As a natural polymer compound, cellulose has certain defects in physical form and chemical properties, such as poor pyrolysis performance, chemical resistance, and limited strength, thus limiting its application range. From
The micro/nanofilaments separated from natural fibers are composed of bundles of high-strength and high-elasticity cellulose molecular chains. They are a light, environmentally friendly, biodegradable polymer with low density and big
Excellent surface area, high strength, low thermal conductivity and biodegradability have broad application prospects in many important fields such as electronics industry, pharmaceutical industry, advanced materials and packaging.
The preparation method of micro/nanofilaments is also various, but it can be simply divided into chemical method, mechanical method, biological method and the like. Below we mainly talk about the mechanical method.
Preparation of pulp micro/nanofilament by grinding method (preparation of pulp micro/nanofilament using horizontal sander)
The enzymatically prepared pulp was formulated into 1 L of a 1% mass suspension of water and then subjected to a grinding treatment: a disc gap of -10 μm, a grinding speed of 1500 r/min, and a grinding time of 5, 15, 30, 60, 90.
Effect of Cellulase Pretreatment on Micro-morphology of Eucalyptus Pulp Fiber Micro/Nano Fiber
The amount of enzyme is the key factor affecting the degradation of cellulase. The higher the amount of enzyme, the more obvious the effect of cellulase on the fiber, the more the surface of the fiber becomes loose and rough, and the fiber is more suitable under the same grinding conditions.
Easy to separate silk, separate smaller filaments. When the enzymatic hydrolysis time was increased from 2h to 6h, the diameter of the micro/nanofilament obtained by grinding was significantly reduced, but the diameter of the filament did not continue to decrease significantly when the enzymatic hydrolysis time was 8h.
This is because cellulase has a suitable reaction time under specific conditions. When the enzymatic hydrolysis time is 6h, the cellulase may have fully acted on the pulp fiber, the enzymatic hydrolysis time is prolonged, and the pulp fiber morphology and structure are maintained. There will be no significant changes, and the micro/nanofilament diameter will not change significantly.
Effect of grinding time on micro-morphology of eucalyptus pulp fiber micro/nanofilament
As the grinding time is gradually increased, the diameter of the pulp fiber is gradually reduced, and the filament is gradually separated from the fiber. When the grinding time is 60 min, the average diameter of the filament is 420 nm. After the pulp has been ground for 120 minutes,
Most of the filaments have been separated and interwoven in a network, but the filaments are not uniform in diameter and have an average diameter of 128 nm.
Effect of Enzymatic Hydrolysis Conditions on Micro/Nano Filament Diameter of Eucalyptus Pulp Fiber
As the amount of enzyme or the time of enzymatic hydrolysis increases, the diameter of the micro/nanofilament obtained is gradually reduced. This is because the effect of cellulase on the fiber is more obvious as the amount of enzyme or the time of enzymatic hydrolysis increases. solution
The more complete the reaction, the more easily fibrillated the fibers are, and the smaller the micro/nanofilament diameter obtained during the same polishing time.