TESTING THE WATERPROOF ABILITY OF HOUSEHOLD SUBSTANCES
Madi P 2013
Cary Academy
ABSTRACT
These experiments were done to test the waterproof ability of household substances. The sunscreen
substance contains Benzoophenones, Oxybenzone, Dioxybenzone, and Avobenzone. The substances were
applied to a sheet of plexiglass and sprayed with water, using a light probe to test how waterproof the
substance was. Sharpie pen proved to be the most waterproof.
INTRODUCTION
Hydrophilic molecules are molecules that have a strong affinity for water. These molecules cling to the water
molecules. The opposite of Hydrophilic molecules are hydrophobic molecules, which repel water. The name
“hydrophobic” literally means “water fearing”. The prefix “hydro” means “water”. “Philic” means “having an
affinity for; loving” and “phobic” means fearing. Common hydrophobic molecules are those of fats, oils,
steroids, ipids, and aromatic compounds (such as some drugs). An amphiphiles molecule is one that has both
hydrophobic and hydrophilic domains.
Sunscreen is used a lot during the summer. What people may not know is that sunscreen contains ingredients
such as Cinnamates, OMC (Octyl Methoxycinnamate), Ethylhexyl p-Methoxycinnamate, Salicylates, OCS (Octyl
Salicytate), Homomenthyl salicylate, Triethanolamine, PABA (Para Aminobenzoic Acid), Padimate O, Padimate
A, Glyceryl Aminobenzoate, Octocrylene, Octyl Dimethyl Paba, Zinc Oxide, and Titanium Oxide. The ingredients
in sunscreen used to absorb UVA rays and radiation are Benzoophenones, Oxybenzone, Dioxybenzone, and
Avobenzone. Zinc Oxide is one of the main and most well-known ingredients in the sunscreen.
Painting the nails on the fingers is great fun, but it’s all got to come off at some time. To remove nail polish,
nail polish remover is usually applied to the nail with a cotton ball or Q-Tip. Nail polish is very handy, but what
some may not know is it’s made out of acetone, ethyl acetate or butyl acetate, and alcohol. These ingredients
help loosen and remove the polish from the nail. There are many different types of nail polish remover on the
market currently, but those are the base ingredients used in pretty much each one. These ingredients are
reported to make skin and nail dry and/or brittle. To counter, some nail polish removers include castor oil,
cetyl palmitate, or lanolin in the list of ingredients.
Michelle Schwartz did a study on the durability of lipstick brands. She found that Bobbi Brown lipstick is the
most durable. The lipstick was applied to cling wrap then the measure of light that shone through was
recorded. Bobbi Brown let through about 900 lux of light, Clinique let through about 1400 lux of light, and
Maybelline let through about 1000 lux of light.
MATERIALS AND METHODS
The materials used in these experiments were waterproof sunscreen, nail polish, foot cream, sharpie
pen, a spray bottle, nail polish remover, a light probe, a flashlight, water, an online stopwatch, plexiglass, and
a computer.
The sheet of plexiglass was laid out. Sunscreen was applied to the plexiglass and let dry for two minutes. A
light probe then recorded how much light shone through. Water was sprayed onto the sunscreen using a
spray bottle. A light probe recorded how much light shone through. The sunscreen was sprayed with water
again, and the amount of light that shone through was recorded. The sunscreen was sprayed with water one
last time and the amount of light that shone through was recorded.
Figure 1: Diagram explaining the method used to complete this experiment
Sharpie pen was rubbed onto the sheet of plexiglass, and dried for two minutes. The amount of light that
shone through was recorded using a light probe. The sharpie was sprayed with water using a spray bottle. The
amount of light that shone through was recorded again. The sharpie was sprayed with water again and the
amount of light that shone through the sharpie was recorded. The sharpie was then sprayed with water one
last time. The amount of light that shone through was recorded using a light probe.
The sheet of plexiglass was laid out and foot cream was applied to it. The foot cream was left to dry for two
minutes. How much light shone through was recorded using a light probe. The foot cream was then sprayed
with water using the spray bottle. The amount of light shining through the foot cream was recorded. The foot
cream was again sprayed with water. The amount of light that shone through the foot cream was recorded
using a light probe. The foot cream was sprayed with water using the spray bottle one more time and the
amount of light that shone through was recorded
The plexiglass had nail polish applied to it. The nail polish sat to dry for two minutes. A light probe then
recorded how much light shone through. Water was sprayed onto the nail polish using a spray bottle. A light
probe recorded how much light shone through. The nail polish was sprayed with water again, and the amount
of light that shone through was recorded. The nail polish was sprayed with water one last time and the
amount of light that shone through was recorded.
Nail polish was applied to the plexiglass. The nail polish sat to dry for two minutes. A light probe then recorded
how much light shone through. Nail polish remover was sprayed onto the nail polish using a spray bottle. A
light probe recorded how much light shone through. The nail polish was sprayed with nail polish again, and
the amount of light that shone through was recorded. The nail polish was sprayed with nail polish remover
one last time and the amount of light that shone through was recorded.
RESULTS AND DISCUSSION
Figure 2: Graph comparing the differences of each substance
This graph shows the results of all the substances. Most ingredients showed next to no change over the period
of sprays. Sunscreen is the most affected, as it ran down the plexiglass as soon as it was sprayed with water.
The foot cream also washed off a lot. The water will lift of the hydrophilic molecules (molecules that stick to
the water molecules). The sunscreen was actually waterproof, but still proved the most hydrophilic molecules.
50
45
40
Difference (lux)
35
30
25
20
15
10
5
0
0
0.5
1
1.5
2
2.5
3
Sprays
Figure 3: Graph showing the data of the Sharpie Substance
This graph shows the results for the Sharpie substance. As it shows, the sharpie never washed much off the
board. This makes sense, because the molecules of the sharpie cling to the surface they are placed on. The
molecules of the sharpie are hydropholic. This is why if one was to get some of an article of clothing, it doesn’t
wash off easily. It would be best to use more than water to get sharpie off a surface.
70
60
Difference (lux)
50
40
30
20
10
0
0
0.5
1
1.5
2
Spray
Figure 4: Graph showing the results of the Foot Cream substance
2.5
3
3.5
This graph is for the substance Foot Cream. It was not affected very much when sprayed with water. This
makes sense because the cream was oily, which was necessary for it to be moisturizing like it was made to be.
The oil molecules are hydrophobic. Although it was a hydrophobic substance, there seemed to be more
hydrophilic molecules. This overpowered the hydrophobic molecules and the substance was mostly washed
off.
16
14
12
Difference (lux)
10
8
6
4
2
0
0
0.5
1
1.5
2
2.5
3
3.5
Sprays
Figure 5: Graph showing the data from the Nail Polish experiment
This is the graph for the Nail Polish substance. It showed that it did run off a little, but not as much as some of
the other substances. This makes sense because nail polish is oily and oil repels water due to its hydrophobic
molecules. Nail polish remover is used to remove nail polish, water is not.
1000
900
800
Difference (lux)
700
600
500
400
300
200
100
0
0
0.5
1
1.5
2
Sprays
Figure 6: Sunscreen
2.5
3
3.5
This graph shows the results of the sunscreen substance. This sunscreen was waterproof and washed off
easily. This, however, does not make much sense. Waterproof sunscreen is supposed to be oily, as to repel
water. Oils are a hydrophobic, meaning the molecules repel water. The waterproof sunscreen proved to have
hydrophilic molecules, meaning it’s molecules cling onto molecules and are washed away easily. It dripped
down the plexiglass on the first spray.
10
9
8
Difference (lux)
7
6
5
4
3
2
1
0
0
0.5
1
1.5
Sprays
2
2.5
3
3.5
Figure 7: Graph showing the results of the Nail Polish remover experiment
In this experiment, it showed that the nail polish came off a lot more when sprayed with nail polish remover. This makes
sense since nail polish remover is created to remove nail polish. On the third spray it started to run down the board.
CONCLUSION
In conclusion, the sharpie proved the most waterproof. In the beginning it was thought the sharpie would be,
but it turned out the water washed it off a little. This data is important to show to the world not only for
scientific purposes but so others know which substance to use if they want to have something waterproof.
Follow up experiments include testing how much light shines through nail polish when sprayed with vinegar,
olive oil, or Windex.
CITATIONS
"Acetone." Medical and Cosmetic uses n.pag. Wikipedia. Web. <http://en.wikipedia.org/wiki/Acetone>
"Choosing the Best Sunscreen." n.pag. Sunscreen Ingredients. Web. 20 Feb 2013.
<http://www.sunscreeningredients.com/>.
Levy, Joel . Waterproof Clothing. Singapore: Firefly Books, Print.
"Hydrophobic Effect." n.pag. Wikipedia. Web. <http://en.wikipedia.org/wiki/Hydrophobic_effect>.
Morgan, Nina, O.E. Clark, and D'Argenio David. Chemistry Keywords. New York: Oxford University Press, 2003.
Print
Shwartz, Michelle. “Durability of Lipstick Brands.” Cary Academy; 2012
"What is Nail Polish Remover?." n.pag. wiseGEEK. Web. 20 Feb 2013. <http://www.wisegeek.org/what-is-nailpolish-remover.htm>.