| 초록 |
This study reports a straightforward approach to fabricate microbial cellulose nanofibrils (MCNFs), which have significant potential for rheology modification of complex fluids. The MCNFs with controlled amounts of hydrophobic alkyl groups on their surface are fabricated by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation in the aqueous solution. Induction of controlled electrostatic interaction of MCFs with polyethylenimine results in formation of a nanofibrillar crystalline gel phase. Furthermore, the MCNF gel network with the controlled inter-fibril hydrophobic association displays reversible shear thinning in response to applied shear stress. From rheological studies, finally, we demonstrate that the MCNFs exhibit not only strong viscosity enhancement, but also reversible sol-gel transition. |
