Flashcards in Emulsion and Suspension Stability (3)Physical Forces that Govern Stability Recap Deck (6)
What particles are subject to Brownian Motion?
Particles less than about 2 microns in diameter, constantly moving due to BM
What factors affect BM / kinetic energy?
Temperature and external forces such as shaking
As particles approach one another what forces do they experience?
Forces of repulsion due to electrostatic interactions (Vr)
Forces of attraction due to VDW forces (Va)
Steric forces if they have a non-ionic surfactant on their surfaces (Energy of steric interactions (hinderance) =Vs
These energies combine to give total overall potential energy
What is the primary minimum?
Permanent aggregation of particles when attraction is maximum and repulsion is minimum
What is the primary maximum?
Repulsive barrier to aggregation when attraction is moderate and repulsion is moderate
Stable suspension / emulsion