124. Solving a chemistry problem

129. Compare graphically the viscosity values ​​of the SiO2 hydrosol found experimentally (see table) with those calculated using the Einstein equation. Determine the mass concentration of SiO2 at which structure formation begins. Particle shape factor α = 2.5; the density of SiO2 and water, respectively, is 2.7 g/cm3 and 1 g/cm3, the viscosity of water is 1*10-3 Pa*s.
Volume fraction of the dispersed phase ϕ*102 2 4 6 8 10 12
Viscosity experimental
η *103, Pa*s 1.05 1.11 1.15 1.22 1.46 1.71
Answer: \u003d 19% of the mass.
1. What systems and under what conditions obey the Einstein equation for viscosity?
2. How does the shape of particles of the dispersed phase affect the viscosity of disperse systems?