Effects of Pretreatment on the Dispersibility of Bamboo Pulp Fiber Suspensions for Nanocellulose Preparation

Abstract

Industrial production efficiency of nanocellulose by mechanical homogenization was directly affected by dispersibility of pulp suspensions. The bamboo pulp was pretreated by oxidation using 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), enzymatic hydrolysis, and refining to study dispersibility of the pulp suspensions. Physical morphology and surface charges of the pretreated pulp fibers were analyzed to explain the differences of dispersibility. Multiple light scattering results showed that TEMPO oxidized pulp fibers and refined pulp fibers had good dispersivity, while the pulp fibers treated with cellulase hydrolysis exhibited comparatively lower dispersibility. The TEMPO oxidized pulp fibers had high carboxylate contents and high absolute value of Zeta potential. The dispersibility of the fibers could be improved by dispersants, and the maximum dispersion of fibers from enzymatic hydrolysis was obtained with 0.5% carboxymethylcellulose as dispersant.