Lovis 2000 m me

To evaluate particle size distribution in LPs of PTPS, the volumes of lower phases have been increased with PBS up to 1 mL. The dynamic viscosity values were obtained for all tested samples using an automatic microviscometer Lovis 2000 M/ME (Anton Paar GmbH, Ostfildern, Germany) at 298 K. Four measurements followed by averaging were performed for each sample. Dynamic light scattering was performed with a Nanotrac Wave II instrument (Microtrac Inc., Montgomeryville, PA, USA) at 25 °C; the signal accumulation time was 30 s. The results were processed in FLEX Software (Microtrac Inc., Montgomeryville, PA, USA) taking into account the earlier determined values of the suspension viscosity. Each sample was assayed in triplicate, and results were averaged.

The viscosity of the dope solution was determined using a rolling-ball viscometer (Model: Lovis 2000 M/ME, Anton Paar, Ashland, AL, USA). An amount of 100 μL sample solution was taken and put in a capillary tube with a metal ball and the sample viscosity was determined by considering the time taken for the ball to travel through the sample solution in the capillary tube.
The density of the dope solution was determined using a digital density meter (Model: DMA 5000 M, Anton Paar) with an oscillating capillary U-tube. The measurement of density is based on the frequency of oscillation. An amount of 1 mL sample solution is filled into a U-shaped oscillating capillary tube. The density meter is set in connection with the rolling ball viscometer. For the determination of viscosity and density, PC/DCM dope solutions with 3, 6, 9, 12, 15, 17, 19 and 21 wt % polymer concentrations and PC/NMP solutions with 3, 6, 9, 12, 15, 18 wt % polymer concentrations were used. The same sample solutions were also analyzed for the refractive index using a refractometer (RX5000α, Atago, Washington, DC, USA). The refractometer was first calibrated with distilled water of known refractive index. About 2–3 mL of the sample solution was drawn and put in the sample cone of the refractometer.

SV-AUC measurements were carried out with ProteomeLab XL-I (Beckman Coulter, Brea, CA, USA). Samples were filled in 12 mm-pathlength Epon double sector centerpieces. All measurements were performed using Rayleigh interference optics at a 40,000-rpm rotor speed. The time evolution of sedimentation data was analyzed with the Lamm formula. Then, the weight concentration distribution of components, c(s_20,w), was obtained as a function of the sedimentation coefficient. Here, the sedimentation coefficient was normalized to be the value at 20 °C in pure water, s_20,w. The molecular weight M and association number N of each component were calculated using the following equation: $$M={\left[\frac{6\mathsf{\pi }\eta N_{\mathrm{A}}}{\left(1-\rho \overline{v}\right)}\right]}^{1.5}{\left(\frac{3\overline{v}}{4\pi N_{\mathrm{A}}}\right)}^{0.5}{\left(\frac{f}{f_0}\right)}^{1.5}{s}_{20,\mathrm{w}}{}^{1.5} ,$$
$$N=\frac{M}{M_1} ,$$
where $$\rho$$ , $$\eta$$ , $$\overline{v}$$ , $$N_{\mathrm{A}}$$ , $$f/f_0$$ , and $$M_1$$ are the solvent density, solvent viscosity, partial specific volume, Avogadro number, friction ratio, and molecular weight of a monomer, respectively. These calculations were performed with SEDFIT software [33 (link)]. The density and viscosity of solvents were measured with a density meter DMA4500M (Anton Paar, Graz, Austria) and a viscometer Lovis 2000 M/ME (Anton Paar, Graz, Austria), respectively.