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Questions and Answers
How is the HLB value of an amphiphilic molecule calculated?
How is the HLB value of an amphiphilic molecule calculated?
- By multiplying the weight percentage of the hydrophilic part by five
- By dividing the weight percentage of the hydrophilic part by five (correct)
- By subtracting the weight percentage of the lipophilic part from the hydrophilic part
- By adding the weight percentage of the hydrophilic part and the lipophilic part
What does a lower HLB value indicate about a surfactant?
What does a lower HLB value indicate about a surfactant?
- It is a non-ionic surfactant
- It is an anionic surfactant
- It has a hydrophilic character
- It has a lipophilic character (correct)
What type of properties do Tweens, polyoxyethylene derivatives of Spans, have?
What type of properties do Tweens, polyoxyethylene derivatives of Spans, have?
- Lipophilic
- Non-ionic
- Amphiphilic
- Hydrophilic (correct)
What should be the HLB value of an emulsifier to form stable emulsions with an oil phase?
What should be the HLB value of an emulsifier to form stable emulsions with an oil phase?
What are the HLB value ranges for Spans, which are sorbitan esters?
What are the HLB value ranges for Spans, which are sorbitan esters?
Flashcards
HLB value calculation
HLB value calculation
Calculated by dividing the weight percentage of the hydrophilic part by give.
Lower HLB value
Lower HLB value
Indicates the surfactant has a lipophilic (oil-loving) nature.
Properties of Tweens
Properties of Tweens
Hydrophilic properties
HLB value for stable emulsions
HLB value for stable emulsions
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HLB range for Spans
HLB range for Spans
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Tweens HLB Values
Tweens HLB Values
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Spans HLB Values
Spans HLB Values
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Matching HLB Values
Matching HLB Values
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Surface active substances.
Surface active substances.
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Study Notes
HLB Value and Calculation
- The HLB (Hydrophilic-Lipophilic Balance) value is a measure of the balance between hydrophilic and lipophilic parts of amphiphilic molecules.
- The HLB value is calculated by dividing the weight percentage of the hydrophilic part by five, according to Griffin.
- A lower HLB value indicates a lipophilic character, while a higher HLB value indicates a hydrophilic character.
- Griffin has established an empirical scale to determine the HLB values of surfactants, which enables the determination of the optimum range for each surface active substance effect.
Surfactants and HLB Values
- Spans, which are sorbitan esters, have lipophilic properties and low HLB values (1.8-8.6).
- Tweens, which are polyoxyethylene derivatives of spans, are hydrophilic and have high HLB values (9.6-16.7).
Emulsification and HLB Values
- To form stable emulsions, an emulsifier or emulsifier mixture with an HLB value equal to the HLB value of the oil phase should be used.
- Different formulas can be used to calculate the HLB values of surface active substances.
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Description
Test your knowledge of HLB value and calculation with this quiz. Learn about the balance between hydrophilic and lipophilic parts of amphiphilic molecules and understand how to calculate HLB values according to Griffin's empirical scale.
