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| Nomen Nescio... |
 Posted: Mon Oct 12, 2009 11:40 am |
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I previously got some help here locating indicator mol sieves.
I need that, again, and more.
I want good old blue (cobalt) indicator sieve for treating
peroxide forming solvents (e.g., Et2O, dioxane). According
to the patent literature, other metal salts have been used
as blue to pink indicators in sieves but I think cobalt
chloride is the most common.
SEE: Deperoxidation of ethers. A novel application of self-
indicating molecular sieves
David R. Burfield
J. Org. Chem., 1982, 47 (20), pp 3821–3824
DOI: 10.1021/jo00141a003)
The problems are:
1. Fluka has blue beads for $350/kg!!!
2. I can find plenty of "mixed" beads: 95% plain 3A sieve
with a few blue beads sprinkled in but that's a waste.
3. I have just also found "neoblue" and "orange" indicator
sieves here:
http://www.cwaller.de/english.htm?esili.htm~information
DOES ANYONE KNOW what the indicators are in the neoblue
and orange sieves are? I kind of doubt that they will
destroy peroxides, but I'm wondering what they are
anyway.
THANK YOU. |
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| Bolaleman... |
| Posted: Thu Oct 15, 2009 8:54 am |
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On Oct 12, 5:40 pm, Nomen Nescio <nob... at (no spam) dizum.com> wrote:
[quote:5c54245740]I previously got some help here locating indicator mol sieves.
I need that, again, and more.
I want good old blue (cobalt) indicator sieve for treating
peroxide forming solvents (e.g., Et2O, dioxane). According
to the patent literature, other metal salts have been used
as blue to pink indicators in sieves but I think cobalt
chloride is the most common.
SEE: Deperoxidation of ethers. A novel application of self-
indicating molecular sieves
David R. Burfield
J. Org. Chem., 1982, 47 (20), pp 3821–3824
DOI: 10.1021/jo00141a003)
The problems are:
1. Fluka has blue beads for $350/kg!!!
2. I can find plenty of "mixed" beads: 95% plain 3A sieve
with a few blue beads sprinkled in but that's a waste.
3. I have just also found "neoblue" and "orange" indicator
sieves here:http://www.cwaller.de/english.htm?esili.htm~information
DOES ANYONE KNOW what the indicators are in the neoblue
and orange sieves are? I kind of doubt that they will
destroy peroxides, but I'm wondering what they are
anyway.
THANK YOU.
[/quote:5c54245740]
what is used are both inorganic and organic colorants. See for
instance U.S. Pat. No. 4,018,870 (http://www.patentstorm.us/patents/
5968242/description.html) where describes the synthesis of silicon-
containing molecular sieves in the presence of methylene blue and
acriflavine as templates is described, both of which are water-soluble
basic dyes. In this so-called template synthesis, the molecular sieve
is synthesised in the presence of a compound serving as molecular
template. The templates, in the present case the dye molecules, are
thus inserted into the forming cavities of the corresponding molecular
sieve. By this principle, specific molecular sieves are accessible,
depending on the template. To obtain molecular sieves having free
pores and cavities, the organic template compounds retained in the
cavities of the molecular sieves so obtained are driven off by
heating.
Zeolites 4 (1984), p. 30-34, gives a description of the so-called ship-
in-the-bottle synthesis of cobalt phthalocyanines, nickel
phthalocyanines and copper phthalocyanines (Pc) in the faujasite
zeolite. In this method, the cations present in the zeolite are first
exchanged for the cited transition metal cations. In a subsequent
step, the corresponding Pc complex is then formed inter alia in the
cavities of the faujasite by the addition of ortho-phthalodinitrile.
The Pc complexes formed in the cavities normally do not diffuse from
the cavities for sterical reasons. However, in some applications this
happens unwantedly.
This is just one example of quite a series of compounds used as
colorants and humidity indicators in zeolites. For your purpose of
solvent drying and peroxide removal, I suggest to use the standard
zeolites with cobalt chloride as indicator. By the way, fluka is not
the only company offering this product. Just have a look at Merck,
Sigma-Aldrich, Riedel Haen, etc.
Bolaleman
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| Bill Penrose... |
| Posted: Thu Oct 15, 2009 5:21 pm |
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On Oct 12, 2:40 pm, Nomen Nescio <nob... at (no spam) dizum.com> wrote:
[quote:87b96af77c]DOES ANYONE KNOW what the indicators are in the neoblue
and orange sieves are?
[/quote:87b96af77c]
The blue molecular sieves are so expensive, it's typical to put a few
blue granules in with a larger quantity of uncolored granules.
DB |
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| Bolaleman... |
| Posted: Sat Oct 17, 2009 10:20 am |
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Guest
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On 15 oct, 23:21, Bill Penrose <dangerousb... at (no spam) gmail.com> wrote:
[quote:74a3f72fa1]On Oct 12, 2:40 pm, Nomen Nescio <nob... at (no spam) dizum.com> wrote:
DOES ANYONE KNOW what the indicators are in the neoblue
and orange sieves are?
The blue molecular sieves are so expensive, it's typical to put a few
blue granules in with a larger quantity of uncolored granules.
DB
[/quote:74a3f72fa1]
If you care too much about the price you also can regenerate the
molecular sieves. Methods for regeneration of molecular sieves include
pressure change (as in oxygen concentrators), heating and purging with
a carrier gas (as when used in ethanol dehydration), or heating under
high vacuum. What I did during my chem study is the last one. I heated
the sieve to about 90 - 110 degC under vacuum for about 5 hours. If
the sieve only is used to eliminate water and peroxides traces from
ethers, this method is sufficient. If you use the sieve for
eliminating semi-volatile organic compounds, it's necessary to heat
and purge with dry nitrogen as carrier gas.
Bolaleman
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