Re: weird electrostatic effect

[jmclean@chem.ucsd.edu]

William Beaty says:
> Here's a strange thought: I wonder if the electrostatic repulsion effect
> in the 3M factory was caused by a gradient in air pressure.
>
> When tape peels from a spool, the tape becomes charged.  The opposite
> charge is deposited not on the spool, but instead as air ions.  Think
> about it. If you pull ten feet of tape off a spool, the tape is strongly
> charged, but the small spool doesn't become hundreds of times more charged
> than the large tape.  The opposite charge is mostly ions.
>
>
>      + + + + + + + + + + + + + + + + + + + + + + + + + +
>              -    -     -  ---- -- ---  -   -    -
>              -   -   -   - ------ --- -  -  -  -
>             -  --   -  -- ----- ---- ---- - -  -   -
>                  -   - - ---- -- ---   -   -   -
>             -    -   -    - - ---- -  ---  -   -  -
>      + + + + + + + + + + + + + + + + + + + + + + + + + +
>
>    IONIZED AIR IN A CHARGED PLASTIC TUBE BECOMES PRESSURIZED?

My sense is that the ions attracted to the tent area would not increase the
pressure.  They would displace the uncharged molecules, rather than add to
them.  If the pressure were to get higher, then the uncharged molecules
would leave, re-establishing the normal pressure.

-- 
--James McLean
jmclean@chem.ucsd.edu
post doc
UCSD