Polielektrolitni polihipe hidrogeli za sanacijo onesnaženih voda : doktorska disertacija

slovenian

doktorska dela

2021

conjugated materials   high internal phase emulsions   polyelectrolytes   porous polymers   Sonogashira-Hagihara cross coupling reaction   water pollution

Univerza v Mariboru, Fakulteta za kemijo in kemijsko tehnologijo

Water is essential for life. Water pollution is one of the most serious ecological threats we face today. In this dissertation thesis, highly porous polymers are investigated for efficient removal of various pollutants from water (such as ionic organic dyes, heavy metals or endocrine disruptors) by adsorption or photocatalytic degradation. %%In this dissertation, highly porous monoliths or beads (mainly polyHIPE materials) based on 2-acrylamido-2-methylpropanesulfonic acid (AMPS), (3-acrylamidopropyl) trimethylammonium chloride (AMPTMA) and N-vinylformamide (NVF) are studied. The influence of the composition and mixing of the HIPEs on the porous morphology of the final amphoteric polyHIPE monoliths, their distribution of polyion groups (-SO3 or -NR3%) within the monolith and their efficiency in removing organic dyes from water were investigated. The aim of this research was to have both positive and negative ionic groups within the porous morphology in the same monolith, so that both cationic and anionic organic dyes are adsorbed from the aqueous solution simultaneously. Porous polyamphoteric monoliths showed excellent results in the simultaneous adsorption of both cationic (methylene blue) and anionic (erythrosine) dyes from water. Porous monolithic adsorbents were prepared using a simple approach to mixing HIPE and have a polymer backbone of different polycationic and polyanionic networks and showed exceptional adsorption abilities. For the polyHIPE monoliths prepared with N-vinyl formamide, we investigated the influence of the crosslinker and hydrolysis conditions on the conversion of the formamide groups to polyamine. A high conversion to the primary amine was confirmed with almost 10 mmol of groups per gram of polyHIPE material. The synthesized polyamine-polyHIPE exhibits excellent adsorption and absorption properties, about 100 g of water per gram of its dry mass. The polyamine-polyHIPE adsorbent was tested for the removal of Cu2+ ions from water. After 1 hour, the material adsorbed 43% of the initial concentration of Cu2+ ions. %%Polyelectrolyte polyHIPE materials in the form of beads were prepared from multiple emulsions via sedimentation polymerization. The beads were prepared based on AMPS or AMPTMA ionic monomers in combination with acrylamide (AAm) in different molar ratios. We investigated the influence of the compositions of the multiple emulsions (type and proportion of monomers, crosslinker and initiator) on the shape and morphology of the beads. The combination of polyelectrolyte character and porous structure of polyHIPE beads resulted in a high degree of swelling in water, as they reached the equilibrium value of water absorption after only 15 seconds. As the content of ionic monomers increased, the equilibrium value increased and so did the water uptake. The maximum amount of adsorbed water for PAMPS-based polyHIPE beads is about 21-38 (g%g-1), while the PAMPTMA-based beads are 25-43 (g/g). PAMPTMA-based polyHIPE beads were also tested as desiccants for drying organic solvents, such as toluene, dichloromethane, N,N-dimethylformamide and tetrahydrofuran. The polyelectrolyte polyHIPE beads were able to remove between 60 and 95 % of the initial water in organic solvents in less than one hour. %The second part of the PhD studies the synthesis of %-conjugated polyHIPE materials with Sonogashira-Hagihara cross-coupling reaction based on poly(aryleneethynylene) (PAE) from various substituted nonionic monomers (1,4-diiodobenzene, 1,4-diiodo-2,5-dimetoxybenzene, 2,6-diiodo-4-nitrophenol and 2,5-diiodohydroquinone) and ionic monomer (1,4-diiodo-2,5-bis(3-sulfonatopropoxy)benzene). PAE-based polyHIPEs have semiconducting properties at the expense of the %-conjugated backbone, which enables them to photocatalytically degrade dissolved pollutants in water. PAE-polyHIPE have been investigated as photocatalysts for the degradation of various bisphenols under visible light. PAE-polyHIPEs based on 1,4-diiodobenzene achieved

07.08.2023