Z. Sarwar “Formation, characterization, and applications of poly(ether-block-amide) structures for separation processes” doctoral dissertation defence

Author, Institution: Zahid Sarwar, Kaunas University of Technology

Science area, field of science: Technological Sciences, Chemical Engineering, T005

Scientific Supervisor:
Prof. Dr. Dainius Martuzevičius (Kaunas University of Technology, Technological Sciences, Chemical Engineering, T005), 2018-2021
Prof. Dr. Hab. Juozas Vidas Gražulevičius (Kaunas University of Technology, Technological Sciences, Chemical Engineering, T005), 2017-2018

Dissertation Defense Board of Chemical Engineering Science Field:
Prof. Dr. Kęstutis Baltakys (Kaunas University of Technology, Technological Sciences, Chemical Engineering, T005) – chairperson
Prof. Dr. Linas Kliučininkas  (Kaunas University of Technology, Technological Sciences, Environmental Engineering, T004)
Dr. Thomas Mayer-Gall (Deutsches Textilforschungszentrum Nord-West GmbH, Natural Sciences, Chemistry, N003)
Prof. Dr. Ramunė Rutkaitė (Kaunas University of Technology, Technological Sciences, Chemical Engineering, T005)
Prof. Dr. Jaunius Urbonavičius (Vilnius Gediminas Technical University, Technological Sciences, Chemical Engineering, T005).

The doctoral dissertation is available at the library of Kaunas University of Technology (K. Donelaičio g. 20, Kaunas).

Annotation:

The increasing awareness about the environmental issues worldwide has enhanced the applications of separation methods, including the utilization of polymeric membranes. Poly(ether-block-amide), often abbreviated as PEBA, is among the most promising novel polymers for these applications. It is a copolymer of polyamide and polyether segments, having a higher mechanical strength (due to the hard polyamide segment) whereas flexibility is due soft polyether segment. These properties make it an interesting candidate as a matrix to support functional nanofillers in environmental applications. In the first phase of the research, fibrous membranes of PEBA were developed by melt and solution electrospinning techniques. The effects of process parameters of both electrospinning techniques on resultant fiber diameters and morphology were researched. In the second phase, a novel approach was utilized to prepare fibrous PEBA nanocomposite membranes while devoting a special attention to achieving uniform nanomaterial dispersion. For that purpose, extrusion process was used to prepare nanocomposite filaments in the presence of 0.2 wt.% of paraffin liquid (adhesive layer) and 0.05–0.4 wt.% of graphene (GA). The prepared filaments were spun into fibrous membranes using melt electrospinning as environment friendly additive manufacturing technology. The potential application of the fabricated fibrous membranes in the clean-up of oil spills was studied. In the third phase graphene oxide (GO) particles were embedded to PEBA melt electrospun fibers. Such composite matrix was demonstrated for the adsorption of a cationic dye from aqueous medium. Various amounts of GO (from 0.5 to 2.0%) were mixed into pure PEBA and electrospun by melt electrospinning obtaining micro fibrous matrixes. In the fourth phase, dense nanocomposite membranes of GA/PEBA were fabricated by solution casting technique. The granules of PEBA were mixed with various concentrations of GA in the presence of paraffin liquid by using extrusion process. These fabricated membranes were evaluated for CO₂/CH₄ selectivity at low and high temperatures (25 and 55 °C) at a constant feeding pressure (2 bar) using a test rig built especially for that purpose.