Sciencemadness Discussion Board

Which should I use H2O2 of NaOCl to clean/sterilize virgin fibers/silk

RogueRose - 1-10-2019 at 07:57

I have some fiberous material that is similar to cotton, in that it comes from a plant (milkweed), but is more silky and fluffy - and is a great insulator very similar to goose/duck down. The problem is that there are some tiny bugs mixed in from harvest as well as some very minor mildew/mold on some ends of the strands (invisible unless under magnification & causes slight discoloration). The stuff is pretty water repellent/resistant but it will take on water if the air is pressed out of the fiber while under water.

I figured I might soak the fibers in a "bleach" solution of either NaOCl or H2O2 with a little soap. I'm wondering which of these would be less likely to cause any damage to the fibers. I'm wondering if using pure 3% H2O2 would be fine b/c it doesn't seem to damage clothing when I apply it, but 3% bleach will definately damage the fabric - so IDK why the hypochlorite is more effective/damaging in bleaching.

AJKOER - 18-10-2019 at 13:41

Try some aqueous CuSO4 whose prep I have explored in one of my threads (see http://www.sciencemadness.org/talk/viewthread.php?tid=151055... ) where I employed a piece of copper metal, widely available NaHSO4, along with 3% H2O2, some NaCl and a source of carbon.

But why a soluble copper salt?

Because copper ions, even in tiny amounts, are highly toxic to microorganisms.

Unfortunately, fish and other small animals find copper problematic, so be careful in your application and discarding excess solution (apply Washing Soda, Na2CO3).
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Bleach approach is possible in very dilute amounts, but may still damage the fiber.

arkoma - 18-10-2019 at 13:57

https://patents.google.com/patent/US5480788A/en

Interesting patent. Sez H2O2 in an alkaline solution (above pH 8.3) is effective

Sulaiman - 18-10-2019 at 20:11

Quote: Originally posted by arkoma  
https://patents.google.com/patent/US5480788A/en

Interesting patent. Sez H2O2 in an alkaline solution (above pH 8.3) is effective

OxiClean (and competitors similar products) domestic powdered bleach is H2O2 complexed with Na2CO3 ... sodium percarbonate.

AJKOER - 19-10-2019 at 04:28

I do NOT recommend OxiClean, if you want a friendly agent. However, per the comments below, you likely have a PAA mix that I recall is recommended for biological warfare decontamination (see my comments and references cited at https://www.sciencemadness.org/whisper/viewthread.php?tid=77... ), so possibly great when employed with tap water rich in Mn, but do read the warning labels and discussion at a prior thread, extract below, link: https://www.sciencemadness.org/whisper/viewthread.php?tid=73... :

Quote: Originally posted by AJKOER  
First, unlike Sodium perborate, Sodium percarbonate is chemically just an addition compound of Na2CO3 and Hydrogen peroxide.

Also, while Sodium carbonate and Sodium percarbonate (basically Na2CO3 and 3Na2CO3.2H2O2) are often listed as the main ingredients in typical chlorine free bleach, an additive, TAED, which acts as a key activator (see, for example, https://en.m.wikipedia.org/wiki/OxiClean ) is not even listed on the label. TetraAcetylEthyleneDiamine is apparently commonly employed as a bleach activator in many laundry products (see https://en.m.wikipedia.org/wiki/Tetraacetylethylenediamine ). TAED reacts with H2O2 in alkaline conditions (referred to as perhydrolysis) creating, in part, Peracetic Acid. The latter PAA is actually preferred over sluggish H2O2 for bleaching. In other words, it is not the H2O2 as the active bleaching agent, but PAA created in situ. So, other than possibly misleading implying that eco friendly hydrogen peroxide is the active agent, it is, in reality, PAA, a probematic compound with associated health concerns (see Marquand, E. C.; et al. , 2007. "Asthma Caused by Peracetic Acid-Hydrogen Peroxide Mixture". J. Occup. Health. 49 (2): 155–158.). Here is a MSDS on an actual PAA mix ( 76-61% water, PAA 20-35%, 3% Acetic acid and 1% H2O2): https://www.google.com/url?sa=t&source=web&rct=j&... which is far from friendly but does eventually totally decompose into harmless O2, CO2, H2O,...

As such anyone using a commercial percarbonate product should at least be aware of safety issues and that one is likely employing a Peracetic acid mix.

Legally, I find it is interesting that one can list main ingredients and not actualy cite active agents. The warning labels on the product are certainly ample and displayed in different languages, and should not be dismissed under the misconception that this is just a harmless washing soda and H2O2 mix (that is, absent TAED, which it may approach under totally dry condtions) but apparently, in the presence of TAED, moisture (like in ones lungs), water vapor or in water solutions, it may no longer be quite so friendly.

[Edited on 23-4-2017 by AJKOER]


[Edited on 19-10-2019 by AJKOER]

clearly_not_atara - 19-10-2019 at 07:42

Hypochlorite is more damaging than H2O2 because it has a lower barrier to reaction (activation energy). OxiClean is H2O2 with some catalysts that lower the activation energy, putting it between H2O2 and bleach.

But I don’t see why simply baking it in an oven at about 80 C wouldn’t work?