[pharaoh123]

Thanks for responding. I should have been more clear with my question I think.  If you mix glycerine with water, like soap or something of that nature, it lowers the surface tension of the water, that's why soap works for dishes right? I guess what I meant to ask is how long will the glycerin affect the properties of water? Is the lowered surface tension a permanent change until one were to add new water?

[Borek]

it lowers the surface tension of the water, that's why soap works for dishes right?

Google micellae.

[pharaoh123]

I googled micellae; so does that mean the water molecules would be permanently affected by the glycerine?

[Borek]

In a way yes, but what I was referring to is the fact that soap works by creating micellae with hydrophobic substances inside. This way they can be 'dissolved'.

[P]

In a way yes, but what I was referring to is the fact that soap works by creating micellae with hydrophobic substances inside. This way they can be 'dissolved'.

Quite right  -  the dirt gets encapsulated in the micelles (emulsified even!?)  The soap molecules have a Hydrophobic and an hydrophilic end to them (water disliking and water liking ends) The hydrophobic parts attach to the dirt and 'crowd' round it leaving the hydrophilic ends stuck out in the water.

As for surface tension reduction - part of this is because on the surface of the water you get a film of the soap building up  -   the hydrophilic ends stay in the water and the hydrophobic chains 'stick out' of the surface, actively breaking the surface skin of the water up a bit and thus lowering the surface tension. The soap molecules acting in this way are said to be 'surface active ingredients' because they act at the surface and thus the soaps are called ' surfactants'. (SURFice ACTive ingrediANTS)

[pharaoh123]

Great information. Thank you very much.  One last thing I think. Any idea how many parts per million (hundred, thousand, etc) of glycerin to water it takes to have the desired surface tension/breaking effect?

[P]

Great information. Thank you very much.  One last thing I think. Any idea how many parts per million (hundred, thousand, etc) of glycerin to water it takes to have the desired surface tension/breaking effect?

"the desired effect"   Hmmm   -  How long is a piece of string?    The surface tension of water is a mmeasuredthing- thus quantised! (Units are Dynes I think but can't be bothered to look it up right now).   Now, if you add a little surfactant - the surface tension will be reduced by X Dynes.  If you add more then it will be reduced by X Dynes and some more Dynes.   It al ldependson what yyou're'desired effect' is.   

Regards.   

[pharaoh123]

Thanks again for the help. The reason I ask this is I'm wondering what the necessary application to a pond of around 3 million gallons would be. Would there be organisms in the pond that I'd need to consider that may eat the glycerine?  Obviously there would be rain and snow water to consider. With that being said, could I encapsulate the glycerine for long term controlled release? And what would I use to encapsulate it?