Synthesis and characterization of inorganic-organic hybrid silsesquioxanes-based porous networks towards adsorption processes
Author
Ballarini, Barbara
Term
4. Term
Education
Publication year
2022
Submitted on
2022-06-09
Pages
60
Abstract
This thesis reports the development of porous polymers built from silsesquioxanes (SQs), small silicon–oxygen cage-like units that can be linked to organic molecules. The work followed two main steps: SQ precursors were prepared via a sol-gel process, and the organic building block TTSBI was synthesized by a cyclization reaction. The organic and inorganic parts were then cross-linked using the Schotten-Baumann reaction and Michael addition. The resulting structures were confirmed by 13C and 1H nuclear magnetic resonance (NMR) and attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectroscopy. Three SQ–organic hybrids were obtained—0.01TTSBI, T8TTSBI, and T8SEBCL—with different structures and compositions. 0.01TTSBI is a random SQ network covalently bonded to TTSBI. T8TTSBI and T8SEBCL both share a cubic T8 silsesquioxane framework; T8TTSBI is combined with oxidized TTSBI, whereas T8SEBCL is combined with sebacoyl chloride. These materials were tested as adsorbents, meaning they capture dyes and a heavy metal ion on their surfaces. The results showed that 0.01TTSBI was the most versatile, as it could adsorb all the tested species in varying amounts. Overall, adsorption was dominated by chemisorption (chemical bonding), with 0.01TTSBI also showing contributions from physisorption (weaker physical interactions).
Denne afhandling beskriver udviklingen af porøse polymerer baseret på silsesquioxaner (SQ), som er små silicium–oxygen enheder med bur-lignende struktur, der kan kobles til organiske molekyler. Arbejdet foregik i to hovedtrin: Forstadierne blev fremstillet ved en sol-gel-proces for SQ’erne, mens den organiske byggesten TTSBI blev syntetiseret via en cykliseringsreaktion. Derefter blev den organiske og den uorganiske del krydsbundet ved hjælp af Schotten-Baumann-reaktionen og Michael-tilsætning. Strukturerne blev bekræftet med 13C- og 1H-NMR samt ATR-FTIR-spektroskopi. Der blev fremstillet tre forskellige hybridmaterialer: 0.01TTSBI, T8TTSBI og T8SEBCL, som varierer i struktur og sammensætning. 0.01TTSBI udgør et tilfældigt SQ-netværk kovalent bundet til TTSBI. T8TTSBI og T8SEBCL bygger begge på en kubisk T8-silsesquioxan-struktur; i T8TTSBI er T8 kombineret med oxideret TTSBI, mens T8SEBCL er kombineret med sebacoylchlorid. Materialerne blev undersøgt som adsorbenter, dvs. overflader der kan binde farvestoffer og en tungmetalion fra opløsning. Resultaterne viste, at 0.01TTSBI var mest alsidig, fordi det kunne adsorbere alle de testede stoffer i forskellige mængder. Samlet set tyder data på, at adsorptionen overvejende sker ved kemisorption (kemiske bindinger), mens 0.01TTSBI også udviser fysisorption (svagere, fysiske interaktioner).
[This apstract has been rewritten with the help of AI based on the project's original abstract]
Keywords