Isolation and Characterization of Cellulose Nanocrystals Created from Recycled Laser Printed Paper

This article presents the development of a method to prepare nanocrystalline cellulose (NCCs) from laser-printed waste paper using factorial design 23 experiments by controlled acid hydrolysis of the waste paper. The method applies high gain ultrasound and subsequent flotation, washing, and bleaching stages. Characterization of the raw material, prepared pulp, test sheets, and NCCs is presented. Optimum conditions to obtain high quality NCCs were found to be 65% acid, for 40 min time of treatment, and residual load in the range of 130 to 570 mmol/kg of NCCs. The obtained NCCs were 80 to 700 nm long depending on the acid hydrolysis conditions. They exhibited high values of whiteness (90.3% Elrepho), -cellulose contents (95%), degree of polymerization (731), viscosity (9.59 cP), and chemical compositions similar to that of Whatman paper.