Exam 2: Emulsions

A mixture or disperse system made of two or more immiscible solvents

Emulsion

Examples of Emulsions

Milk
Mayo
Ice Cream
Salad Dressings
Skin Creams
Paint

The dispersed phase/medium (hint: solute)

Internal Phase

The dispersion phase (hint: solvent)

External/Continuous Phase

Mixture with globule size of 0.1 - 10 micrometers

Macroemulsions

Are Macroemulsions thermodynamically unstable or stable

Unstable

Mixture with globule size of 0.01 - 0.1 micrometers

Microemulsions

Are Microemulsions thermodynamically unstable or stable

Stable

o/w

Oil in Water Emulsions

w/o

Water in Oil Emulsions

T/F: Emulsions can also be w/o/w or o/w/o

True

Does o/w have High or Low Viscosity?

Low

Does w/o have High or Low Viscosity?

High

Which emulsion is miscible with water but not with oil?

o/w

Which emulsion is miscible with oil but not with water?

w/o

Which emulsion has colored globules?

o/w

Which emulsion has colorless globules?

w/o

Which emulsion can conduct electricity?

o/w

T/F: Emulsions cannot be sweetened

False

When oil globules reduce in size, the become more readily  ____

Absorbed

Medicinal agents that irritate the skin are less irritating in the ______ of an emulsion

Internal Phase

Emulsifiers (Surfactants) lower the interfacial _____ between two immiscible liquids by forming a monolayer film at the oil-water interface 

Tension

What is a finely divided solids but is still considered an emulsifying agent?

Magnesium Hydroxide

Surfactants has both lipophilic and hydrophilic properties also known as … and is expressed by the Hydrophilic-Lipophilic Balance (HLB) system

Amphiphilic

The following calculates what value?

(MW % of hydrophilic portion of surfactant) / 5

HLB Value

HLB value under 10 is considered (Lipophilic/Hydrophilic)?

Lipophilic

HLB value above 10 is considered (Lipophilic/Hydrophilic)?

Hydrophilic

HLB values can use the ___ method due to its additive properties

Alligation

Each type of oil for an emulsion requires an emulsifier of a particular ____ to make a stable product

Hydrophilic-Lipophilic Balance (HLB)

What are the following preparation methods used to make?

Continental / Dry Gum method

English / Wet Gum method

Forbes Bottle method

Emulsions

What is the ratio of oil, water, and gum for the Gum method?

4:2:1

What emulsifying agent is usually used for the Continental/Dry Gum method?

Acacia

In the Continental/Dry Gum method, what is the emulsifier triturated with?

Oil Phase

In the Continental/Dry Gum method, what is added to the oil phase to make a creamy mixture?

Water

In the English/Wet Gum method, what component that’s 2x the weight of the emulsifer is mixed with it?emulsifier

Water

After mixing the emulsifier in the English/Wet Gum method, what is then added in portions with continuous trituration ?

Oil Phase

What oil characteristics are used for the Bottle Method

Volatile Oils or Oleaginous substances with Low Viscosity

What is the ratio of water and oil in the Bottle Method?

about equal

In the Bottle Method, how is the initial emulsion reach its final volume?

Remaining ingredients