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What is the Griffin equation?
- HLB = 20(1-S/A)
- S = saponification # of the ester
- A = acid # of the FA
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What is the Davis equation?
HLB = hydrophilic group number-lipophilic group number +7
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What equation is: HLB = Hydrophilic group number – Lipophilic group number + 7?
The Davis equation
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What equation is: HLB = 20(1-S/A), where S = saponification # of the ester and A = acid number of the FA?
Griffin equation
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Hydrophobic or -philic surfactant have a lower HLB?
Hydrophobic
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A low HLB indicates what property?
Hydrophobicity
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A higher HLB indicates what property?
Hydrophilicity
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A polar surfactant would have a low or high HLB?
High
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A non-polar surfactant would have a high or low HLB?
Low
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A hydrophobic Surfactant would have a high or low HLB?
Low
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A hydrophilic surfactant would have a high or low HLB?
High
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How is the HLB value selected for an emulsion?
By trial and error, until optimal stability is seen
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How many emulsifiers should be used in an emulsion?
One or more, usually a blend works best
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Does a single or multiple emulsifiers work better?
Multiple emulsifiers often work best, but it is dependent on the emulsion
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How is an HLB value determined for combinations of emulsifiers?
By taking the weighted average for individual surfactants
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What type of emulsifier would you select for a W/O emulsions?
Hydrophobic
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What type of emulsifier would you select for an O/W emulsion?
Hydrophilic
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What subgroups are contained in Hydrophilic colloids?
- Natural and Synthetic polymers
- Clays
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Natural and synthetic polymers and clays are what type of emulsifying agents?
Hydrophilic Colloids
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What are specific examples of hydrophilic colloids?
- Acacia (Gum Arabic)
- Tragacanth
- Gelatin
- Algonates
- Bentonite
- Methylcellulose
- Carboxymethylcellulose
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Tragacanth, Methylcellulose, Carboxymethylcellulose, Acacia, Gelatin, Algonites and Bentonite are all what type of emulsifying agent?
Hydrophilic colloids
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