Tilted Levitation Solves MagLev Problem

  • Author: Nancy McGuire
  • Published: 26 January 2016
  • Copyright: Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
  • Source / Publisher: Journal of the American Chemical Society/ACS Publications
  • Associated Societies: American Chemical Society (ACS), USA
thumbnail image: Tilted Levitation Solves MagLev Problem

The density of small diamagnetic particles can be measured by suspending them in a paramagnetic solution and applying a magnetic field. Unfortunately, this MagLev method only works in a particle density range close to that of the solution, about 0.8 to 2.3 g/cm3.


George Whitesides and colleagues, Harvard University, Cambridge, MA, USA, found a way around this limitation. They measured the densities of materials from air bubbles to osmium and iridium (23 g/cm3). A typical MagLev device consists of a vertical tube between two magnets with like poles facing each other. Particles suspended in a paramagnetic solution in the tube (aqueous MnCl2 or GdCl3) find a balance point between gravitational and magnetic forces at a height that depends on their density. Very light particles float to the top and very heavy particles sink to the bottom, rendering the technique ineffective.


By tilting the MagLev device, the researchers decreased the buoyant gravitational force along the direction of measurement, enabling them to suspend a wider range of particles without increasing the magnetic field strength. They noted that increasing the range of densities came at the expense of precision in the density measurement.


 

Article Views: 1256

Sign in Area

Please sign in below

Additional Sign In options

Please note that to comment on an article you must be registered and logged in.
Registration is for free, you may already be registered to receive, e.g., the newsletter. When you register on this website, please ensure you view our terms and conditions. All comments are subject to moderation.

Article Comments - To add a comment please sign in

Bookmark and Share

If you would like to reuse any content, in print or online, from ChemistryViews.org, please contact us first for permission. more


CONNECT:

ChemistryViews.org on Facebook

ChemistryViews.org on Twitter ChemistryViews.org on YouTube ChemistryViews.org on LinkedIn Sign up for our free newsletter


A product of ChemPubSoc Europe (16 European Chemical Societies)and Wiley-VCH