imported>Stwikiadmin at 17:08, 4 November 2016

2016-11-04T17:08:03Z

← Older revision		Revision as of 17:08, 4 November 2016
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	{\| class="wikitable" style="color:black; background-color:#ddd; margin-left: auto; float:right"		{\| class="wikitable" style="color:black; background-color:#ddd; margin-left: auto; float:right"
	\| [[Chemistry]]:		\|[[Chemistry]]:
	\| Polymers, Hydrophilic ~~& Hydrophobic~~		\|Polymers,
			Hydrophilic Molecules
	\|-		\|-
	\| Grade Range:		\|Grade Range:
	\| [[Elementary School]], [[Middle School]], [[High School]]		\|[[Elementary School]],
			[[Middle School]], [[High School]]
	\|-		\|-
	\| Format:		\|Format:
	\| [[Stage]]		\|[[Stage]]
	\|}		\|}

imported>Stwikiadmin at 15:03, 17 May 2016

2016-05-17T15:03:49Z

← Older revision		Revision as of 15:03, 17 May 2016
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	* Salt		* Salt
	* Scissors		* Scissors
	* Gallon Zip-lock Bag		* 1 Gallon Zip-lock Bag
	* Glass Cups or Beakers		* Glass Cups or Beakers
	* Water		* Water
			* Spoon

	== Safety Precautions ==		== Safety Precautions ==
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	== Demonstration ==		== Demonstration ==

	~~'''''WRITEUP IN PROGRESS'''''~~		# Take a Diaper and start cutting it open on the inside to reveal the absorbent pad. Carefully pull out the pad and put it inside of a 1 gallon zip-lock bag.
	# ~~Steps~~ for the ~~demonstration~~.		# Close the bag, leaving air inside of it, and start shaking it. Explain to the audience that the absorbent pad in a diaper works because of the tiny acrylic acid crystals that are added to it. After shaking it for a minute, open the bag and toss the pad. there will be a collection of crystals in the bottom of the zip-lock bag!
	# ~~Be sure~~ to ~~clarify on steps about any safety equipment needed~~.		# Dump the crystals from the bag into a cup or beaker, and add about 4 oz (~120 ml) to it. Stir it, and let it sit for a minute or two so the crystals can absorb the water. While it is sitting, explain the difference between hydrophobic and hydrophilic.
	# ~~Make sure steps~~ can be ~~understood by~~ a ~~first-time reader~~.		# Once the water has been absorbed, pick up the glass and hold it upside down over your head. The mixture stays inside the glass! If the mixture looks like it has air pockets, you can even add another ounce (~30 ml) of water to it.
			# Now add a spoonful of salt to the solution and stir it thoroughly. As you stir, the solution will become wet again, and the crystals stop sticking to each other! This final solution can safely be poured down a drain.


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	===Short Explanation===		===Short Explanation===
	This ~~is where you would provide a basic~~, ~~easy~~-to-~~understand explanation of the demonstration~~. ~~Try~~ not to ~~use too~~ much ~~"Science Jargon"~~, and ~~if needed~~ add ~~any explanation tips~~, ~~like comparing~~ the ~~demo~~ to ~~something kids are familiar with~~.		Diapers are very absorbent because of the unique polymer that they use in them. ''Polymers'' are molecules of the same type that like to connect to each other, like plastics, and they will usually stretch and bend to stay connected. Most plastic polymers don't absorb water, and instead repel it. This means that they are ''Hydrophobic'', or "water-fearing". However, the crystals that are in the diaper pad like to absorb water. These crystals are acrylic acid, and when dry they don't connect to each other. However, the crystals are ''Hydrophilic'', or "water-loving". This means that they not only absorb water, but they will try to absorb as much as 300 times their mass! As they absorb water, the crystals start to stick together, becoming a polymer gel, and even sticking to the inside of the glass as well! When we add the salt, it breaks the connections between the crystals, and destroys the polymer. Although the crystals will still hold some water in them, the salt forces them to lose a lot of it, which makes the solution liquid again.

	===Full Explanation===		===Full Explanation===
	This is ~~where you will explain~~ the ~~demonstration in full~~, ~~and provide all additional information~~ that ~~pertains~~ to the ~~demo~~. ~~Unlike the short explanation above~~, ~~this should be worded so someone who~~ is ~~familiar with the topics might understand~~ it. ~~If needed~~, ~~you can provide equations~~ and ~~citations for additional sources~~ of ~~information on~~ the ~~topic~~. ~~This~~ is ~~also where you will find some answers for trickier questions~~, ~~such as "How does~~ a ~~plane fly upside-down?" for~~ the ~~Bernoulli~~'~~s Principle demo~~. ~~If you want~~ to ~~add~~ a ~~floating box for equations~~, ~~copy~~ the ~~following:~~		A diaper needs to be able to absorb liquid without leaking. This task is done by the use of ''Polymers'', identical molecules that connect to each other end to end. The polymers that we are all most familiar with are plastics, and the majority of plastics are hydrophobic. ''Hydrophobic'' materials are ones that, when water is poured or spilled on them, repel water and don't absorb any of it. This is because, on the molecular level, the bonds between the molecules are close enough and strong enough to prevent water from passing through them. The outer layer of a diaper is made of plastic because of this, so that the diaper won't leak onto an unsuspecting parent or caregiver.

			The pad inside of a diaper is highly absorbent. Part of the absorption is because of the type of pad, but a large amount of the absorption is because of what is added to the pad. Diaper pads have crystallized ''Sodium Polyacrylate'', a ''Polyacrylic Acid'' salt, added into them. These crystals are tiny, and when dry they don't look like much. However, these crystals become quite amazing once they are wet. Polyacrylic acid becomes a polymer when wet, causing the crystals throughout the diaper to start linking together. Polyacrylic acid is also ''Hydrophilic'', a material that readily absorbs water and will expand several times its size to try to absorb more of it. In this case, the crystals will expand to absorb up to 300 times their mass in water!

	{\| class="wikitable" style="color:black; background-color:#ddd; text-align: center; margin: auto"		{\| class="wikitable" style="color:black; background-color:#ddd; text-align: center; margin: auto"
	\| ~~This will give you~~		\| Sodium Polyacrylate (Anhydrate)
	\| ~~a floating box.~~		\| Polyacrylic Acid (Hydrated)
	\|-		\|-
	\| ~~The box will be~~		\| [C<sub>3</sub>H<sub>3</sub>NaO<sub>2</sub>]<sub>n</sub>
	\| ~~centered for you.~~		\| [C<sub>3</sub>H<sub>3</sub>O<sub>2</sub><sup>-</sup> + Na<sup>+</sup>]<sub>n</sub> + N H<sub>2</sub>O
	\|}		\|}

			When the sodium polyacrylate is in water, the sodium separates from the polyacrylic acid. Polyacrylic acid doesn't dissolve in water solutions, however, and it will start connecting with the other polyacrylic acid moelcules. Even though each of them have a net negative charge, they bond together because the negative charge is isolated to one of the oxygens, which allows the carbons to bond with each other by passing a hydrogen up to the oxygen. This makes polyacrylic acid an '' Anionic Polyelectrolyte'', a chemical that becomes a polymer when it loses one of the positive charges in solution. The water molecules become encased in the polymer, since it can only form while the sodium is dissolved in the water, and the polymer will actively absorb as much water as possible in order to better contain the sodium ion. This is why the polymer will absorb as much as 300 times its mass in water!

			When we add the salt to the solution, we are flooding the solution with excess sodium. The extra sodium starts to bond with the polyacrylic acid, which breaks the polymer and causes it to fall apart. The crystals will still hold onto water, but the salt increases the molar mass of the solution, which causes the crystals to lose some of it. This results in the crystal gel falling apart and "melting" back into solution. This final solution is safe to pour down a drain because of the added salt as well; The leaking crystals have some of the salt trapped inside of them now, so their ability to absorb water is compromised.
	== Additional Information ==		== Additional Information ==

	* Any extra tidbits that do not fit into other sections		* This demonstration pairs well with the [[Polymer Milk Jug]] and the [[Vanishing Peanuts]].
	* This demonstration ~~is a part of~~ the ~~(insert~~ [[~~Stage Show~~]] ~~here)~~		* Let students know that this can be easily done at home!

imported>Stwikiadmin: Created page with "{| class="wikitable" style="color:black; background-color:#ddd; margin-left: auto; float:right" | Chemistry: | Polymers, Hydrophilic & Hydrophobic |- | Grade Range: | [[Eleme..."

2016-05-16T21:13:23Z

Created page with "{| class="wikitable" style="color:black; background-color:#ddd; margin-left: auto; float:right" | Chemistry: | Polymers, Hydrophilic & Hydrophobic |- | Grade Range: | [[Eleme..."

New page

{| class="wikitable" style="color:black; background-color:#ddd; margin-left: auto; float:right"
| [[Chemistry]]:
| Polymers, Hydrophilic & Hydrophobic
|-
| Grade Range:
| [[Elementary School]], [[Middle School]], [[High School]]
|-
| Format:
| [[Stage]]
|}

This demonstration is one that students could easily replicate at home. Be sure the salt is mixed thoroughly before trying to dump it, otherwise it won't go down the drain.

== Materials ==

* Diapers
* Salt
* Scissors
* Gallon Zip-lock Bag
* Glass Cups or Beakers
* Water

== Safety Precautions ==

Please read the Dry Chemical section of the [[Demonstration Safety]] page before performing this demonstration.

This demonstration requires: Safety Glasses

== Demonstration ==

'''''WRITEUP IN PROGRESS'''''
# Steps for the demonstration.
# Be sure to clarify on steps about any safety equipment needed.
# Make sure steps can be understood by a first-time reader.

== Why This Works ==

===Short Explanation===
This is where you would provide a basic, easy-to-understand explanation of the demonstration. Try not to use too much "Science Jargon", and if needed add any explanation tips, like comparing the demo to something kids are familiar with.

===Full Explanation===
This is where you will explain the demonstration in full, and provide all additional information that pertains to the demo. Unlike the short explanation above, this should be worded so someone who is familiar with the topics might understand it. If needed, you can provide equations and citations for additional sources of information on the topic. This is also where you will find some answers for trickier questions, such as "How does a plane fly upside-down?" for the Bernoulli's Principle demo. If you want to add a floating box for equations, copy the following:

{| class="wikitable" style="color:black; background-color:#ddd; text-align: center; margin: auto"
| This will give you
| a floating box.
|-
| The box will be
| centered for you.
|}

== Additional Information ==

* Any extra tidbits that do not fit into other sections
* This demonstration is a part of the (insert [[Stage Show]] here)

Diaper Polymers - Revision history

imported>Stwikiadmin at 17:08, 4 November 2016

imported>Stwikiadmin at 15:03, 17 May 2016

imported>Stwikiadmin: Created page with "{| class="wikitable" style="color:black; background-color:#ddd; margin-left: auto; float:right" | Chemistry: | Polymers, Hydrophilic & Hydrophobic |- | Grade Range: | [[Eleme..."