Production of cellulose micro/nanofibrils with sodium silicate: impact on energy consumption, microstructure, crystallinity and stability of suspensions

Abstract

Abstract Pre-treatments reduce energy consumption for the production of cellulose micro/nanofibrils (MFC/CNF). The objective of this work was to study sodium silicate (Na2SiO3) solutions as pre-treatment for Eucalyptus sp. and Pinus sp. pulps. The treatments were identified as EUC SS 5 % and EUC SS 10 % when 5 and 10 % Na2SiO3 were used, respectively. The treatments for Pinus sp. pulp were identified as PIN SS 5 % and PIN SS 10 %, and the untreated pulps as EUC control and PIN control. The lowest hemicellulose content was obtained for PIN SS 10 %. EUC SS 10 % showed the highest WRV values. EUC SS 5 % (∼ 4100 kWh/t) and EUC SS 10 % (∼ 4200 kWh/t) showed the lowest energy consumption. The pre-treated MFC/CNF showed diameters below 45 nm. The lowest viscosity was obtained for EUC SS 5 % (5.5 cP) and the highest for PIN control (7.7 cP), respectively. The zeta potential indicated moderate stability of the suspensions (−24 ∼ −18 mV). Na2SiO3 showed efficiency for MFC/CNF production due to reduced energy consumption and better individualization. The suspensions have compatible characteristics for application as a stabilizer of colloidal systems and reinforcement of composites.