Controlling the Size and Film Strength of Individualized Cellulose Nanofibrils Prepared by Combined Enzymatic Pretreatment and High Pressure Microfluidization

Abstract

The production of functionalized polymers from biomass is of great interest. Cellulose nanofibrils (CNFs) isolated from lignocellulose have great potential in novel functional materials. In the present study, mild enzymatic treatment followed by high pressure microfluidization of a bleached softwood kraft pulp led to the release of individualized CNFs. Disk milling and high pressure microfluidization resulted in entangled networks of CNFs. CNFs from mild enzyme pretreatments were 8 to 12 nm in diameter and 200 to 400 nm in length, while CNFs from pure mechanical pretreatment were an entangled network of nanofibrils with a diameter of 10 to 20 nm. Films prepared from the resulting CNFs were flexible and semitransparent, and they exhibited high specific tensile stress and modulus. The specific tensile stress and modulus were increased by 3-to 5-fold and 5-to 11-fold, respectively. The specific tensile modulus of the CNFs films from mild enzyme treatments followed by microfluidization was approximately 15 to 16 MN·m/kg, while that of CNFs from pure mechanical fibrillation with or without microfluidization was 10 MN·m/kg and 14 MN·m/kg, respectively. The specific tensile strength of the CNFs films from mild enzyme treatment was slightly lower (72 to 98 kN·m/kg) than that of the CNFs films from pure mechanical fibrillation.

Structure and Properties of Polylactic Acid Biocomposite Films Reinforced with Cellulose Nanofibrils

“…CNF was isolated following the protocol developed in our previous studies [ 34 , 37 , 38 ]. Briefly, enzymatic pretreatment of MCC was conducted at 10 wt % MCC loading, 12.8 FPU/g MCC, and 50 °C for 2 h in the acetic buffer (pH 4.6).…”

Kinetic thermal behavior of nanocellulose filled polylactic acid filament for fused filament fabrication 3D printing

“…Nanocellulose was prepared by combined enzymatic pretreatment and high-pressure microfluidization developed in our earlier study. 34 Nanocellulose preparation and characterization are provided in Supporting Information. PEG600 was bought from Sinopharm Chemical Reagent Co., Ltd.…”

“…Molecular weight of PLA is 200 000 ± 5000 g mol −1 provided by the supplier. Nanocellulose was prepared by combined enzymatic pretreatment and high‐pressure microfluidization developed in our earlier study . Nanocellulose preparation and characterization are provided in Supporting Information.…”

A Review on Plant Cellulose Nanofibre-Based Aerogels for Biomedical Applications

“…It is often prepared by the mechanical fibrillation of cellulose and its yield depends on the source of the cellulose and the preparation method. The obtained CNF can include the ultrafine grinding of cellulose biomass or homogenisation and microfluidisation [ 10 ]. In some cases, chemical, enzymatic or even mechanical pre-treatment of CNF is done to enhance the quality of materials, reduce the energy input or achieve other purposes [ 11 ].…”