Stokes law

Question 1

High HLB emulsifier used in which phase

Answer 1

water

Question 2

Low HLB emulsifier used in which phase

Answer 2

oil

Question 3

How is emulsifier selected using HLB?

Answer 3

Oil phase components can be given required HLB values.

Required HLB and emulsifier HLB are matched up,

Each oil will have 2 required HLB’s, one for oil-in-wateremulsions, the other for water-in-oil emulsions

Question 4

Compare creaming to sedimentation

Answer 4

creaming dispersed phase settles to top vs sedimentation which settles to bottom of continuous phase

Question 5

Describe Ostwald ripening?

Answer 5

Smaller dispersed particles join to form large crystals

Question 6

Describe flocculation

Answer 6

colloidal particles come out of suspension and form flakes *reversible

Question 7

Describe coalescents

Answer 7

irreversible* process by which two or more droplets merge during contact to form a single daughter droplet.

Question 8

Two types of emulsion formulation

Answer 8

hot method (conversional), cold press

Question 9

Define HLB blends

Answer 9

you can use a 5HLB + 15HLB emulsifiers instead of 10HLB