Haake mars

Shear stress and apparent viscosity of the protein solution were measured with a dynamic rheometer (HAAKE MARS, Thermo Fisher Scientific, Pittsburgh, PA, USA) equipped with the P60 probe with a gap of 1 mm, and the protein solution was evenly applied to the plate and preserved for 5 min before assays. The parameters were set as follows: the shear rate, temperature, and time were 10 s⁻¹~400 s⁻¹, 25 °C, and 330 s, respectively.
The dynamic rheological properties of proteins solution were measured using a dynamic rheometer (HAAKE MARS, Thermo Fisher Scientific, Pittsburgh, USA) according to the method of Kang et al. [22 (link)]. A 50 mm parallel steel plate geometry with a 0.5 mm gap was used. The raw protein solution was placed between the flat parallel plates with its perimeter coated with a thin layer of silicone oil to prevent dehydration. The sample was heated at a rate of 2 °C/min and continuously sheared in an oscillatory mode at a fixed frequency of 0.1 Hz. The storage modulus (G′) and loss modulus(G″) were recorded continuously from 20 °C to 80 °C.

The hydrolysate viscosities were determined using a modular advanced rheometer system (Haake Mars, Thermo Electron Corp., Germany). The system is equipped with a stainless steel measuring plate (MP 660, 60 mm) and a rotor (PP60H, 60 mm). The temperature was set to 30°C, the frequency was maintained at 1.5 Hz, and the gap between the parallel plates was kept at 1 mm. The hydrolysed samples were measured for 5 min at different shear rates ranging from 50 to 500 s⁻¹.

Rheometric analysis was conducted for CHT-alone (yield value ≈ 0.1670 Pa) and CHT/mPEG blend mixtures (yield value ≈ 0.2406 Pa) to assess the mechanical transitions inherent within the polymeric solution phase. A cone-and-plate Haake MARS (Modular Advanced Rheometer System) rheometer (Thermo Electron Corporation, Karlsruhe, Germany) with cone diameter of 35 mm, cone angle = 1° (sensor C35/1°) Ti, A-factor = 8.905e+04 Pa/Nm, M-factor = 57.01 (1/s)/(rad/s), inertia = 1.721e−06 kg m², damping = 30.00, thermal expansion coefficient: 1.100 µm/°C, compliance = 0.003157 rad/Nm, and a cone/plate gap of 0.51 mm. The temperature was maintained at 20 °C using a MARS II Universal Temperature Controller and a solvent trap was employed to prevent evaporation of the sample. Oscillation frequency sweeps were conducted over a frequency range of 10–0.01 Hz at a constant stress value of 2.0 Pa which was within the linear viscoelastic region of 0.1–7.0 Pa (stress sweep analysis conducted at 0.01 Hz). The variation and behaviour of elastic and loss moduli with reference to increasing frequency (angular frequency—ω) was studied and reported as mechanical characteristics. Further details of the method and equipment settings can be found in author’s previous report published elsewhere^{73 (link)}.