Intermission

Efficient water filtration methods have successfully prevented water-related illnesses and diseases for centuries. Sources such as lakes and rivers, as well as transportation media like underground water pipes, carry many ion contaminants within solution that can be harmful to human health once consumed. Current separation methods for water purification such as distillation, however, necessitate a high energy input, possibly harming the environment by producing carbon emissions when burning fossil fuels. An innovative separation method that does not require phase changes (i.e., vaporization), such as semi-permeable polymer membranes, can be designed to reduce costs of operation and environmental risks. A poly(trifluoroethyl methacrylate-r-oligo(ethyl methyl ether methacrylate)-r-glycidyl methacrylate) [P(TFEMA-OEGMA-GMA)] copolymer was synthesized to function as the active layer in the membranes, which were later prepared using a doctor blade technique. Functionalization can be obtained by submitting copolymer membranes under epoxide ring-opening reactions of glycidyl methacrylate (GMA) repeating unit by using nucleophilic amines, such as 1-(3-aminopropyl)imidazole (API). Factors considered in the study that might have affected the extent and rate of reaction were pH conditions of 9 and 12, as well as concentrations of amine solution of 0.25M and 0.10M, respectively. All reacted membranes were characterized using FTIR by observing the disappearance of a peak at a wavelength of 910cm^-1, which is associated with the epoxide ring. P(TFEMA-OEGMA-GMA) membranes were tested as a possible method of purification by studying diafiltration experiments for the separation of single-ion solutions, considering the rejection of cations in feed solution is due to electrostatic force of repulsion with the membrane’s active layer. In order to determine concentrations of retentate samples as the diafiltration experiment for mixed-ion solutions runs, a planar, three-dimensional calibration curve relating conductivity to the concentration of each ion was preemptively generated for each ion pair, which were chosen based on their differing valencies (CuCl₂ – CoCl₂, KCl – NaCl, KCl – K₂SO₄, and KCl – MgCl₂).