0.5mm Platinum wire

Is there any reason the platinum wire needs to be so thick? Could a thinner wire, say 0.2mm, be used instead if it is anchored to some sort of framework to hold its shape?


  • https://docs.google.com/a/uconn.edu/file/d/0B6RE82086JGFN3dEQlJzS0x3T2M/edit?usp=sharing


    Just finished building this 10 minutes ago. It's curing now. That's 0.2mm Pt wire, with a plastic backing I cut out of the bottom of a Petri dish.
  • Apologies for posting links that were locked down - I opened the sharing settings - should be visible to all now.
  • Have you considered making a coated plate instead of platinum wire to cut down on costs?
  • abachmanabachman Posts: 3
    Thanks I am going to try a similar plan with thiner wire and some PP posts with the wire looped through in a zig-zag pattern. Here is a rough prototype I just whipped up (no wire):


    obviously I will have to replicate this in the 60 mL Nalgene container...
  • achungachung Posts: 7
    So has anyone actually tried the 0.2mm?
  • MNGMNG Posts: 6
    edited June 2013
    Here is our chamber. It is made w/ .2mm We make as much as possible out of polycarb and/or acrylic so that we can solvent weld it. The wire ports were sealed w/aquarium silicone. We also used it on the lid as it is polypropylene and can only be friction/heat welded. All our ports are luer for quick connecting

    During electrophoresis, we overheated it so much that it melted and burned the acrylic and melted some of the solder, but it still works. I do wonder if the anode was used up a bit. It seems thinner.

  • @achung my newest chamber actually uses .127mm wire. Even this thinner stuff seems to hold up fine - especially if you support it with a plastic backing.

    @MNG nice setup. I'll have to look into that aquarium silicone.
  • For those of you trying thinner wire, have you actually tried clearing yet? I have also tried thinner wire, as thin as 32 gauge, but have noticed that I start having issues with anything smaller than about 28 gauge when I actually start clearing. This is primarily due to the amount of surface area for buildup of deposit on the anode. Keeping the electrodes clean seems to be easier if you don't go too small.
  • MNGMNG Posts: 6
    We have been using .2mm wire to save cost. The anode dissolves within a week of electrophoresis. Has anyone noticed loss material on the anode with .5mm wire?

    FYI, We also built a chamber with stainless steel plate electrodes - not a good idea, as at a minimum we expected the current to leach chromium in to the buffer, however the full 5 liters was a thick rust color within 60min of starting.

    The next electrodes will be carbon. Should have that started in the next few days.

    We have also changed the box to use an internal snorkel to pull from the top of the chamber and funnel the effluent to the bottom of the chamber and exit. This negates the need to cut and glue the lid, simplifying construction. The chamber does not tip over or have to be secured because of a hose on the top.
  • lijunlijun Posts: 14
    I' ve observed obvious anode dissolving only when I used the copper wire (0.5mm)as the electrode.When I replaced the electrodes with Pt wires (0.5mm),the cathode electrode became black but no more apparent dissolving being oberved again.
  • I've noticed the platinum 0.5 mm anode (non-blackened electrode) thinning after >200 hours of use.
  • By the way, you can find cheaper platinum on Amazon. I bought some from SIgma and a supplier on Amazon. They were identical except the Amazon wire was 1/2 the price.
  • KeithSiewKeithSiew Posts: 24
    @Suzschindler Don't suppose you provide that link for amazon and what purity/diameter the wire was?
  • aysegulaysegul Posts: 33
    For those of you trying gold wire ? I think it is cheaper than the platinum wire (http://www.sigmaaldrich.com/catalog/product/aldrich/267201?lang=en&region=TR).
  • Unfortunately, it looks like the Amazon supplier is out. I have a feeling a lot of people are making CLARITY chambers....
  • HyewonHyewon Posts: 7
    @MNG Have you tried with carbon electrode? Did you have any issuses with it?
  • I'm going to try CLARITY by passive cleaning in some samples in a few weeks. I'm already thinking in using the ETC, but I'm worried about the cost of the wires.
    Did anyone had luck with other materials? or overcame the dissolving/blackening issue?
  • MNGMNG Posts: 6
    Tried carbon as well and it too was a failure, showing electrode degradation in 2-3 hours (@ 30V). Turned everything black and left a residue that stuck to my next 3 brains, after cleaning the system and changing the filters.
  • MOGMOG Posts: 3
    Did anyone try Pt wire from sources other than Amazon, Sigma or Alfa Aesar?
    If so, do you have advice about the characteristics to look for? I found a site that sells Pt wire at a reasonable price and describes the diameter, purity and 'temper' of the wire but not the resistence. Does anyone know what hard tempered wire is and whether it will perform well in this application?
  • jflynnjflynn Posts: 6
    @MOG Was that from a company called 'GoodFellows'?
  • heyhowieheyhowie Posts: 1
    @MOG A good source for Pt wire is http://buyplatinumwire.com by Surepure Chemetals. They ship quickly and have a good selection. They have .0006 in. diameter platinum wire all the way up to .128 in. diameter and can make other diameters too.

    To answer your question about temper, you can think of the temper of wire like taffy (kind of like a cylindrical Starburst).

    When wire (or taffy) is "annealed" (heated), it gets softer. When you pull the ends of it, it will stretch a lot (i.e., it has high "elongation"). And you don't have to pull very hard before it eventually breaks into two pieces (i.e., its ultimate tensile strength is fairly low).

    When wire is drawn through a die (i.e., pulled through a small circle to make its diameter smaller), it gets harder. When you pull the ends of harder temper wire (or cold taffy), it won't stretch very far (i.e., it has low elongation). And you'll have to pull the ends using a lot of force to get it to break into two pieces (i.e., its ultimate tensile strength is fairly high).

    To keep drawing wire down from a larger size, it occasionally needs to be annealed (heated). There are various standard American Wire Gauge (AWG) sizes. 0.5 mm is roughly equivalent to 24 gauge on the AWG scale. To get "one die hard" 24 gauge wire, you would anneal it at 23 gauge (0.573 mm) and then draw it through the 24 gauge die. To get "two dies hard" 24 gauge wire, you would anneal it at 22 gauge (0.644 mm) and then draw it through the 23 gauge die and then the 24 gauge die. And so on.
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