21st, 2016

Discoveries

Superfast light source made from artificial atom April 28th, 2016

The Translational Research Center at the University Hospital of Erlangen in Germany uses the ZetaView from Particle Metrix to quantify extracellular vesicles such as exosomes April 28th, 2016

NREL theory establishes a path to high-performance 2-D semiconductor devices April 27th, 2016

Atomic magnets using hydrogen and graphene April 27th, 2016

Materials/Metamaterials

Hybrid nanoantennas -- next-generation platform for ultradense data recording April 28th, 2016

University of Illinois researchers create 1-step graphene patterning method April 27th, 2016

NREL finds nanotube semiconductors well-suited for PV systems April 27th, 2016

Atomic magnets using hydrogen and graphene April 27th, 2016

Announcements

Hybrid nanoantennas -- next-generation platform for ultradense data recording April 28th, 2016

Superfast light source made from artificial atom April 28th, 2016

Arrowhead Pharmaceuticals Files for Regulatory Clearance to Begin Phase 1/2 Study of ARC-521 April 28th, 2016

The Translational Research Center at the University Hospital of Erlangen in Germany uses the ZetaView from Particle Metrix to quantify extracellular vesicles such as exosomes April 28th, 2016

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Hybrid nanoantennas -- next-generation platform for ultradense data recording April 28th, 2016

Superfast light source made from artificial atom April 28th, 2016

The Translational Research Center at the University Hospital of Erlangen in Germany uses the ZetaView from Particle Metrix to quantify extracellular vesicles such as exosomes April 28th, 2016

Researchers create artificial protein to control assembly of buckyballs April 27th, 2016

Water

Novel anti-biofilm nano coating developed at Ben-Gurion U.: Offers significant anti-adhesive potential for a variety of medical and industrial applications April 25th, 2016

Adding some salt to the recipe for energy storage materials: Researchers use common table salt as growth template April 22nd, 2016

NRL reveals novel uniform coating process of p-ALD April 21st, 2016

Researchers create perfect nanoscrolls from graphene’s imperfect form April 14th, 2016

Textiles/Clothing

The impact of anti-odor clothing on the environment March 31st, 2016

No more washing: Nano-enhanced textiles clean themselves with light: New technique to grow nanostructures that degrade organic matter when exposed to light March 23rd, 2016

Stretchable electronics that quadruple in length March 4th, 2016

Replacement of Toxic Antibacterial Agents Possible by Biocompatible Polymeric Nanocomposites February 12th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic