Triboelectric effect and measuring charge

[pubson]

Hi

 

Im a student who is doing a project which in part requires the use of the triboelectric effect to charge up dust and then look at the effects of this dust when it comes into contact with a low frequency antenna.

 

I didnt study this at school so all I have to go by is the wikipedia page on the subject, my tutor want to measure the polarity and the amount of charge on a rubber balloon when it is rubbed against various materials (eg wool and polyester.) Does anyone here know how to measure the polarity and/or strength of charge on a triboelectrically charged balloon?

 

Also Iv assumed that simply putting the dust or sand into contact with the charged balloon will in turn charge the sand, is this correct?

 

 

Thanks in advance for the help!

[swansont]

If you have a substance with a known charge, you can see if the balloon attracts or repels, and what the force is. Or you could use it to induce a potential difference in a conductor, and measure that.

[YT2095]

an Electroscope may help also, here: http://en.wikipedia.org/wiki/Electroscope

 

and: http://www.mos.org/sln/toe/simpleelectroscope.html

 

another good one instead of tinfoil, goldleaf or pith balls, is too cut out 2 peices from an anti-static bag, the silvery plastic bags that most PC cards and things come in. they work Great

[pubson]

Cheers guys.

 

Also Iv assumed that if I were to simply drop sand or water over a charged balloon that the sand or water would in turn take on some of the charges on the balloon.

 

Meaning to look at the effect of charged sand when it comes into contact with the antenna I simply drop sand over a charged balloon and then onto the antenna.

 

Is my assumption correct?

[YT2095]

why use a "middle man" (the sand) why not use the balloon directly on a plate "antenna" and pick the charge reading up that way?

and if the charge isn`t enough from just that alone, then repeat it several times and store each contribution using a Leyden jar.

[pubson]

Cheers Ill suggest that.

 

Also this has been my main reference as far as the triboelectric effect is concerned.

 

http://en.wikipedia.org/wiki/Triboelectric_effect

 

Iv rubbed a balloon against a cotton t-shirt and then held the balloon against a piece of aluminium foil and the foil stuck. Therefore Id assume that makes the balloon negatively charged right?

 

Would rubbing the balloon with polyester (which is lower down the series) make the balloon positively charged.

 

Im asking as I need to test both positive and negative charges on the antenna.

 

Thanks again in advance.

[swansont]

Iv rubbed a balloon against a cotton t-shirt and then held the balloon against a piece of aluminium foil and the foil stuck. Therefore Id assume that makes the balloon negatively charged right?

 

Why? If the balloon is - then the electrons will move away, and will attract the + charges left. If the balloon is +, it will attract the electrons, and give a force of attraction.

 

A charged insulator should be attracted to a neutral conductor, no matter what the sign of the charge.