In the Classroom

Science Discipline:

Chemistry; cosmetic chemistry

Topics:

  • States of Matter
  • Chemical reactions
  • Acids/ Bases

Activity title:

How To Make Your Own Hair Gel

Materials:

  • Carbomer 940
  • Triethanolamine
  • Colored hair spray
  • Small plastic sample cups with lids
  • Popsicle sticks
  • Stir bar
  • Spatula
  • Plastic pipets
  • 1/2 teaspoon measuring spoon

Solution A

  • Carbomer 940 (20 g)
  • Water (3.91 L)

Solution B

  • Triethanolamine (28 mL)
  • Water (40 mL)

Procedure:

Prep should be done a day before

Prep:

  1. The day before both solutions A and B should be prepared.
  2. Solution A is made by mixing the Carbomer 940 with the water using a stir bar and spatula.
  3. Solution B is made by mixing the Triethanolamine with the water.

Hair Gel:

  1. The student will be provided with a sample cup and popsicle stick for stirring.
  2. 1 teaspoon of solution A will be placed in students sample cup.
  3. 1 drop of solution B is then added
  4. The student will then stir the solution until gel consistency is achieved.
  5. Students are able to style their hair and add color using colored hair spray.

Questions:

This scientific experiment allows students to put into practice what is being learned in the classroom and they begin to ask question

  1. What would happen if more Carbomer is added? What role does Carbomer play in the reaction?
  2. What would happen if more Triethanolamine is added? What role does Triethanolamine play in the reaction?
  3. How could you determine the pH of both the acid and base in the reaction?
  4. What state of matter do the compounds start off as? What state of matter is the product?
  5. What are the consequences of adding equal amounts of Carbomer and Triethanolamine?
  6. Would the reaction be affected if more water was added to solutions A and B? If less water was added?

Explanation:

In this experiment, hair gel will be made. Hair gel is a clear styling agent. It is an intermediate between a solid and a liquid. Gel will dry in the hair and stiffen to hold any hair style of choice. Carbomer is an acrylic polymer used as a cosmetic thickening agent. It becomes acidic when mixed with water but then neutralized with the Triethanolamine. This causes cross-linking with the polymer creating the gel.

Next Generation Science Standards: www.nextgenscience.org

PK-Grade 3:

At this level of education, students understand all matter is made up of tiny particles called atoms. They know the difference between the different physical states and properties of liquid, solid and gas. Students begin to ask questions and perform investigations. From experimentation they know when two substances are mixed together a new substance is formed with new properties. In addition to mixing of substances, they know evaporation and melting are changes a substance undergoes through heating. Students begin to form predictions of outcomes based on observation and understand scientist don’t rely on conclusions unless backed up by confirmed observations.

In this experiment, we will be making our own hair gel. Students will be able to identify the acid, Carbomer 940, and base, Triethanolamine, as liquids. Liquid is a state of matter that can flow and change in shape. They can begin to make predictions as to what will happen by mixing the two liquids. When mixing and stirring the two liquids, students will see a new substance formed. Students will learn hair gel is an intermediate between a liquid and a solid.

Grade 4-6:

At this level of education, students know atoms combine to form molecules. The students become familiar with the periodic table and how it is arranged. They know each element on the periodic table is made of one atom and the elements are arranged by chemical properties. Students are able to distinguish between physical and chemical properties of substances and know these criteria are used to identify compounds and separate mixtures. In addition, students know about chemical reactions and how the atoms on the reactant side are rearranged forming products with different properties.

In this experiment, we will be making our own hair gel. The students will be able to identify that both the Carbomer 940 and the Triethanolamine are liquids. Carbomer 940 is a polymer which is made of many monomers. Both monomers and polymers are made up of molecules which are made up of elements. This correlates with the student’s knowledge of elements from the periodic table. They begin to conceptualize how one atom forms an element, elements form molecules, molecules together form monomers, and many monomers form a polymer. Triethanolamine is the base used in the experiment and is composed of elements to form a compound. The students will be able to identify these elements. During the experiment the atoms of the reactants are rearranged thus forming a new product. By mixing and stirring the two liquids the product formed is an intermediate between a liquid and solid, a gel.

Middle school:

At this level of education, students know the atom is composed of protons, neutrons, and electrons. They know by combining two or more different elements they form a compound. The compounds now have different properties from their constituent elements. Students are more familiar with chemical reactions and understand they usually release or absorb heat. They know whether a solution is acidic, basic or neutral. In addition, students understand chemistry has a vital role in the functions of the biological system. Students begin to make a connection between the different kinds of molecules like proteins and fats and how they play a role in living organisms.

In this experiment, we will be making our own hair gel. Hair gel is an acid-base chemistry reaction. Carbomer 940 is an acid and Triethanolamine is a base. Acids are proton donors and bases are proton acceptors. Therefore, in this reaction there is a transfer of protons. Acids can be neutralized with the addition of a base. The use of the Triethanolamine neutralizes the polymer, Carbomer 940. This neutralization causes a cross-linking in the polymer creating the gel. Students will be able to mix and stir this acid and base until these two liquids reach a gel consistency.