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Making pleurax and other high ri mountants

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  • a.johnw
    Pleurax seems to always refer to a text I can t get my hands on. I found a german site with some info but it doesn t translate well and seems to rely on an
    Message 1 of 10 , Mar 1 7:40 AM
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      Pleurax seems to always refer to a text I can't get my hands on. I
      found a german site with some info but it doesn't translate well and
      seems to rely on an excess of phenol.

      A recipe from what should be a reliable source states
      Phenol crystals 100g
      Sulphur 40g
      Sodium Sulphide 3g
      Isopropyl alcohol 100ml
      (Hepworth 1994:21)

      The German site seemed to suggest that the sodium sulphide is a
      catalyst and infers that there is some heat generated at that stage
      hence the excess phenol which may boil off. They suggest processing it
      at 160c.
      Boiling point of phenol is 181.6C melting at 40.5. Sulphur melts at
      115c. They seemed to have stirred the resin formed for several hours
      at 160. That is then dissolved in the ipa. ri 1.67

      Hyrax seems to be just naphthalene dissolved in toluene? ri 1.82

      Polystyrene also seems to be a high ri mountant eg
      Polystrene 15.75g
      Toluene 50ml
      Methylene idodide 200g
      ri 1.75

      Straight polystyrene ri 1.60

      Is this white expanded polystyrene?

      Any comments on suitability of any of these and or others and making
      them? I'm aware of naphrax (naphthalene formaldehyde ri 1.71).

      John
    • brn_matsumoto
      John: I can t comment on the old mountants that you listed--a fascinating list, by the way, and in its own right well worth reading. You might want to check
      Message 2 of 10 , Mar 1 8:10 AM
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        John:

        I can't comment on the old mountants that you listed--a fascinating
        list, by the way, and in its own right well worth reading.

        You might want to check this site;

        http://micrap.selfip.com:81/micrapp/media.htm

        They sell Zrax--a mountant that Klaus Kemp also has used in his
        commercial preparations for diatom. It is very reasonable in price, is
        soluble in toluene, and you have plenty of links on how to use it with
        diatom preparations. It has a rated I.R. of 1.7.

        I hope this helps.

        Brian
      • a.johnw
        Hi Brian I know Klaus sells Zrax and may well use it but am still curious. I think I might also prefer to sniff ipa rather than toluene. The interesting ones
        Message 3 of 10 , Mar 1 8:59 AM
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          Hi Brian I know Klaus sells Zrax and may well use it but am still
          curious. I think I might also prefer to sniff ipa rather than toluene.

          The interesting ones in some ways are the naphthalene based ones -
          they might remind me of childhood and my granny's wardrobe and furniture.

          On zrax I have had one of Klaus's slides bubble seemingly from very
          very modest heat from the scope's lamp. They went away after a few
          days but the diatoms moved.

          John

          --- In Microscope@yahoogroups.com, "brn_matsumoto" <brn_matsumoto@...>
          wrote:
          >
          > John:
          >
          > I can't comment on the old mountants that you listed--a fascinating
          > list, by the way, and in its own right well worth reading.
          >
          > You might want to check this site;
          >
          > http://micrap.selfip.com:81/micrapp/media.htm
          >
          > They sell Zrax--a mountant that Klaus Kemp also has used in his
          > commercial preparations for diatom. It is very reasonable in price, is
          > soluble in toluene, and you have plenty of links on how to use it with
          > diatom preparations. It has a rated I.R. of 1.7.
          >
          > I hope this helps.
          >
          > Brian
          >
        • Charlie
          John, Some of the optical cements are very intriguing. I ve used Norland NOA 61 (UV cured), but that s got a RI of 1.56 and you seem to be looking for
          Message 4 of 10 , Mar 1 2:11 PM
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            John,

            Some of the optical cements are very intriguing. I've used Norland NOA
            61 (UV cured), but that's got a RI of 1.56 and you seem to be looking
            for something higher. There are a couple two components cements listed
            here that I've been curious to try:

            http://www.emsdiasum.com/SUMMERS/OPTICAL/cements/cements/cements.html#c59

            With an additional component you can get the RI up to 1.61. Not as
            high as Zrax or some of the others you have mentioned, but easy to use
            and should made a nice hard permanent mount with no specimen "migration".



            --- In Microscope@yahoogroups.com, "a.johnw" <a.johnw@...> wrote:
            >
            > Hi Brian I know Klaus sells Zrax and may well use it but am still
            > curious. I think I might also prefer to sniff ipa rather than toluene.
            >
            > The interesting ones in some ways are the naphthalene based ones -
            > they might remind me of childhood and my granny's wardrobe and
            furniture.
            >
            > On zrax I have had one of Klaus's slides bubble seemingly from very
            > very modest heat from the scope's lamp. They went away after a few
            > days but the diatoms moved.
            >
            > John
            >
            > --- In Microscope@yahoogroups.com, "brn_matsumoto" <brn_matsumoto@>
            > wrote:
            > >
            > > John:
            > >
            > > I can't comment on the old mountants that you listed--a fascinating
            > > list, by the way, and in its own right well worth reading.
            > >
            > > You might want to check this site;
            > >
            > > http://micrap.selfip.com:81/micrapp/media.htm
            > >
            > > They sell Zrax--a mountant that Klaus Kemp also has used in his
            > > commercial preparations for diatom. It is very reasonable in price, is
            > > soluble in toluene, and you have plenty of links on how to use it with
            > > diatom preparations. It has a rated I.R. of 1.7.
            > >
            > > I hope this helps.
            > >
            > > Brian
            > >
            >
          • brn_matsumoto
            Hi John: I have always wanted to play with some of the really high mounting medium--but I lacked the time. But you may wish to check the following:
            Message 5 of 10 , Mar 1 10:06 PM
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              Hi John:

              I have always wanted to play with some of the really high mounting
              medium--but I lacked the time. But you may wish to check the following:

              http://www.cargille.com/meltmount.shtml

              They have this Meltmount which looks easy to use--never tried, but I
              did buy a stick that I intend to try.

              Meltmount* 1.704 has a refractive index (ND @ 25°C) of 1.704, similar
              to naphrax, and an Abbe V dispersion of 24.

              They have something which is really intriguing--but it may be too
              expensive and too dangerous.

              REFRACTIVE INDEX MELTS

              Ranges from 2.12 to 2.31. Low melting solid, warm to use. Solidifies
              upon cooling. Formulated with arsenic tribromide, arsenic disulfide
              and selenium. Toxic and corrosive.

              I believe it sells for $147 for a quarter oz, a little too expensive
              for me.

              Brian



              --- In Microscope@yahoogroups.com, "a.johnw" <a.johnw@...> wrote:
              >
              > Hi Brian I know Klaus sells Zrax and may well use it but am still
              > curious. I think I might also prefer to sniff ipa rather than toluene.
              >
              > The interesting ones in some ways are the naphthalene based ones -
              > they might remind me of childhood and my granny's wardrobe and
              furniture.
              >
              > On zrax I have had one of Klaus's slides bubble seemingly from very
              > very modest heat from the scope's lamp. They went away after a few
              > days but the diatoms moved.
              >
              > John
              >
            • DonH
              ... These are nasty, as the formula suggests. I have seen microscopes on which these very high index preparations were used: green and brown corrosive crusts
              Message 6 of 10 , Mar 2 6:31 AM
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                > They have something which is really intriguing--but it may
                > be too
                > expensive and too dangerous.
                >
                > REFRACTIVE INDEX MELTS
                >
                > Ranges from 2.12 to 2.31. Low melting solid, warm to use.
                > Solidifies upon cooling. Formulated with arsenic tribromide, arsenic
                > disulfide and selenium. Toxic and corrosive.


                These are nasty, as the formula suggests. I have seen microscopes on which these very high index preparations were used: green and brown corrosive crusts are the order of the day. These media have their uses, but one needs to be certain that the necessity of using them outweighs the risk and the high maintenance involved with use, cleanup, and disposal.

                Best,
                Don
              • Mark Burgess
                Making Pleurax generates huge amounts of poisonous fumes and you should not try it if you do not have a fume cabinet (opening the windows won’t save you).
                Message 7 of 10 , Mar 2 7:00 AM
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                  Making Pleurax generates huge amounts of poisonous fumes and you should not
                  try it if you do not have a fume cabinet (opening the windows won�t save
                  you). You also need a long period of reflux, as far as I remember. I�d buy
                  it off the shelf.



                  The polystyrene you mention is not the expanded stuff but the high mw
                  powder.



                  Best wishes



                  Mark Burgess


                  2009/3/1 a.johnw <a.johnw@...>

                  > Pleurax seems to always refer to a text I can't get my hands on. I
                  > found a german site with some info but it doesn't translate well and
                  > seems to rely on an excess of phenol.
                  >
                  > A recipe from what should be a reliable source states
                  > Phenol crystals 100g
                  > Sulphur 40g
                  > Sodium Sulphide 3g
                  > Isopropyl alcohol 100ml
                  > (Hepworth 1994:21)
                  >
                  > The German site seemed to suggest that the sodium sulphide is a
                  > catalyst and infers that there is some heat generated at that stage
                  > hence the excess phenol which may boil off. They suggest processing it
                  > at 160c.
                  > Boiling point of phenol is 181.6C melting at 40.5. Sulphur melts at
                  > 115c. They seemed to have stirred the resin formed for several hours
                  > at 160. That is then dissolved in the ipa. ri 1.67
                  >
                  > Hyrax seems to be just naphthalene dissolved in toluene? ri 1.82
                  >
                  > Polystyrene also seems to be a high ri mountant eg
                  > Polystrene 15.75g
                  > Toluene 50ml
                  > Methylene idodide 200g
                  > ri 1.75
                  >
                  > Straight polystyrene ri 1.60
                  >
                  > Is this white expanded polystyrene?
                  >
                  > Any comments on suitability of any of these and or others and making
                  > them? I'm aware of naphrax (naphthalene formaldehyde ri 1.71).
                  >
                  > John
                  >
                  >
                  >


                  [Non-text portions of this message have been removed]
                • a.johnw
                  I personally would not go near the mountants formulated with the same sort of substances eg realgar. John ... on which these very high index preparations were
                  Message 8 of 10 , Mar 2 8:18 AM
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                    I personally would not go near the mountants formulated with the same
                    sort of substances eg realgar.

                    John

                    --- In Microscope@yahoogroups.com, DonH <djhmis@...> wrote:
                    >
                    > > They have something which is really intriguing--but it may
                    > > be too
                    > > expensive and too dangerous.
                    > >
                    > > REFRACTIVE INDEX MELTS
                    > >
                    > > Ranges from 2.12 to 2.31. Low melting solid, warm to use.
                    > > Solidifies upon cooling. Formulated with arsenic tribromide, arsenic
                    > > disulfide and selenium. Toxic and corrosive.
                    >
                    >
                    > These are nasty, as the formula suggests. I have seen microscopes
                    on which these very high index preparations were used: green and brown
                    corrosive crusts are the order of the day. These media have their
                    uses, but one needs to be certain that the necessity of using them
                    outweighs the risk and the high maintenance involved with use,
                    cleanup, and disposal.
                    >
                    > Best,
                    > Don
                    >
                  • forgerii
                    Those high RI mountants ARE nasty, both from a health standpoint AND from the equipment damage point of view. Avoid them if possible! Solutions bade from
                    Message 9 of 10 , Mar 2 8:57 AM
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                      Those high RI mountants ARE nasty, both from a health standpoint AND
                      from the equipment damage point of view. Avoid them if possible!

                      Solutions bade from styrofaom and from powdered polystyrene seem
                      identical to me. The original materials Are different, but once
                      dissolved they seem the same.

                      John Odom
                    • a.johnw
                      It s also possible to get clear polystyrene in sheet form. Some where I saw a comment about shrinkage being a problem. The iodine compound that can be mixed
                      Message 10 of 10 , Mar 2 9:37 AM
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                        It's also possible to get clear polystyrene in sheet form. Some where
                        I saw a comment about shrinkage being a problem.

                        The iodine compound that can be mixed with it to boost the ri to 1.75
                        seems to decompose in light and go brown on it's own. Wonder what it
                        does in polystyrene.

                        John

                        --- In Microscope@yahoogroups.com, "forgerii" <forgerii@...> wrote:
                        >
                        > Those high RI mountants ARE nasty, both from a health standpoint AND
                        > from the equipment damage point of view. Avoid them if possible!
                        >
                        > Solutions bade from styrofaom and from powdered polystyrene seem
                        > identical to me. The original materials Are different, but once
                        > dissolved they seem the same.
                        >
                        > John Odom
                        >
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