HLB Calculations

[mochiii]

I am unsure how to do this question:

You are using olive oil as oil phase (HLB: 8.6). Span 20 (HLB:8.6) and Tween 20 (HLB:16.7) as emulsifying agents. Total amount of emulsifier mixture is 3.5g. Using HLB system equation, calculate amount of each emulsifier

[studiot]

4 hours ago, mochiii said:

I am unsure how to do this question:

You are using olive oil as oil phase (HLB: 8.6). Span 20 (HLB:8.6) and Tween 20 (HLB:16.7) as emulsifying agents. Total amount of emulsifier mixture is 3.5g. Using HLB system equation, calculate amount of each emulsifier

You need to start by finding the required HLB for the combined emulsifier.

 

Have you done this ?   -    I made it  12.65

[studiot]

2 hours ago, studiot said:

You need to start by finding the required HLB for the combined emulsifier.

 

Have you done this ?   -    I made it  12.65

Sorry I messed up there.

 

The equation you want is

[math]HLB\left( {oil} \right) = \frac{{{W_A}*HLB\left( A \right) + {W_B}*HLB\left( B \right)}}{{{W_A} + {W_B}}}[/math]

Where A refers to the first surfactant and B to the second.

However the values of HLB you quote give the (not) suprising result that you require no tween at all.

Are you sure you posted the correct HLB values ?

 

Trying to look up olive oil values it looks as though your span20 value is too high, you need something below 6

Quote

The studied systems (water-in-oil microemulsions with olive oil) have a requested HLB value around 6-9. The HLB values of the used surfactants ranged between 16,7 to 4,3. The surfactants with an HLB value closer to the requested value are expected to be more suitable foe emulsification.

The span and tween components are supposed to be chosen so their HLB values bracket the oil HLB value.

 

Edited October 29, 2020 by studiot

[studiot]

On 10/29/2020 at 12:57 PM, mochiii said:

I am unsure how to do this question:

Would like to hear how you got on with this one ?