Thesis topics in Chemistry (for October 2022)

1. The recovery of critical materials from phosphogypsum from the fertilizer industry
   • Supervisor: Prof. dr hab. inż. Grażyna Zakrzewska-Kołtuniewicz
   • Auxiliary Supervisor: Dr Katarzyna Kiegiel
   • Description: The worldwide production of phosphate fertilizers is mostly based on phosphoric acid produced from phosphorous rocks and leaves huge amounts of phosphogypsum. It contains sometimes significant amounts of REE and other valuable metals. The recovery of these metals along with the processing of phosphogypsum deposited in heaps in many places around the world seems to be a reasonable approach and may contribute to the „urban mining”, which is gaining importance in the era of depleting sources of raw materials. The work will be focused on the recovery of REEs from phosphogypsum and the use of remaining gypsum. Both REEs and natural gypsum are on the 2020 EU’s list of critical raw materials (CRMs).
     The project includes:
     • the determination of phosphogypsum composition (heavy metals including radioactive elements)
     • the development of methods for purifying and for concentrating rare earth elements contained in phosphogypsum stocked in Poland
     • the processing of phosphogypsum to obtain REE concentrate and gypsum matrix
     • the characterization of obtained products
   • Funding: IChTJ Fellowship
2. Active packaging materials with antioxidant properties based on natural and synthetic polymers and obtained with the use of radiation methods
   • Supervisor: Dr hab. inż. Krystyna Anna Cieśla, Prof INCT
   • Description: Food safety and striving to extend the shelf-life of food as well as the protection of the environment are very important issues today. The current leading trends in food packaging are the pursuit of introducing active packaging (films and coatings) with antioxidant or biocidal properties, and the use of biocomposite and bionanocomposite materials obtained on the basis of natural and biodegradable polymers. The technologies that apply ionising radiation (gamma rays or fast electrons) are “clean” and safe methods that reduce the consumption of harmful chemicals and are widely used for polymers modification due to their ability to initiate degradation, cross-linking and grafting. The proposed studies will concern the preparation of a new generation of active packaging materials intended for food (films and coatings). The research will focus on materials with antioxidant activity, but in justified cases, their biocidal potential will also be tested in external laboratory. For the program purpose, commercially available certified films approved for contact with food based on natural and synthetic biodegradable polymers as well as traditional non-degradable polymers will be used. However, new biodegradable materials, including edible ones, will be also synthesized on the basis of natural and synthetic polymers by the doctoral student. This concerns starch:alginate:pectin:PVA:nanocellulose system. The antioxidant/antimicrobial properties of the material will be achieved through grafting of active ingredients of natural origin (plant extracts: essential oils and pure polyphenolic compounds) onto the ready film, or their immobilization during synthesis. Both of these paths will be supported by ionizing radiation. As concerns commercial films, preliminary experiments dealing with grafting the selected active compound (gallic acid) onto several compositions will be carried out, and then the appropriate object(s) for future detailed studies will be chosen. The research will focus both on the optimization of the films’ composition (including possible synergistic effects of various polyphenolic compounds in mixtures), and on the optimization of the methodology of active films’ preparation, in particular of radiation induced grafting. An assessment of the influence of the applied treatment on the functional properties of the film (mechanical, hydrophobic / hydrophilic, thermal, safety for food and effectiveness of their antioxidant/biocidal activity) will be done and related to structural/morphological properties of the materials and the processes taking place under influence of ionising radiation.
   • Funding: IChTJ Fellowship