How do you dissolve cellulose

5.1.1 Dissolving cellulose in s reagent

Material / chemicals:

  • Cotton wool
  • Cu (OH)2(harmful to health)
  • NH3 conc. (25%) (corrosive)
  • least. water


  • 2 beakers (400 ml)
  • spatula

Experimental setup:

Execution of the experiment:

  1. 3 g of cotton wool are placed in 100 ml of water
  2. 2 g Cu (OH)2 are dissolved in 105 mL ammonia. The result is a deep blue solution that s reagent.

3 g of cotton wool are added to Schweizer's reagent and the mixture is stirred until the cellulose has dissolved.


A. The cellulose shows no visible change.
B. The cellulose dissolves. A deep blue, clear solution is created.


  1. The cellulose is insoluble in water because the cellulose chains are strongly connected by hydrogen bridges.

    The long cellulose chains combine to form crystal-like structures that water cannot dissolve. The water molecules penetrate between the cellulose chains - the cellulose swells - but do not bring them into solution.

  2. In Schweizer's reagent, the cellulose dissolves as a copper-cellulose complex. The Cu present in the solution2+-Ions with ammonia initially form the deep blue colored copper tetrammine complex [Cu (NH3)4]2+. At a high pH value, this reacts with the cellulose and breaks the hydrogen bonds between the cellulose chains.

    The crystal-like structures are broken down and water molecules can loosen the complexed cellulose chains.

Disposal information:

The copper cellulose solution and its residues are disposed of in the heavy metal waste.


  • All devices that have come into contact with the copper cellulose solution are cleaned with diluted ammonia before rinsing with water, as otherwise insoluble cellulose residues can form.
  • The experiment should be carried out near the table fume cupboard, as the ammonia odor that arises can be very unpleasant.

Video clip:

You can watch the demo video here:

5.2.2 Production of a regenerated cellulose film using the copper silk process

© 2001Markus Förg, [email protected]