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Polymers - PTFE - Poly(tetrefluoroethene) - Teflon - Post-it - Adhesive.
Many
of the materials in common use today
were made by accident.
They were made by scientists who were working on a different project
but had the foresight to notice the
formation of an unexpected product
with
unusual properties. Examples of products which were
made by accident are PTFE and the adhesive for 'Post-it'
labels.
Poly(tetrefluoroethene) or PTFE was
made by a scientist
called Roy Plunkett who was working
for DuPont.
He was looking at materials which were used in fridges called CFCs.
In one of his experiments he noticed that a waxy substance had been
produced which was very slippery and did not
react with other
chemicals.
The material was given the name Teflon
and it was used as the coating for
non-stick
pans for cooking.
Today Teflon has a large number of uses
including bearings, circuit boards, medical
uses and waterproof
clothing.
The adhesive for 'Post-it' labels was
made by a scientist
called Spencer Silver who was working
for 3M.
He was doing experiments with
adhesives (glues) and he was also doing
other experiments, trying out things which would not
have been expected
to produce a strong adhesive, just to see what the result
was.
He produced a glue which does not
form a strong bond
and can easily be removed without
leaving a mark.
The adhesive is made from many tiny balls
called microspheres
which only allow a little of the ball's surface to stick to
things.
It was several years later that someone found a use for the
adhesive.
Post-it
labels have a coating of sticky microspheres
along one side.
The labels are used in offices and
around the home
as a way of temporarily fixing a note to a surface.
The labels can be removed and
replaced many times.
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Copyright © 2008 Dr. Colin France. All Rights Reserved.