Todd, Are you working with oxygen sensitive or moisture sensitive samples (or both)? If it's just moisture sensitive, then you can use regular 2-sided tape from your local office supply and polypropylene film to seal samples in polycarbonate or aluminum holders (or even pellets if you're lucky enough to be able to press pellets that hold their shape). Chemplex Industries is where I have gotten the polypropylene films I have used (and Kapton as well - www.findtape.com also has a good selection of Kapton tape). I used this method with many samples that involved heavily chlorided titanium on silica and had few problems if they're used within 5-7 days after packing in a glove box (the samples with problems resulted from improperly sealed samples). You can get jars (baby food jars work very well to ship individual samples) to store the samples for shipping and if you pack the jars in the glove box, you will have the box atmosphere in the jars, for a little while anyway. A note on oxygen sensitivity (and to an extent moisture sensitivity): you probably already know this, but I'll say it anyway...if cardboard is present in the role of Kapton tape, you may have oxygen/water diffusion from the cardboard for a few days after you take it into the box. Our rule of thumb was to pull vacuum on anything involving cardboard for at least 48 hrs before taking it into the box. All that to say, take your supplies into the box a few days ahead of time to allow your box catalyst to take care of any residual oxygen/water that make their way in. HTH, -Richard On Wed, Aug 5, 2009 at 7:27 PM, Scott Calvin wrote:

Hi Todd, I've taken the liberty of posting your question to the Ifeffit mailing list. You're likely to get more accurate and quicker answers to these kinds of questions there.

(For the rest of you: Todd is asking about the technique of preparing air-sensitive samples in a glove box, putting them on Kapton tape, sealing them in plastic bags, and transporting them to the beamline, shooting right through the bags.)

I'll take my shots, though:

It's hard for me to imagine adsorbed oxygen on the Kapton being more significant than the other sources of stray oxygen that can be present in a glove box. After all, the Kapton's in there too. And I don't think it's going to be more significant than the oxygen that diffuses through the plastic bags during transport.

The thinner the Kapton tape, the better, as that will minimize the absorption due to the tape. It used to be hard to find 1 mil Kapton tape with adhesive, but now it's easy. Hephaestus will give you the absorption of Kapton, so you can judge how big an effect it will be at the energies at which you'll work.

--Scott Calvin Sarah Lawrence College

On Aug 4, 2009, at 2:39 PM, Monson, Todd wrote:

Scott,

Thanks. Is it pretty reasonable to assume that the kapton tape that you put your samples on doesn’t have any adsorbed oxygen that could affect your samples? Do you do anything to clean the kapton? Where are some good places to buy the kapton (and do you need to purchase rather thin kapton tape for doing XAFS)?

Thanks again,

Todd

*From:* Scott Calvin *Sent:* August 04, 2009 11:34 AM *To:* Monson, Todd *Cc:* Scott Calvin *Subject:* Re: mossbauer

Hi Todd,

Regular zip-loc bags work just fine. For heat sealers I've used everything from a heat sealer manufactured for the purpose to a little propane torch--even a cigarette lighter should work. Putting one sealed bag inside another, if the energy you're working at allows it, seems to work quite well.

--Scott

On Aug 4, 2009, at 1:15 PM, Monson, Todd wrote:

Scott,

I had another question – what kind of plastic bags and heat sealers do you use for sealing up your air-sensitive XAFS samples? And where could I buy them?

Thanks,

Todd

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