New Week a New Protocol


This week the lab was considerably quieter. With our undergrad still sick and my mentor working on a manuscript at home I had a lot of time in the lab by myself. I continued to work on the old protocol and start writing and refining my abstract. I continue to look at the same papers that I have read about ATPE and try to find new ones that use different molecular weights of the polymers that form the two phases. I have gotten to a place where I have almost mastered the oxidation protocol using TCCA to separate semi-metallic SWCNTs from metallic SWCNTs. It’s weird that my separation works better after incubating over night so I will be looking into why this may be by changing the centrifugation next week.

All SWCNTs are in the top phase before the addition of TCCA.
After the addition of TCCA the semi-metallic SWCNTs are found in the top phase. While the bottom phase has no clear properties.
After waiting overnight there is a clear separation of phases with an aggregate at the interphase.
Semi-metallic SWCNTs rich top phase is in the cuvette on the left while metallic SWCNTs rich bottom phase is in the cuvette on the right.


I run my cuvettes containing samples in the spectroscopy machine. During the weekly meeting we went over my results. I am now getting a much better sample of semi-metallics than before. The absorbance, however, looks off. So next week I will be working on getting a clearer bottom phase, currently it looks cloudy. I also will be looking into why the separation works better if I let the eppendorf tube incubate over night.

Reading the data as it is collected with the NS1 machine.


I’ve mentioned that I was using different molecular weights which resulted in poor separation. It turns out that the new molecular weights are supposed to be used with DNA wrapped SWCNTs rather than surfactant wrapped SWCNTs. Knowing this, I was given a new protocol to use with the molecular weights. I have only run one trial with this new protocol. It uses a VERY small amount of substances because DNA is much more expensive than the surfactants that I had been using.

First attempt of separating DNA wrapped SWCNTs using Dx 250 and PEG 1.5 following a new procedure.

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