In the KB-Binaryapp we saw how much could be learned from just an activity coefficient curve. Here we get a glimpse of what is going on within a ternary mix. The ternary diagrams show which parts of formulation space are very uncomfortable (deep red!) or are rather happy (blue to purple). By moving the mouse you get an instant readout of composition and Gij values.
This app isn't for the faint-hearted. But it shows just how powerful KB can be, and how nice 3D graphics can be. You can move and zoom the view with your mouse. The VR version of the app is awesome as you can fly around the data!
The data fitting will take a few seconds on a typical laptop, so be patient on loading or swapping between examples.
The interactions of three solvents can range cover a vast range of behaviours. There are multiple ways to describe them, but they tend not to provide a unified idea across the whole range. Because KB Integrals are both fundamental and relate to chemical intuition, it makes good sense to use KBIs to analyse what is happening within the solvent mixes. But first you need the data. This used to be hard to obtain. But with modern chembots and with autosampling head-space GC and densitometry, the data are not hard to obtain.
Analysing the data is not so much hard as very fiddly (like so much of thermodynamics). That's why this app exists. Using the theory (and code!) of Dr Enrico Matteoli's group at CNR in Pisa, it is super-easy to go from data to fundamental insight. The key references are provided below. The book chapter is especially recommended as it takes the Gibbs free energies from the papers and converts them to KBI.
This current version takes the Excess Volume and VLE data (both binary and ternary) from the three quoted papers, fits those data to a slightly simplified set of 7 fitting curves (gaining generality and losing slightly on accuracy) then converts them to KBIs. Future versions will allow you to load your own raw datasets.
Use your mouse to move around the 3D world. I am also working on a Virtual Reality version to make it easier to fly through the data.
Acknowledgement and References
I express my warm gratitude to Dr Matteoli who provided much assistance (and excellent code) to help me develop the app.
Here are the key references for those who wish to explore further. Sub references for data on excess volumes can be found in these references.
- Enrico Matteoli, Paolo Gianni and Luciano Lepori, KBIs in Fully Miscible Ternary Systems, Chapter 4 of Paul E Smith, Enrioc Matteoli and John P O'Connell editors, Fluctuation Theory of Solutions, CRC Press 2013
- Luciano Lepori and Enrico Matteoli, Excess Gibbs energies of the ternary system ethanol + tetrahydrofuran + cyclohexane at 298.15K, Fluid Phase Equilibria 134 (1997) 113-131
- P. Gianni, L.Lepori, E.Matteoli, Excess Gibbs energies and volumes of the ternary system chloroform + tetrahydrofuran + cyclohexane at 298.15K, Fluid Phase Equilibria 297 (2010) 52–61
- Enrico Matteoli, Paolo Gianni, and Luciano Lepori, Excess Gibbs Energies of the Ternary System 2-Methoxyethanol + Tetrahydrofuran + Cyclohexane and Other Relevant Binaries at 298.15K, J. Chem. Eng. Data 2010, 55, 5441–5448