Introduction: How to Dissolve Cotton
There are many ways that cotton can be dissolved. The method in this video uses Schweizer's Reagent.
Making Schweizer's reagent is simple and you will need a few chemicals:
1. 1.6g Sodium hydroxide
2. 5g Copper (II) sulfate pentahydrate or 3.2g anhydrous
3. 200mL Ammonium hydroxide (29%)
4. Cotton
5. 10% acid solution of HNO3, H2SO4, or HCl
Experiment
First step: Making copper hydroxide
Make a copper hydroxide solution using the 1.6g NaOH and add it to water with 5g copper (II) sulfate pentahydrate dissolved. Copper hydroxide will precipitate. Collect this precipitate by filtration or wait for the precipitate to settle and decant the liquid.
Second step: Making Schweizer's Reagent
Add 200mL of ammonium hydroxide to the copper hydroxide. The solution will become a dark black/blue/purple color. The reagent is now ready.
Third step: Dissolving cotton and reconstitution as rayon
Slowly add about 2g of cotton to the solution and stir until it is fully dissolved. The cotton can then be reconstituted as rayon by introducing the viscous solution to a 10% acid solution of HNO3, H2SO4 or HCl
6 Comments
8 years ago on Introduction
Hello, great instructable :) Is there a difference between copper (I) sulphate and copper (II) sulphate? I'm not sure what I have and would like to try this synthesis (is it called a 'synthesis'? ...new to chemistry).
9 years ago on Introduction
What are some of the other ways that celulose can be dissolved?
9 years ago on Introduction
Very interesting.
9 years ago
I never realised raylon was made from cotton I assume any other source of cellulose would do as well
Reply 9 years ago on Introduction
You are right! Rayon is just a broad term for the reconstituted cellulose. Rayon is typically made from wood, and other sources of cellulose.
9 years ago on Introduction
Copper sulfate can be purchased from some plant stores I think as a fungicide. It can also be purchased online. I just found a link on amazon which sells 10lbs for $30. You definitely don't need that much though. The NaOH can be purchased as well from stores as drain cleaner. You can buy ammonia as a cleaner as well, but i am not sure how concentrated it is. You could concentrate it yourself (not recommended) or using the more dilute version should be fine!