Author ORCID Identifier
https://orcid.org/0009-0007-4959-163X
Date Available
7-31-2024
Year of Publication
2024
Document Type
Master's Thesis
Degree Name
Master of Science in Chemical Engineering (MSChE)
College
Engineering
Department/School/Program
Chemical and Materials Engineering
Advisor
Dr. Isabel C. Escobar
Abstract
Global water scarcity and quality concerns in the past decade have led to a looming global water crisis. Polymeric membranes have emerged as a potential solution due to their modularity, operational reliability, and wide range of contaminant removal. Polyvinylidene fluoride (PVDF) is often selected as a membrane material for its enhanced chemical resistance, thermal stability, and mechanical strength. However, these membranes often require more complex fabrication methods or support materials to achieve optimum performance. Flat-sheet unsupported PVDF membranes were fabricated via nonsolvent induced phase separation. The influence of solvent, polymer composition, pore forming additives, and casting conditions were explored with respect to membrane properties and performance. The efficacy of environmentally friendly solvents was explored using Rhodisaolv® PolarClean and gammavalerolactone (GVL), which are either bioderived or ecofriendly and reduced/no toxicity compared to traditional petroleum derived solvents, such as N-methyl-2-pyrrolidone (NMP). GVL was unable to dissolve PVDF as a lone solvent, but when mixed into a cosolvent with PolarClean dissolution was observed. Solutions using green solvents were more viscous than those prepared with NMP, which impacted morphology, porosity, and separation performance. The addition of polyvinylpyrrolidone (PVP) as a pore forming additive increased membrane permeability and porosity at higher concentrations; however, a decrease in selectivity was observed. Casting speed was found to have a significant effect on mechanical strength and hydrophobicity. A critical shear rate was identified where permeability and selectivity performance is optimal.
Digital Object Identifier (DOI)
https://doi.org/10.13023/etd.2024.354
Funding Information
The reported research was supported by the National Science Foundation under grant number NSF 2128038. The content is solely the responsibility of the authors and does not necessarily represent the views of the National Science Foundation.
Recommended Citation
Kaplan, Rachel, "EXPLORING THE EFFECT OF CASTING SOLUTION COMPOSITION, ADDITIVES, AND CASTING CONDITIONS ON THE MORPHOLOGY AND SEPARATION PERFORMANCE OF PVDF MEMBRANES" (2024). Theses and Dissertations--Chemical and Materials Engineering. 166.
https://uknowledge.uky.edu/cme_etds/166
