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dc.rights.licenseRestricted to current Rensselaer faculty, staff and students. Access inquiries may be directed to the Rensselaer Libraries.
dc.contributorPlawsky, Joel L., 1957-
dc.contributorUnderhill, Patrick T.
dc.contributorLinhardt, Robert J.
dc.contributorKilduff, James
dc.contributorDinolfo, Peter
dc.contributor.authorKeating, John J., IV
dc.date.accessioned2021-11-03T09:22:16Z
dc.date.available2021-11-03T09:22:16Z
dc.date.created2021-02-22T15:32:45Z
dc.date.issued2020-08
dc.identifier.urihttps://hdl.handle.net/20.500.13015/2623
dc.descriptionAugust 2020
dc.descriptionSchool of Engineering
dc.description.abstractCommercial regenerated cellulose membranes with 1 kDa molecular weight cutoff (MWCO) were grafted with chiral L-proline-copper complexes to form chiral ligand exchange membranes. The resulting membranes were evaluated in single component diffusion and pressure-driven experiments with D or L-Phenylalanine (Phe), exhibiting higher permeability for D-Phe compared with L-Phe. The ligand exchange membranes were challenged with an equimolar racemic mixture of D,L-Phe under pressure-driven filtration. These ligand exchange membranes completely fractionated the enantiomers. It may be possible to increase membrane performance using these novel ligand exchange membranes by amplifying the number of functional groups in a polymer brush.
dc.description.abstractA kinetic model based on the reaction rate equations for describing the Activators Regenerated by Electron Transfer (ARGET) - Atom Transfer Radical Polymerization (ATRP) reaction mechanism provided evidence that the molar ratios of transition metal catalyst to initiator and reducing agent to catalyst are critical parameters, with optimal values on the order of 0.1:1 and 10:1, respectively. The model also predicted an optimal molar ratio of reducing agent to initiator of 1:1 and that adding a sacrificial initiator was necessary to prevent loss of control on the polymerization.
dc.description.abstractA novel surface modification technique was proposed for grafting from commercial PES nanofiltration membranes comprising a combination of atmospheric pressure plasma treatment followed by Activators Regenerated by Electron Transfer (ARGET) Atom Transfer Radical Polymerization (ATRP). The grafted membranes showed degree of grafting increases of 28, 94, and 270% for methyl methacrylate (C1), hexyl methacrylate (C6), and stearyl methacrylate (C18), respectively. Molecular dynamics simulations reinforced the morphology observed experimentally for PES grafted with C18 via Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM).
dc.description.abstractIn the first study of its kind, mean radical lifetimes and fluctuations in radical lifetime were shown to decrease with conversion and polydispersity index for the ATRP polymerization of both methyl methacrylate and styrene using kMC models. An investigation of radical lifetimes in both ATRP and conventional free-radical polymerizations was performed. The lifetimes of the radicals were shown to be thousands of times longer in conventional free-radical polymerization compared with ATRP. A new perspective on the ATRP mechanism was offered through the analysis of mean radical lifetimes and fluctuations in radical lifetime. Reduction in such fluctuations aids in keeping the polydispersity index low. The results of the kMC models were complemented with deterministic models, such as the reaction rate equations and the method of moments, to investigate several facets of these polymerization reactions. The deterministic and stochastic models were validated against experimental data.
dc.description.abstractDeterministic and stochastic models of the bulk free-radical polymerization of methyl methacrylate through the gel regime are presented using the method of moments and kinetic Monte Carlo (kMC) simulations, respectively. Two chain length dependent termination models were compared: the methods of Karlsson and Johnston-Hall. A novel calibration methodology produced scale factors which bring about agreement between the models. The kMC Johnston-Hall model showed too strong a chain length dependent termination effect while the method of moments simulations showed too weak a chain length dependence. The Karlsson model was the most robust chain length dependent termination model investigated.
dc.description.abstractAtmospheric pressure plasma induced graft polymerization, an uncontrolled polymerization technique, of two monomers was attempted from the surface of commercial poly(ether sulfone) (PES) membranes: hexyl methacrylate (C6) and stearyl methacrylate (C18). It was shown that water is ineffective at removing physically adsorbed material via an Attenuated Total Reflectance – Fourier Transform Infrared Spectroscopy (ATR-FTIR) study. Ethanol was herein experimentally verified to remove such physically adsorbed species and eliminate “false – positive” conclusions regarding the grafting of these monomers.
dc.description.abstractExperimental studies on the fundamentals of surface grafting reactions with commercial membranes are presented. Both controlled and uncontrolled grafting methods have been studied. The polymerization mechanisms were investigated in detail and kinetic models were developed. Kinetic models were applied to study the surface grafting reactions and to obtain new insights into controlled and uncontrolled polymerization processes in general. Both deterministic and stochastic models were employed and compared where appropriate.
dc.language.isoENG
dc.publisherRensselaer Polytechnic Institute, Troy, NY
dc.relation.ispartofRensselaer Theses and Dissertations Online Collection
dc.subjectChemical engineering
dc.titleDeterministic and stochastic modeling of polymerization kinetics with membrane applications
dc.typeElectronic thesis
dc.typeThesis
dc.digitool.pid180363
dc.digitool.pid180364
dc.digitool.pid180365
dc.rights.holderThis electronic version is a licensed copy owned by Rensselaer Polytechnic Institute, Troy, NY. Copyright of original work retained by author.
dc.description.degreePhD
dc.relation.departmentDept. of Chemical and Biological Engineering


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