microstructure of films obtained by drying the helicoidal Rheologically, suspensions of chitin crystallites are found to phases was characterized using transmission electron mibehave as other molecular liquid crystalline polymers (LCPs). The croscopy (TEM). In this paper, we report on the rheological average hydrodynamic diameter of the crystallites in the suspenproperties of these aqueous chitin crystallite suspensions as sion at pH 4 is determined to be approximately 80 nm using dya function of shear, pH, and concentration.
namic light scattering. Conductimetric and pH titration results
Rheological properties of a suspension are a function of
show that the pK a of the crystallites is 6.3, which is the same as both the shape of the particles and the interparticle forces: that reported for chitosan. In combination with phase diagrams, dispersion and electrostatic repulsive forces. The viscosity flow properties of isotropic, biphasic, and anisotropic chitin suspensions were investigated. For isotropic suspensions, a classical of dilute suspensions of rodlike particles has been treated shear thinning behavior of rodlike particles is observed. In the theoretically for the case of very low shear stress (6). The case of biphasic suspensions, a two-regime curve is observed where theoretical treatment has been confirmed in experiments ustactoids first orient, deform, and then break up under a shearing ing model rod systems such as poly-g-benzyl-L-glutamate force. Similar to other LCPs, a three-regime flow curve is found (PBLG) in m-cresol (7) and dilute suspensions of charged for the anisotropic suspensions. The viscosity-concentration curve cellulose microfibril fragments (8). Hermans (7) reported exhibits a maximum at the phase separation concentration, and that the viscosity of PBLG in m-cresol reached a maximum this maximum is less distinct with a decrease of the ionic strength.
at the concentration where the phase transition of isotropic Secondary electroviscous effects due to strong particle-particle to anisotropic occurred. This was confirmed by Kiss and interactions influence the viscosity of the suspensions at higher Porter for the same polymer (9). Similar observations were concentrations.