There are several chemicals which can dissolve cellulose fibers,some are so expensive and some can dissolve partially. Therefore, what is your goal from dissolving cellulose fibers? Is there any industrial goals or only research goal?
Some ionic liquids (they can also have acidic or basic character) are good solvent for cellulosic materials, but they are quite expensive and lead to partial depolymerization of polysaccharide chain, but the depolymerizing activity is not so strong like for common acids and bases used to cellulose pretretment http://pubs.acs.org/doi/pdf/10.1021/cr9001947
As said, There are several chemicals which can dissolve cellulose fibers. They are divided to three main groups:
1. Organic solvents: such as Dimethylacetamide (in the presence of LiCl as Catalyst); mixture of Dimethyl sulfoxide/SO2/Triethylamine; and N-Methylmorpholine Oxide
2. Aqueous solvents: such as concentrated Sodium Hydroxide solution; concentrated Sulphuric Acid; Cuam; Cuen; Cadoxen (which are so expensive)
3. Ionic liquids: such as [Bmim]Cl (1-Butyl-3-methylimidazolium chloride); Dimethylformamide; CS2 (Xanthic acid)
Some are used to produce cellulose derivatives and some are used to dissolve cellulose. Be careful so much, some are so toxic. on your goal, you can choose one of them. It is recommended to use Sodium Hydroxide or Sulphuric Acid.