High-Consistency Mechano-Enzymatic Fibrillation of Bamboo Pulp Fibers to Produce Precursors for Highly Fibrillated Cellulose and Dense Films with Multifunctionalities

High-consistency mechano-enzymaticfibrillation (HCMEF) is a greenapproach to producing high solid fibrillated cellulose (HSFC), inwhich most micro- and nanoscale fibrils can be generated. Here, theHCMEF approach was proposed to pre-fibrillate bleached- and lignin-containingpulp fibers to yield coarse HSFC as precursors that were further refinedby microfluidization or phosphorylation combined with microfluidizationto produce highly fibrillated cellulose with multifunctionalities.The results showed that microfluidization alone of HSFC could significantlyreduce fibril diameter and narrow size distribution and considerablyenhance mechanical and barrier properties of the resulting films.The post-phosphorylation followed by microfluidization generated fibrilswith the highest fibrillation degree; the cast films possessed intrinsicflame-retardance and excellent oxygen barrier properties in additionto greatly improved tensile strength (up to 180 MPa). In addition,the resulting highly fibrillated lignin-containing cellulose filmsexhibited excellent UV-shielding performance, blocking as high as99% UV lights while retaining moderate optical transparency (62% at600 nm). High solid fibrillated cellulosegenerated by a high-consistencymechano-enzymatic fibrillation approach is an ideal precursor forhighly fibrillated cellulose production.