Submicroscopic Structure of Cellulose from Nitrogen r Sorption Measurements

When cotton linters were soaked in cold 10-percent sodium hydroxide, washed, a nd neutralized, and transferred successively to methyl alcohol and benzene, and carefully dried a t reduced pressure, a surface area as high as 71.3 square meters per gram was obtained by the Brunauer , Emmett, T e ller technique. Previous areas for untreated cotton were a ll below 1 sq uare meter per gram. Linters carried t hrough the above steps after soaking in water instead of alkali had an a rea a s h igh as 47.3 square meters per gram . When t he alkalit rea ted sample was condi tio ned in water vapor to 3.3 pe rcent gain in weight, t he surface decreased to 31.6 square mete rs per gram ; fur ther conditioning to an J LO-percent gain in weigh t decreased t he surface to 2.1 square meters per gram. The isot herms of the treated samples s howed strong hysteres is, whereas the isotherms of un t reated cotton showed li t tle or no hysteresis . Calculations of pore s ize distri bution by t he method of Wheeler a nd Shull indicated these materials have rather na rrow distribu tions, t he a lkal itreated materia l havin g a maximum at a pore radius of abo ut 20 Angstroms and the water-soaked materi a l a maximum at about 16 Angstroms.