CAF version 2.0

This week has been relatively relaxed and given me some time to focus on midterms and other projects. In the world of the CAF though, we have been focusing on a paper done by Matt and Allison done in 2012 called “Molecular and System Parameters Governing Mass and Charge Transport in Polar Liquids and Electrolytes” whose title is a mouthful to say the least. In a lot of ways this paper continues on the work done before it, using the CAF to more accurately describe the conductivity of several families of solvents (this time being nitriles, thiols, acetates, and ketones), but the interesting aspect of this paper is not its continuation of the tradition CAF research, but the release of the new and improved CAF 2.0. CAF version 2.0 now, instead of just stating that the exponential prefactor is dependent of the dielectric constant which is dependent on temperature, states that the temperature dependence of the dielectric constant can be contained in the quantity N/T or dipole density over temperature. Although this may seem nuanced, this change is significant since it now describes transport (diffusivity) as being dependent on a molecular scale property instead of the abstract dielectric constant.

There are lots of interesting things going on this paper most of which seemed to get covered up by the above point. For example, they attempt to dope TbaTf into nitriles, acyclic carbonate, and thiols, which ended up only working for the nitriles since the thiol and acyclic carbonate solutions could not dissolve the TbaTf fully. They also talk about using the Onsager model of the dielectric constant to describe transport as a theoretical base for their adaptation to the CAF seen above. I also notice they snuck in the use of the pulsed field gradient NMR spin-echo technique to find the diffusion coefficints that keeps emerging in paper after paper that I read.

I am hoping this week to work through exactly how density measurements relate to finding our dipole moments of a given solution, and to maybe even take a few measurements myself.

For the Break- I will be geologing all of reading period up in Duluth at the annual summit of the Institute on Lake Superior Geology (or ILSG for the kids in the know), so I sadly will be away from the lab this week, but fear not, I arrive back at 2am on Sunday which, if I sleep in the lab, gives me 48h of pure uninterrupted lab time.


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