simple question???

[bdhedhy19]

Dear all!
I have a question about viscosity? Viscosity sound like simple test, but i have nonoxynol-12 sample which has a tendency of hazy appearance at room temperature. I have to test the viscosity on it, but it seems like higher density particles does not completely dissolve in solution at 25C during winter time and viscosity shows higher than specification.
I wonder if i can warm the sample at certain temperature and than bring back to 25C per procedure and check the viscosity. Can i do that without effecting the chemical structure of the material.
Please let me know at your earliest convenience. i would really appreciate!!!
Thanks

[tom jupille]

I would assume the procedure simply calls for a temperature of 25 and does not specify whether you approach it from below or from above. Given its wide use in consumer products, I can't imagine it having any stability issues for a short time at say, 35 or 40 degrees, which should be enough for your purpose.

[Don_Hilton]

While I am a chromatographer and not a rheologist, I'll toss some ideas back to you...

It may be worth checking with the person or group that set the specification to see what should be done.

The nonoxynol-12 may show a phase change at low temperature and is very slow to change back at 25C. In this case, warming may well make the solution to be a uniform phase - but that is a change of structure of the solution. And, it may even be one that you want. But if the change is required to pass QC, it might require entire drums of nonoxynol-12 be run through a temperature cycle to ensure that the contents have the desired property. The QC specification may relate to a parameter important in processing the nonoxynol-12.

If you warm the nonoxynol-12, you may have to be concerend about what happens when it cools back to 25C. Does the material have a "memory" of being warmed? If there is "memory" of being warmed, the temperature cycle would have to be carefully controlled and there would have to be a specified delay to allow the liquid to obtain the proper degree of structure before you attempt to measure viscosity.

[bdhedhy19]

Thanks Tom and Thanks Don for your reply and explanation!!!
Really appreciated