Study Set Content:
Pharmaceuticals
• Gels (creams, particle, precursors)
• Emulsions (creams)
• Aerosols (nasal sprays)
Personal Care Products
• Suspensions (nail polish, face scrubs)
• Solutions/Gels (shampoos, conditioners)
• Foams (shaving cream)
Electronic and Optical Materials
• Liquid crystals (monitor displays)
• Melts (soldering paste)
Change of the shape and the size of a body due to applied
forces (external forces and internal forces).
Deformation
Irreversible deformation
o (matter is not reverted to the original state when the force is
removed)
flow
Reversible deformation
o (matter is reverted to the original form after stress is
removed)
Elasticity
Deformation in term of relative displacement of the particles
composing the body
strain
Measure of internal forces acting within a (deformable) body
stress
Deformation of a body in one direction only
shear
(resulting from the action of a force per unit are
†=shear
stress;
and having a given perpendicular gradient
(y=shear strain).
Classification of Materials According to Types of Flow and
Deformation:
2 Categories
1. Newtonian Systems
2. Non-Newtonian Systems
Was the first to study flow properties of liquids in a
quantitative way.
• Newton
He recognized that the higher the viscosity of a liquid, the greater
is the
force per unit area (shearing stress)
He recognized that the higher the viscosity of a liquid, the greater
is the force per unit area (shearing stress) required to produce a
certain
rate of shear
Is the force per unit area required to bring about flow.
Shearing Stress (F)
Has linear relationship between shear rate and shear stress
Newtonian Flow
Constant viscosity with increasing rate of shear
Newtonian Flow
Ex. Water, ethanol, acetone, glycerine, benzene
Newtonian Flow
Is the difference of velocity (dv) between two planes of liquid
separated by an infinitesimal distance (dr).
Rate of Shear (G) or Velocity Gradient
