Rheological properties were measured using an AR-G2 rotational rheometer (TA, America) equipped with a parallel plate
(20 mm diameter). A sample suspension (20 g/100 mL) was loaded
on the rheometer and silicon oil was applied to the exposed edge to
prevent evaporation loss. The gap size and strain were set at 1 mm
and 2%, respectively. Samples were heated from 25 to 95 C and
then cooled down to 25 C at a rate of 5 C/min at the frequency of
1 Hz. Then frequency was swept from 0.1 to 20 Hz at 25 C. Data