Magnetic Anisotropy of Cellulosic Materials

Abstract

The results of a survey of the magnetic anisotropy of a group of cellulosic materials measured according to the Krishnan "oscillation" method are presented. The technique is described for the application of this method to the measurement of the anisotropy of fibrous materials. Experimentally it was found necessary to subject the samples to brief pretreatment with cold, dilute acid in order to obtain concordant results for a given material. Data are given to show the effect on the observed anisotropy of variations in this pretreatment. The results of magnetic anisotropy measurements are discussed as to their possible usefulness in characterizing molecular orientation. It is shown that for materials of a given crystalline modification (cellulose I or II) the observed anisotropy is primarily a function of molecular orientation, but that the anisotropy varies with orientation in a different manner for the two crystalline modifications. The influence of variations in the amount of crystalline material on the observed anisotropy is also briefly discussed.