Hi Barry- I have tried pumps and spinning to make oriented clay samples. The best way I found is to dry thin suspensions (e.g. 5-10 mg or less) on Si wafers that were cut parallel to a crystallography dimension that I forget, but that is described in one of my papers. The wafers come as 6 inch disks which can then be scored with a diamond pen, snapped to right size, and then the cleavage pieces glued to glass substrates. The main XRD peak for the Si is >60 degrees, so it does not interfere, but a tiny peak may show up at small angles. The higher angle clay peaks will lose some intensity compared with theoretical values because the sample is not infinitely thick. If the clay is mixed with a PVP solution prior to drying on the slide, all swelling disappears, and the pattern gives super oriented intensities from very small samples, and a clear view of the so called fundamental clay (especially illite) crystals without the surface swelling effects (inter particle diffraction). The clay thickness distributions can then be calculated using the program MudMaster to elucidate crystal growth mechanisms and growth history. Denny Sent from my iPhone > On Sep 8, 2022, at 9:15 AM, Barry Bickmore via MSA-talk <msa-talk@minlists.org> wrote: Sent from my iPhone Begin forwarded message: > From: Dennis Eberl <ddeberl@gmail.com> > Date: September 8, 2022 at 11:19:47 AM MDT > To: Barry Bickmore <bbickmore@comcast.net> > Subject: Re: [MSA-talk] pumps for filtration setup > > Hi Barry- > I have tried pumps and spinning to make oriented clay samples. The best way I found is to dry thin suspensions (e.g. 5-10 mg or less) on Si wafers that were cut parallel to a crystallography dimension that I forget, but that is described in one of my papers. The wafers come as 6 inch disks which can then be scored with a diamond pen, snapped to right size, and then the cleavage pieces glued to glass substrates. The main XRD peak for the Si is >60 degrees, so it does not interfere, but a tiny peak may show up at small angles. The higher angle clay peaks will lose some intensity compared with theoretical values because the sample is not infinitely thick. If the clay is mixed with a PVP solution prior to drying on the slide, all swelling disappears, and the pattern gives super oriented intensities from very small samples, and a clear view of the so called fundamental clay (especially illite) crystals without the surface swelling effects (inter particle diffraction). The clay thickness distributions can then be calculated using the program MudMaster to elucidate crystal growth mechanisms and growth history. > Denny > > Sent from my iPhone > >>> On Sep 8, 2022, at 9:15 AM, Barry Bickmore via MSA-talk <msa-talk@minlists.org> wrote: >>> >> Hi everyone, >> >> I have been trying, off and on, to set up my lab to do more oriented clay mounts, and I would like to do the filter paper method. One thing I keep running into is that after some minimal amount of clay is deposited on the filter paper, it just stops pulling any more liquid through. After trying a few different things, I’ve concluded that my roughing pump probably isn’t pulling a strong enough vacuum. It’s an Edwards E2M1.5, which is supposed to get down to a max vacuum of 2.3 x 10^-3 Torr. Does anyone with any experience with these setups have any idea how strong of a vacuum pump I need to get it to work well? It may be that my pump just isn’t working as well as it’s supposed to, so I don’t need to buy some ridiculously expensive turbo pump. Any advice about how to set it up, recommendations on pump models that seem to work well, etc., would be appreciated. >> >> Thanks! >> >> Barry Bickmore >> Professor of Geological Sciences >> Brigham Young University >> >> _______________________________________________ >> MSA-talk mailing list -- msa-talk@minlists.org >> To unsubscribe send an email to msa-talk-leave@minlists.org