| 초록 |
We investigate rheological properties of cellulose nanocrystal (CNC) suspensions dispersed in anionic and neutral polymer solutions. CNCs are rod-like particles and dispersed in hydrophilic matrix well due to their short-range van der Waals attraction. CNC aqueous suspensions show phase transition behavior with increasing particle concentration such as isotropic to nematic phase transition. When CNCs are dispersed in anionic polymer, i.e., carboxymethyl cellulose (CMC) solution, physical gelation and aggregation occur due to polymer adsorptions via ionic strength. However, when CNCs are dispersed in neutral polymer, i.e., polyethylene oxide (PEO) solution, suspensions show different phase transition. Small amplitude oscillatory shear (SAOS) and large amplitude oscillatory shear (LAOS) tests were conducted to characterize microstructural differences by polymer adsorption and ionic strength of polymer matrix. |
