Impact of agitating speed on viscosity of polyacrylamide solution

Impact of agitating speed on viscosity of polyacrylamide solution: 
During the preparation, the agitating speeds of 200rpm and 600rpm were implemented to examine the viscosities of a series of polyacrylamide solutions at 30°C. It was discovered that solutions with equal concentrations had significant viscosity differences based on the agitation speed during dissolution. Viscosities obtained at higher speeds were only about 60%-70% of those at lower speeds. Therefore, it can be concluded that the higher the speed, the lower the viscosity, and vice versa for polyacrylamide during dissolution.
Effect of agitating speed on viscosity of polyacrylamide solution post-dissolution:
After complete dissolution, the solution was agitated at high speed for an extended period, but no change in viscosity was observed. It appears that the impact of agitation speed on the viscosity of polyacrylamide solution is limited to the dissolution process. Post-dissolution, the intramolecular hydrogen bonds of polyacrylamide and water molecules form an equilibrium state, forming a secondary structure. The activation energy required to disrupt this secondary structure is substantial, and even increasing the agitation speed will not disrupt this structure, thus not affecting the viscosity of the polyacrylamide solution again.