Unraveling the rapid assembly process of stiff cellulosic fibers from mistletoe berries.

Unraveling the rapid assembly process of stiff cellulosic fibers from mistletoe berries. Biomacromolecules. 2019 Jul 17;: Authors: Horbelt N, Eder M, Bertinetti L, Fratzl P, Harrington MJ Abstract The mucilaginous viscin tissue within mistletoe berries possesses an extraordinary ability to be rapidly processed under ambient conditions into stiff cellulosic fibers (>14 GPa) through simple mechanical drawing. This rapid and extreme transformation process is hydration-dependent and involves an astonishing >200-fold increase in length, providing a relevant role model for efforts to produce advanced composites from cellulose-based structures such as cellulose nanocrystals (CNCs) or cellulose nanofibrils (CNF). Using a combination of in situ polarized light microscopy (PLM), synchrotron X-ray scattering and humidity-controlled mechanical analysis, we examine here the dynamic transition of viscin cell bundle (VCB) from hydrogel-like tissue to high-performance fiber. Our findings indicate a massive phase transition in which cellulose microfibrils (CMFs)1 containing high aspect ratio crystalline domains undergo dramatic reorganization, facilitated by a water-responsive non-cellulosic matrix. Transition from an aligned, yet flowing state to a stiff fiber is likely triggered by rapid water loss below 45% relative humidity (RH). These findings not only help understanding the adaptive success of mistletoe, but may also be relevant for the d...
Source: Biomacromolecules - Category: Biochemistry Authors: Tags: Biomacromolecules Source Type: research