Capillary vs. Me & a Toothbrush

Hello,

Allow me to introduce mt partner in crime this post...

The Toothbrush

More specifically, an electric toothbrush.

You probably want some explanation for this. Well, I've started in the lab.

Around the beamlines, there are a number of labs, dealing with the experiments and preparation for the beamline work. This includes a fume cupboard, a vacuum chamber, several furnaces, a scanning electron microscope... amongst lots of other things.

Two things I was being taught to use fresh of Monday morning was the  

1. Raman spectroscopy In this, molecular vibrations (known as phonons) interacts with photons (little packets of light) from a laser. The photons scatter inelastically; often photons can be absorbed by the sample and re-emitted at a different energy. This shift in energy can be described as a 'fingerprint' of a particular type of molecule. This information can tell us a lot about the bonds and atoms in a molecule.
2. IR machine performs InfraRed (sic) spectroscopy. It can measure the interactions of a sample with IR light. 

The lovely PostDoc Research Assistant was giving me some tuition in how to use the Raman Spectroscopy. I quickly learnt the hardest thing was to get the machine to focus, but as we were going along, she realised she could use the laser to help pick out a general range before using the light to refine the image before readings were taken. This done, we decided to calibrate the machine using a slide of silicon. One problem: it didn't seem to work.

Never mind. We moved onto the IR machine. This threw up its error message straight away. Given the complexity of the machine, we immediately called another beamline scientist. He poked around for quite a while before declaring that an IT 'expert' had changed something (I think it was the computer) and so the optics card had gone and the software needed to be reinstalled.

This did have a silver lining though. We realised that the reason that the Raman wasn't working was because we'd forgotten to pull up a lever to allow the laser to enter. Whoops!

Lesson learnt though, and I'm glad I learnt it earlier.

Over lunch, I met the new placement students starting. It was nice to hear the other projects and sit in the Sun for a bit - again Didcot has the nice weather.


The afternoon, I went down to the lab with my supervisor and she showed me how to load a capillary (a thin tube of borosilicate or quartz with a funnel at one end - I've tried drawing it... I'll let you try). My beamline specialised in powder diffraction experiments, where fine powders of materials are placed in the beam and the way they interact with the light in studied. The capillaries hold these samples.

To give it a go, I start grinding some Copper Nitrate, a salt I'm using for the superconductor, using a pestle and mortar. About halfway through, we noticed it was getting damp, which causes clumps. I soldiered on though and began to place it in a 0.5mm diameter capillary.

Now, behold the toothbrush!

The vibrational power from it shakes the powder down, settling it at the bottom. Or so it should. Being damp, this didn't happen and I ended up breaking the capillary instead.

Capillary 1  Ros 0

Tuesday and I spent the morning reviewing research on Liquid Nitrogen safety (yes, this included making warning posters and I now know why I did so much poster making at Secondary school), heating YBCO (my superconductor) and phase diagrams on YBCO. My conclusion: there's a lot of research about YBCO in really odd situations, but it's quite hard to find the basics sometimes.

Then, I went down into the lab. And I got exciting news! Given 2 of my materials absorb water from the air like crazy,  I get to use the vacuum chamber to prepare samples of them to give my grinding time.

However, for the afternoon, I started preparing a 0.1 to fit inside a 0.3 mm capillary in order to test a glitter substance of which there are limited amounts. It took a while, but I found a pair which would fit.

Capillary 1  Ros 1

To get practice loading first though, I began loading a 0.7 mm Silicon sample. These are used to calibrate the beamline too, so any which are around will be used. With this is mind, I decided to take my time, teasing the Si down with the toothbrush, using an actual blowtorch to cut the funnel off and carefully gluing it into the capillary holder (it appears superglue really is super enough to be used in the beamline). Then, ever so gently, having spent over an hour preparing it, I screwed the holder into the capillary stand to store. The result:

Capillary 2  Ros 1

On Wednesday, I had a nosey into the beamline as Users were coming in today. What I found was people trying to work on fixing a problem (they occasionally happen, even in a synchrotron) and another beamline caused the beam to be switched off briefly.

I started practicing loading more Si 0.7 mm capillaries. This time, I was more careful and began carefully packing the Si into the tube and using the almighty toothbrush. For Si, it should be quite tightly packed, so I soent a while getting it neatly even.

Capillary 3  Ros 1

 Starting again. By 11.40 though,

Capillary 3  Ros 2

HA!

I then started on the glitter, but just as I finished loading it in, my supervisor appeared.

"Did you grind it?"

I managed to get most of it out.

After lunch, I ground it, and spent a while trying get it into the funnel. The mortar though was too heavy and the powder was now dust. Not willing to admit defeat, my supervisor found a pestle and mortar fit for a mouse. Actually, a mouse might find them a little large. They were incredibly adorable, in a way, and reminded me of the bowls in a doll-house.  

Being careful, with the amount of material left, I regounded gently and tried again.

I tried for an hour and a half (most science is fun, I promise!). The issue was the amount of material, as I scraped the mortar clean, even using the stuff on my gloves, to get only 2 mm of sample. My supervisor, though, thought that given we were fitting a 0.1 capillary inside to make it air-tight it should be OK. Was it? Well;

 

Capillary 4  Ros 2

 The manufacturing leaves a ball of glass at the end thicker than the rest. It wouldn't fit to the end.

The last hour I spent in the beamline, whose experiment was up and running. I'm still gathering details on it, as it's running over several days, so I hope to be able to share a proper explanation at some point.

In terms of Me vs. the capillaries, well...

TBC

PS. Talking to another intern at the end of the day: he also used the toothbrush trick. See, it's a valid scientific method.

   (PPS. All pictures from clipart)