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Separation of Fullerenes by Electrophoresis

IP.com Disclosure Number: IPCOM000104808D
Original Publication Date: 1993-Jun-01
Included in the Prior Art Database: 2005-Mar-19
Document File: 2 page(s) / 68K

Publishing Venue

IBM

Related People

Gambino, RJ: AUTHOR [+2]

Abstract

Disclosed is a way to separate high molecular weight carbon clusters, commonly known as buckyballs, buckyrods or fullerenes, by electrophoresis. Their molecular weights typically vary between 60 and 1000 atomic mass units. Fullerenes have unique electrical, optical and magnetic properties depending on their shape and molecular weight. Solvent extraction and chromatography can be used to extract a mixture of C sub 60 and C sub 70 from carbon soot, but is not effective in separating the higher molecular weights where mass differences are smaller.

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Separation of Fullerenes by Electrophoresis

      Disclosed  is a way to separate high molecular weight carbon
clusters, commonly   known  as  buckyballs,  buckyrods  or
fullerenes, by  electrophoresis.   Their  molecular  weights
typically  vary  between 60  and  1000  atomic  mass  units.
Fullerenes have  unique  electrical,  optical  and  magnetic
properties depending on  their shape  and  molecular weight.  Solvent
extraction and chromatography  can  be  used  to extract a mixture of
C sub 60  and  C sub 70 from  carbon soot, but is  not  effective  in
separating  the higher molecular weights where mass differences are
smaller.

      The  fullerenes are closed surfaces composed of both 6- and
5-member carbon rings.  The complexing agent, ethylene diamine (EDA),
preferentially attaches to sites on the more reactive 5-member rings
and develops a positive charge.  Therefore, the total charge   Q   is
proportional to the number of 5-member  rings.  The ratio  of
5-member to  6-member  rings generally decreases, and the effective
radius increases with molecular weight.  Therefore, the ratio  Q/R
decreases with increasing molecular  weight and is  different for
rod and sphere shapes (Fig. 1).  Ionic mobility in electrophoresis is
proportional  to     Q/R     or  (electric  field force)/drag
allowing separation based on  both shape and molecular weight.

      The apparatus is shown in Fig. 2.  A 0.2 molar solution of EDA
serves both as complexing agent and electrolyte . A strip of filter
paper  supported  on a  glass  slide ...