(high pitched jingling)
(chalkboard writing over
classical strings music)
(hinge creaking)
- Hi there, I'm Lauren.
This is Brain Stuff.
And today's question
is, what is silica gel,
and why do I find little
packets of it in so many things?
I mean that's weird, right?
Why would boots and beef jerky
both come packaged with the same stuff?
Silica, or more precisely silicon dioxide,
is the same stuff that
quartz and sand are made of.
It's a desiccant, meaning that
it adsorbs and holds water vapor.
And yes that's adsorbs
with an ad, not absorbs.
(buzzing)
When we say that
something adsorbs moisture
we mean that water molecules adhere
to the surface of the material.
Think of the way that sand
can seem to soak up water.
The water is really just adhering
to the surface of each grain.
Basically silica gel does the same thing.
It's covered in millions of tiny pores
that can retain moisture
(descending pitch).
It can actually adsorb about 40 percent
of its weight in moisture.
And thus can reduce the relative humidity
in a closed container
down to about 40 percent.
So, you'll find silica
gel packs in anything
that would be affected by excess moisture.
It's in with leather products
where it can limit the growth of mold.
You'll see it packaged with electronics
to reduce condensation.
And because it's nearly harmless,
you'll find it preventing
spoilage in foods like pepperoni.
You still don't want to eat it, though.
If you emptied out a
packet and ate the beads,
they would begin adsorbing moisture
from your tongue, gums,
and the rest of your mouth.
You're first instinct would
probably to be just spit it out.
(spitting)
But if you did swallow it, well.
Okay, probably you'd be fine.
But not all silica gel is the same.
Some of it has a toxic
coating of cobalt chloride.
Swallowing this stuff
probably also won't kill you
but it could cause nausea, vomiting,
and a few other less than
awesome side effects.
But, when it comes to keeping things dry,
silica gel works pretty well.
Which is why it's so wide spread.
It's also find in vitamin
bottles, industrial air systems,
and oddly enough, containers
of cat litter (meowing).
And, this stuff is reusable.
You can dry it out by
heating it in an oven
at about 300 degrees Fahrenheit.
That's about 150 degrees Celsius.
People have found all
sorts of ways to reuse it.
There might be too many to list.
But, I guess I can try.
Okay, here it goes.
Protecting papers from humidity.
Drying flowers.
Preventing rust on tools.
Preventing condensation on windows
and inside picture frames.
Preserving art and display cases.
Mitigating small spills in luggage.
Slowing silver tarnishing.
Stopping seed mold.
Preventing camera lens fogging.
So that should just about
wrap up this question.
But if you guys have any others for us
you can leave them in the
comment section below.
And if you enjoyed it
then please do subscribe,
or come check us out on our
website at brainstuffshow.com.
(high pitched jingling)
