This review treats of the characteristics of morphological and physical surface of wood pulp. The surface area of pulp varies with the pulping yield and the chemical or mechanical treatments, and the value also changes dependent on the measuring method. Liquid permeability method gives a few square meters of specific surface area for the water-swollen pulp, while the very large one is obtained by gas adsorption method or solute exclusion method. The difference in values is interpreted on the basis of the principle of the method.
J. E. Stone and A. M. Scallan have studied using the solute exclusion method the changes in surface area during cooking and refining. They correlated the increase in the surface area on refining with the structural changes, namely the internal fibrillation taking the multi-lamellae structure into account. In addition to their works, interpretation on the structure of cell wall offered by other workers was also described.
