Looks frosty on the roll,
invisible on the job that is how
3M company advertises its product, the
Magic Tape. 3M came up with
transparent cellophane sealing tapes in the thirties. If that was a huge
success, then the
Magic tape introduced in the early
sixties was indeed a roaring
success. The convenience of writing over the Magic Tape with a pen or pencil or marker
increased its popularity
immensely. Today MT has become an integral part of every day life for
everybody - children, adults ,artists,
executives, housewives ……… . 3M soon designed a convenient tape dispenser too. Besides the magic tape 3M has
a whole series of tapes in its
Scotch portfolio, to suit any need/emergency. Particularly impressive are the
colored, patterned and glitter
tapes. The post-it is also currently available in tape form. All
these are tapes which stick onto
a surface when you apply a little
pressure( thumb pressure will do) and hence are also called Pressure SensitiveTapes(PSTs).
But try peeling off the tape,(exclude the post-it ) and you
get a tutorial on magical realism. The tape pulls off a layer of the surface it
is attached to. Amazingly this worked like magic and fetched Andrei Geim and Kostya Novoselov Nobel
Prize in Physics in 2010 for the
discovery of graphene. In
fact the Nobel committee made a mention of the playfulness of the scientists and
their process: Playfulness is one of their hallmarks, one always
learns something in the process and, who knows, you may even hit the jackpot.
Like now when they, with graphene, write themselves into the annals of science. The tape
dispenser used by Geim and Novoselov is currently an exhibit in the Nobel Museum, Stockholm.
But reality remains. Such tapes are
used as short term damage control agents
to hold together heritage
materials or artworks. By the time authorities get down to extensive restoration work, the band-aids are often discolored and/ or are irretrievably
stuck to the surface. Confronted
with this challenge, Professor Baglioni of
the department of Chemistry, University of Florence came up
with a unique solution. He and his
team “addressed the issue from a physicochemical
perspective”.
Professor Baglioni and his team found that the most popular PSTs used for damage control of
artworks are FilmoplatP (FPP),
MagicTape (MT) and ordinary tape(OT). In
all the three the adhesive is acrylic based, while the backing (tape material) was cellulose for FPP, cellulose acetate for MT and polypropylene for OT. The
team had to design a peeling process
restricted to the surface area of the tape so that surrounding areas remained unaffected.
They solubilized a mixture of assorted organic
solvents in water using
a detergent called sodium dodecyl
sulfate . The detergent ensured that the organic solvent mixture remained as
nanosized droplet in the aqueous medium. Hydrogels, which are polymeric scaffolds
with high affinity for water, when
immersed in this medium, absorbed
the same. The swollen hydrogel
was cut into strips of required size
and applied over the tapes. The solvents slowly penetrated the backing and in less than half an hour the tape could be easily pealed off.
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