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Freezing Emulsions
Just Curious,
I have read somewhere in this forum that freezing an emulsion will ruin it.
Why?
Do the silver-halide crystals come out of suspension? Do they aglomerate?
Or do the crystals change in some more basic way?
Or is it the gelatin that deteriorates,changing the suspension characteristics of the crystals?
I remember years ago purchasing a pint of Liquid Light. I THINK that I remember the data sheet stating that it COULD be frozen. But that was long ago.
Bill
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My current bottle of Liquid Light says it may be refrigerated or frozen - it's in the freezer now. I have never mixed my own emulsions, so I can't comment on that.
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Freezing can damage the emulsion. But it should be stored well chilled.
Ian
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Ian and PE,
Thanks for the answere. However, my question realy was "What happens to an emulsion when it is frozen and thawed?" I am intrested in the Hows and Whys here.
Call me a life-long three year old.
Bill
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Lets see now, how can I put this in terms that a 3 year old will understand.  JK Bill.
The gelatin loses its ability to peptize silver properly and it also loses water to some extent and ends up being less elastic and the silver halide crystals can then aggregate. This causes coating defects and pepper grain.
PE
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 Originally Posted by Photo Engineer
Lets see now, how can I put this in terms that a 3 year old will understand. JK Bill.
The gelatin loses its ability to peptize silver properly and it also loses water to some extent and ends up being less elastic and the silver halide crystals can then aggregate. This causes coating defects and pepper grain.
PE
I understood that.
I must be younger than I thought!
Actually, however, freezing is and has been practiced in some circles.
That the emulsion will "fail" is by no means a given.
It depends on the emulsion and the technique.
Ray
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Ray;
All well and good, but we found that no emulsion could be made and kept reliably if it were frozen. It was better to refrigerate at 2 - 4 deg C and use a very good bacteriostat/fungicide.
PE
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It may well also depend on what else is in the emulsion. Back in the 70's I was Rockland Colliods first ever UK customer, I only ever bought the one bottle but it had a very aromatic alcohol smell, it may be that it doesn't freeze unless the temperature falls well below 0°C.
But from my experience a frozen emulsion doesn't gel properly when coated, and has other defects, I learnt the hard way. As Ron says close to freezing but not frozen.
Ian
Ian
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Different Goals
Originally Posted by Photo Engineer
Ray;
we found that no emulsion could be made and kept reliably if it were frozen. It was better to refrigerate at 2 - 4 deg C and use a very good bacteriostat/fungicide.
PE
It looks like what you are descrbing was directed at emulsion storage,
and for that I agree. I never store uncoated emulsion frozen.
Ray
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