How to Make Color-Changing Thermochromic Slime

Updated on May 20, 2018
leahlefler profile image

After having obtained a degree in biochemistry, Leah works for a small biotechnology company and enjoys writing about science.

This Slime Changes Color!

This slime used a black/pink color changing pigment and would shift color at 88F (31C).
This slime used a black/pink color changing pigment and would shift color at 88F (31C). | Source

Simple STEM Activity with Thermochromic Pigment

Creating a slime that changes color with temperature is an easy STEM project for the home or classroom. The addition of heat-sensitive pigments (thermochromic pigments) causes the color of the slime to shift at a specific temperature. Depending on the thermochromic pigment added, the color may shift at different temperatures. Pigments that shift at 88°F (31°C) or 77°C (25°C) are recommended for this project, as some pigments require temperatures above 90°F (32°C) to shift. It is difficult to obtain the higher temperatures in a classroom setting.

Mixing the Thermochromic Pigment Powder

Thermochromic pigment powder is extremely light and will spread easily. Take care when mixing it into the glue base used for slime!
Thermochromic pigment powder is extremely light and will spread easily. Take care when mixing it into the glue base used for slime! | Source

Materials Required to Make Color Changing Slime with Borax

  1. 1 oz. white school glue (about ¼ bottle)
  2. 3 tablespoons of water
  3. ¼ teaspoon borax mixed into 2 tablespoons of water.
  4. 3 teaspoons thermochromic pigment
  5. Food coloring (optional, useful for thermochromic pigments that shift to a colorless state)

Materials Required to Make Color Changing Slime without Borax

  1. 1 oz. white school glue (about ¼ bottle)
  2. 1/8 teaspoon baking soda
  3. 3 teaspoons thermochromic pigment
  4. Bottle of saline-based contact lens solution
  5. Food coloring (optional, useful for thermochromic pigments that shift to a colorless state)

Low Temperature Color Changing Pigment

Low Temperature Cold Activated Thermochromic Bi-Color Pigment Pink Changing to Black at 64F/18C Perfect for Color Changing Slime Silly Putty Goo
Low Temperature Cold Activated Thermochromic Bi-Color Pigment Pink Changing to Black at 64F/18C Perfect for Color Changing Slime Silly Putty Goo

This pigment will change color from black to pink at 64F/18C, which is perfect for classroom activities.

 

Instructions for Mixing Thermochromic Slime

Before mixing the slime ingredients, verify the activity of the thermochromic pigment. Heat or cool the pigment to the temperature at which it shifts, verifying the pigment is active prior to using it in the recipe.

If using food coloring for slimes which transform to a colorless state, make sure your color is the opposite of the pigment color. If a red food coloring is used with a red pigment, you will not be able to see the shift when the slime becomes colorless. For a red pigment, select a yellow food coloring that will not overwhelm the pigment in the recipe.

Thermochromic pigment is supplied in a powder form. Take care when using the powder as it spreads easily and may stain. Do not expose the thermochromic powder to sunlight for an extended period of time, as this may degrade the molecular structure of the pigment and cause it to lose its color-shifting capabilities.

For the recipe including borax, the instructions are:

  1. Add 1 oz. white glue to a mixing bowl.
  2. Add 3 tablespoons of water to the mixing bowl and stir.
  3. If desired, add a few drops of food coloring.
  4. Add 3 teaspoons of thermochromic pigment to the mixing bowl and stir to combine.
  5. Mix the 1/4 teaspoon borax with 2 tablespoons of water in a separate bowl or cup.
  6. Add the borax solution to the glue/pigment solution and stir until it begins to combine.
  7. Knead the slime until it becomes cohesive and is no longer sticky.

For the recipe without borax, the instructions are:

  1. Add 1 oz. white glue to a mixing bowl.
  2. Add 1/8 teaspoon baking soda tothe mixing bowl and stir.
  3. If desired, add a few drops of food coloring.
  4. Add 3 teaspoons of thermochromic pigment to the mixing bowl and stir to combine.
  5. Add 1 teaspoon of contact lens solution and stir until it begins to combine.
  6. Knead the slime until it becomes cohesive and is no longer sticky. If the slime remains sticky, add contact lens solution until it is smooth and does not stick to your hands.

The Color is Dependent on Temperature

On a hot day, the pink/black thermochromic slime will turn a pink color. When the temperature cools, it will shift back to black. Experiment with friction, body heat, and ice cubes to change the color of the slime!
On a hot day, the pink/black thermochromic slime will turn a pink color. When the temperature cools, it will shift back to black. Experiment with friction, body heat, and ice cubes to change the color of the slime! | Source

Change the Color of the Slime!

Once the slime is completed, get your slime to change color by applying heat. On a hot day, the slimes which change color at 77°C (25°C) will be in the shifted state. Using an ice cube will cause the color to shift to the original state. The pigments that shift at 88°F (31°C) will require a heat source to shift unless the day is very warm. Try placing the slime on a hot playground slide or on a cookie sheet heated by the sun! Friction will also cause the slime to change color, so rolling some of the slime in your hands will cause it to shift. The color change is reversible, so you can continually heat and cool the material to watch the color change many times.

Source

Why Does the Slime Change Color with Heat?

Thermochromic pigments contain a molecular structure that changes at a specific temperature, which alters the wavelengths of light it reflects. For the black changing to pink pigment, the pigment will absorb all light wavelengths until it reaches 88°F (31°C). At the higher temperature, the molecular structure shifts and absorbs all wavelengths but red/pink, which is the longest wavelength on the visible color spectrum. The reflected red/pink color is what our eyes observe when this shift happens. A pigment that shifts from blue to colorless goes from reflecting only the blue wavelength to reflecting all of the wavelengths.

The capabilities of thermochromic pigments are used for simple thermometers. Another application of thermochromic pigments is in heat-sensitive paper, which allows receipts to be printed without the use of ink.

Change the Color of Thermochromic Slime Using Ice

Other Applications of Thermochromic Pigment

Heat sensitive pigment may be used in other projects, such as

  • Color-changing playdough. Use your favorite playdough recipe and add thermochromic pigment after the cooking stage for color changing fun!
  • Thermocolor Paint. Use a transparent gloss medium as a base and add the thermochromic pigment. Combine thoroughly and use the paint on a mug to watch a color transformation when hot liquid is added.
  • Color changing thermometer. Create thermocolor paints from pigments that shift at different temperatures. Paint a strip of each thermocolor paint on a white surface and label each one with the temperature where the color-shift occurs. Place the thermometer in a location that does not receive direct sunlight and observe the outdoor temperature by which pigments have changed color!

Questions & Answers

  • Is it ok to handle the pigment frequently in the slime?

    The pigment is safe to handle, but should not be heated above the recommended maximum temperature in the instructions for use (this was well above 200 degrees Fahrenheit for the pigment used in the slime manufactured for this article). As with all homemade slime, care should be taken to wash hands after use as borax can be a skin irritant.

Comments

    0 of 8192 characters used
    Post Comment

    • leahlefler profile imageAUTHOR

      Leah Lefler 

      6 months ago from Western New York

      Adria, you are correct! I corrected the error (thank you for pointing that out)! I also added a wavelength chart to the article.

    • profile image

      Adrià 

      6 months ago

      I liked the experiment but red wavelenght is the largest, not the smallest i think

    • leahlefler profile imageAUTHOR

      Leah Lefler 

      7 months ago from Western New York

      Hi Shawna, I made one batch with about six kids in my Maker Camp. We divided up the slime into zip lock baggies for them to take home. It could be divided among 10 kids per batch (with each child taking home a smaller amount), so I would at least increase the recipe by 10. You will only need one container of thermochromic pigment - it goes a long way. I used 3 teaspoons from my container and it appeared there was enough left to make another 10 batches. You will need considerably more glue and borax, but fortunately glue is the inexpensive part of slime!

    • profile image

      Shawna 

      7 months ago

      How much slime does this make? I would like to do this with about 100 students and I'm trying to figure out how much to buy.

    • leahlefler profile imageAUTHOR

      Leah Lefler 

      10 months ago from Western New York

      It is extremely fun to make, Shane. We have had a lot of fun making color-changing slime and experimenting with using different thermochromic pigments to create a slime thermometer! Let me know how your experiment goes!

    • profile image

      shane 

      10 months ago

      this project is so awesome i am totaly doing this for my stem fair project.

    • leahlefler profile imageAUTHOR

      Leah Lefler 

      13 months ago from Western New York

      Thank you for the offer, Eva - I don't do reviews for payment from a company or receipt of product, but your thermochromic pigment does work extremely well. A little goes a long way - I am donating some pigment to our school so they can perform a few science experiments in their new STEM project area.

    • profile image

      Eva 

      13 months ago

      Leah,

      Thank you so much for sharing your experience with our Color Changing Thermochromic Pigment. We're so happy you like it. If you leave us a 5 Stars Product Review on Amazon, we would love to mail you another 10 grams Thermochromic Pigment for FREE. It applies to all your readers too. We love our customers.

      Eva

      Atlanta Chemical Engineering LLC

    • leahlefler profile imageAUTHOR

      Leah Lefler 

      16 months ago from Western New York

      It is a great deal of fun, Karen! I recently did this recipe with our local Maker Camp and the kids really enjoyed it. They would put it on the warm playground slides to cause the color to shift to pink, then use ice cubes to "draw" on the slime to change it back to black. They had a great time!

    • Karen Hellier profile image

      Karen Hellier 

      16 months ago from Georgia

      Such a wonderful and very detailed hub. I wish I had this recipe when I was doing home daycare!

    • leahlefler profile imageAUTHOR

      Leah Lefler 

      16 months ago from Western New York

      I didn't have anything like this as a child, either, Peggy! I love exploring science with kids, and I hope it inspires them to pursue careers in one of the STEM fields!

    • profile image

      Peggy Woods 

      16 months ago

      What a fun project for kids! We did not have anything like that when I was a child. I have to admit it was a long time ago! Haha!

    • leahlefler profile imageAUTHOR

      Leah Lefler 

      16 months ago from Western New York

      It is one of the best slime recipes we have done so far, S Maree! I have found the borax slime has the best consistency, but the contact lens version also works well. The viscosity is about the same for both formulations. The thermochromic pigments can be obtained online - there are different versions available. Some change from one color to another color, while others change from one color to clear (colorless).

    • profile image

      S Maree 

      16 months ago

      Jee-mi-nee! Why didn't we have such cool experiments in school?

      Can you show us how the different formulas behave? Is the viscosity the same? This enquiring mind wants to know!

      How are the thermochromic pigments obtained? You've got this geezer's attention! Good work!

    working

    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, wehavekids.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://wehavekids.com/privacy-policy#gdpr

    Show Details
    Necessary
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
    Features
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Marketing
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Statistics
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)