How to Remove Water From Isopropyl Alcohol

[Tony]

Great to see you on the forum Dinesh! Welcome

Do you ever recharge your IPA? How do you know when the IPA concentration is getting too low? Or do you simply swap out IPA on a timetable or X amount of plates?

[Dinesh]

Great to see you on the forum Dinesh! Welcome

Thanks!

Do you ever recharge your IPA? How do you know when the IPA concentration is getting too low? Or do you simply swap out IPA on a timetable or X amount of plates?

When the holograms get weak! I don't do a lot of display stuff anymore. Mostly, I'm making notch filters now. We have a spectrophotometer to test the filters and I notice that the efficiency drops after 4 or 5 plates, so I generally renew.

I "recharge" the plates by using the the higher concentration alcohol to make the lower concentration alcohol and the used 100% alcohol to make fresh lower concentration alcohol. This way, there's very little waste, except at the low end.

So, I start with 50%, 75%, 100% cold and 100% hot. After (let's say) 5 plates I throw away the 50%, calculate how much extra water I need to convert the 75% to 50% (taking into account that a certain amount of water gets transferred along with the plate as it goes from water to the first 50% bath - I usually figure it's about 10% weaker due to the water transfer), do the same for the 100% cold to the 75% and transfer the (old) hot 100% to the (cold) 100% tray. Now I refill the hot 100% from the alcohol tank. At the end of the day, I get rid of the 50 and 75% and transfer both the hot and cold 100% to a separate container because they're probably a hair under 100%. The next day, I use this separate container to make the 50% and 75% and use pristine alcohol, from the tank to make the hot and cold 100%.

[holorefugee]

A bench Abbe refractometer would make this measurement simple.

[dcgman]

to find the purity of IPA, use a hydrometer, or if you have accurate scales, weigh a litre of the stuff and determine its density. There's plenty of info on the web about the density of pure IPA.
Once you are confident you've got hold of some very pure IPA, dilute it to 90%, 77%, 50% (i.e. dilutions you are going to use in your series of processing baths) and use one of the two techniques mentioned above to find the density at a given dilution. Note these figures down-you'll then be able to use these figures at a later date to work out the approximate dilution of a given bath

[Jeffrey Weil]

I think Dinesh has it right. Let the hologram do the talking. If the holo's are coming out uniform and all the same, your fine. If not, then refresh.

The hologram always knows best. And in this case it's speaking clearly, usually there more cryptic.

Jeff

[Engineer Devi Lal]

Please tell me how remove to moisture content from isopropyl alcohol but I want to moisture content not more than (.10%) and present of moisture content 10% this solvent

[stefanosica]

anhydrous sodium sulfate is widely used as an inert drying agent, to remove trace amounts of water from organic solutions. It is more effective, but slower acting, than magnesium sulfate. It is only effective below approximately 30°C, but can be used with a variety of materials as it is quite chemically inert. Sodium sulfate is added to the solution until the crystals no longer clump;

[stefanosica]

For large amount of water to remove from organic solvent https://www.amazon.com/Chemglass-CG-133 ... 189&sr=8-1