2.4 rheological measurement FFS
the rheological properties of FFS were performed on a Haaken Rheostress 6000 rheometer (Thermo Scientific Instrument, Inc. Germany) Fitted with a cone-plate geometry (diameter=25 mm, cone angle =2) with a gap of 0.104 mm. Dynamic oscillatory measurements were carried out in the linear viscoelasticity range(LVR).
storage modulus (G) and the loss modulus (G) were recorded in the 0.1-100 rad/s angular frequency sweep at a strain amplitude of 0.2% (in the LVR). the apparent viscosity as a function of the shear rate was determined in the range from 0.1 to 300s. Sample were individually loaded on the measuring geometry and allowed to stand for 2 min prior to testing. All measurements were performed at 25C and performed in triplicate