Hossain, Mohammad Zahid.
A new lattice fluid equation of state for associated CO₂ + polymer and CO₂ + ionic liquid systems.
Degree: PhD, Chemical and Biomolecular Engineering, 2014, Georgia Tech
The phase behavior of CO2 + polymer systems is of interest in polymer synthesis, flue and natural gas processing, polymer foam and nanoparticle processing, and drug delivery. Theoretical and experimental evidence suggests that CO2 is able to interact with electron donating functional groups in polymers to form weak Lewis acid – base or EDA (Electron Donor Acceptor) complexes. These complexes can have a significant effect on the phase behavior of associated CO2 + polymer systems. In spite of this, however, the phase equilibria of only a few associated CO2 + polymer systems have been measured. Some success in modeling the phase behavior of polymer solutions has been achieved by various versions of the Statistical Association Fluid Theory (SAFT), as well as by several Lattice Models. However, many of these models incorporate two to four adjustable parameters that often depend on temperature (T), pressure (P), and/or molecular weight (MW). As a result, a large amount of experimental data is required to apply these models. The goal of the present work was therefore to develop a new thermodynamic model for associating systems that would include no more than two temperature-independent adjustable parameters. The new model presented in this work is based on the Guggenheim-Huggins-Miller lattice and includes complex formation in the development of the partition function.
The EOS obtained from the resulting partition function includes two mixture parameters – the enthalpy of association or complex formation and a reference value of the equilibrium constant for complex formation . Most importantly, can be obtained from in situ Attenuated Total Reflection Fourier Transform Infrared (ATR – FTIR) measurements. This work therefore demonstrates the use of ATR – FTIR spectra to obtain molecular level information regarding the interaction of CO2 and electron donating functional groups in polymers. Unlike other studies, this work uses the bending vibration of CO2 to estimate the enthalpies of association ( ) of CO2 + polymer systems. Values of were directly incorporated in the new model and were found to lie between -7 and -12 kJ/mol for the systems investigated in this work. They increased (i.e. became more negative) in the order: CO2 + PS-co-PMMA < CO2 + PMMA <CO2 + PBMA < CO2 + PSF < CO2 + PVAc < CO2 + EVA40 < CO2 + PEG.
Values of the second parameter in the new EOS ( ) were obtained by fitting solubility data at one temperature. Both and were found to be temperature independent. The application of the new EOS was demonstrated by calculating the solubility (sorption) of CO2 in polymers, the extent of swelling of polymers due to CO2, and the solubility of polymers in CO2 (cloud points). Both sorption and cloud point behavior in CO2 + polymer systems could be calculated using a single value of for each binary system.
Ionic Liquids (ILs) can also incorporate electron donating functional groups in their structure. Evidence for the interaction of such ILs with CO2 can be found in the large values of the enthalpies of…
Advisors/Committee Members: Teja, Amyn S. (advisor), Koros, William J. (committee member), Ludovice, Peter J. (committee member), Bucknall, David (committee member), Jeter, Sheldon M. (committee member).
Subjects/Keywords: ALF EOS; Association; Specific interaction; Lewis acid-base interaction; Lattice model; CO₂ - polymer systems; CO₂ - IL systems; Molten salt; Rough hard sphere theory; Thermal conductivity
…x29; swelling of PVAc due to CO2
calculated using the ALF EOS with K 0 = 0.10 and H a = 9.3… …lines are calculated using the ALF
EOS with binary parameters from Table 3.4 and points… …CO2 in these ILs. The ALF EOS was
therefore extended to CO2 + IL systems using the enthalpy… …Table 5.1
Characteristic Constants of the ALF and SL Equations for Pure Components
109… …kJ mol-1.
Lines represent calculated values using ALF model  and the points…
to Zotero / EndNote / Reference
APA (6th Edition):
Hossain, M. Z. (2014). A new lattice fluid equation of state for associated CO₂ + polymer and CO₂ + ionic liquid systems. (Doctoral Dissertation). Georgia Tech. Retrieved from http://hdl.handle.net/1853/53475
Chicago Manual of Style (16th Edition):
Hossain, Mohammad Zahid. “A new lattice fluid equation of state for associated CO₂ + polymer and CO₂ + ionic liquid systems.” 2014. Doctoral Dissertation, Georgia Tech. Accessed October 17, 2019.
MLA Handbook (7th Edition):
Hossain, Mohammad Zahid. “A new lattice fluid equation of state for associated CO₂ + polymer and CO₂ + ionic liquid systems.” 2014. Web. 17 Oct 2019.
Hossain MZ. A new lattice fluid equation of state for associated CO₂ + polymer and CO₂ + ionic liquid systems. [Internet] [Doctoral dissertation]. Georgia Tech; 2014. [cited 2019 Oct 17].
Available from: http://hdl.handle.net/1853/53475.
Council of Science Editors:
Hossain MZ. A new lattice fluid equation of state for associated CO₂ + polymer and CO₂ + ionic liquid systems. [Doctoral Dissertation]. Georgia Tech; 2014. Available from: http://hdl.handle.net/1853/53475