Sorry about my abrupt actions on 30 July 2023! But, I went back in time some 55 years and did get very emotional, which in turn, triggered my Auto-Immune condition. Perhaps, at some other time, I may relate the events which led to that stage, but for now, it is irrelevant. I would like to now finish my statement to you. Fortunately I am in a better position now because I now know your complete formulation that has pleased you for over 25 years using you VPI device (the same device I have and used for about the same time period) and, I was able to find my misplaced Triton X 100, which was not in my home lab, but in my basement. Also I now understand that your rinse after washing as your standard procedure with deionized water. Please correct me if I got anything wrong!
If you do not mind, I took the liberty to convert your formulation into a parts by weight formulation. I need you to know that I did so for strictly selfish, personal reasons because my mind functions much better in weights and equivalents than in parts by volume. Therefor, your formulation in parts by weight at 20 C. is as follows:
Water, Deionized @ 20 C. 79.022 %
98% Isopropyl Alcohol @ 20 C. 20.865 %
Triton X 100 @ 20 C. 0.113 %
Total 100.000 %
The conversions I used are as follows:
Water, Deionized @ 20 C. = 0.998203
Isopropyl alcohol 100% @ 20 C. = 0.785401
Triton X 100 @ 20 C. = 1.06501
Your 98% Isopropyl alcohol @ 20 C. = 0.789656
Previously I mentioned to use a lesser amount of Isopropanol. This was not to "improve" the formulation, but, merely that it was unnecessary to use the extra percentage that you were using. So, there is no need to alter your existing content of alcohol. However you are using about 5 times as much Triton X 100 (4.96 to be more precise) as necessary.
I am certain that if you reduce your Triton X 100 level about 20% of what you are presently using, that is, volumetrically, you will find the cleaning ability to be about the same. Not much better, not much worse, and, I am referring to the cleaning ability only. I was able to make some calculations and also measurements. We should go by the measurements. Using your formulation as you have been using for years, the Surface Tension at 20 C. (68 F.) is 30.0 dynes/centimeter, and, at 25 C. (77 F) it is 30.7 dynes/centimeter. If you were to agree to my suggestion, and reduce the Triton X 100 as indicated, the Surface Tension at 20 C. (68 F.) is 31.2 dynes/centimeter, and at 25 C. (77 F.) it is 30.9 dynes/centimeter. Yes, if is higher, but, not as significant when you consider that the differential is a resultant of a level 4.96 times greater.
Now, I know, you are aware that your water and IPA demonstrates a relatively rapid evaporation rate similar to Ethanol. IPA is unique in that its’ evaporation rate initially is faster at the onset than at its’ latter stage. Unlike Ethanol and Methanol which are relatively constant. That characteristic is more of an advantage than a disadvantage. I wanted you to be aware, if you were not, because it determines your behavioral processes.
I also know that you know that your IPA/Water blend is azeotropic as is Ethanol/Water. Although Triton X 100 is not a typical primary or secondary alcohol structured surfactant, it is, however, a octyl phenol stemmed, and is terminated with a hydroxyl group. Therefor, the azeotropic characteristics of your blend does carry. a portion of the X 100 along during its rapid evaporation. It may not be as high as the 60% "carry factor" as with Tergitol 15-S-7, but, it certainly would exist at a level of at least 30% to 35%. Sorry I can not be more specific, because I would actually have to determine the value to be specific.
Triton X 100 is a good choice for cleaning records, but, it is a high-foaming, film-forming surfactant. It must have film forming characteristics in order to bo high-foaming. Just think of blowing bubbles as a child. The better the film forming ability, the larger and more stable bubbles can be formed. Unlike Tergitol 15-S-7 which is very low foaming and more of a wetting and leveling agent.
So, unlike the previous incorrect answer you received, your azeotropic rapid evaporating blend of IPA and water is significantly reducing the amount of Triton X 100 remaining on the record. (In this particular case, I am considering a 30 to 35 percent reduction as significant, because you are actually using 4.96 the required amount.). That coupled with your vacuum device you may not need to rinse your records if you lower your concentration of Triton X 100. However, you stated that rinsing is now always part of your process. In that case, may I strongly suggest that you use your 25% parts by volume IPA in deionized water as your rinse media rather than just deionized water. That would be very significant.
Rinsing in only distilled water proved to be a problem. You only need to read my response to @mijostyn, what my wife determined under her microscope. It is worth the read. Most people do not conceive the amount of contaminants in our atmosphere that can cause problems after cleaning. We were discussing Ultrasonics, but it is almost as relevant in this case as well.
Sorry about my late response but my travels to the Hospital for two tests became very complicated, and I had to be kept until yesterdays’ release.
Any other questions, I hopefully will be able to respond more promptly.
Wizzzard
P.S. I expected the Surface Tensions as calculated to be a bit lower, I was surprised a bit at the readings I received. But, we need to go by actual readings and not theoretical calculations. Also, I now also need to correct the recommended level of Triton X 100 I previously informed you of. I stated to use 11 to 12 drops, recommending 12 drops. Now that I located my Triton X 100 the actual amount should be 9 to 10 drops, and 9 drops being a bit more precise. Calculations are good, but actuality is much better. Sorry about that!