Rheology Flashcards
What is viscosity?
Measurement of resistance to flow
What is Newtonian flow?
An ideal liquid that flows under pressure
What are Bingham Bodies?
No flow until a minimum amount of stress is reached
What are some examples of bingham bodies?
Concentrated suspensions
pastes) and emulsions (mayonnaise
What are Pseudoplastics?
Flow rate (rate of shear) increases with increased shearing stress
What are some examples of pseudoplastics?
Polymer solutions, colloids, ketchup, whipped cream, blood
What are Dilatants?
Flow rate (rate of shear) decreases with increased shearing stress
What are some examples of dilatants?
Suspensions, corn starch solution (oobleck)
What are Thixotropics?
- Close to pseudoplastic (shear thinning)
- Time-dependent viscosity:
- Viscosity decreases the longer a certain shear stress is applied for
What are some examples of thixotropics?
Ophthalmic, vaginal gels
How do you calculate viscosity?
Viscosity of H20 x ((Density of ? x Runoff of ?/(Density of H20 x Runoff of H20))
