The research activity focused on the design, synthesis and characterization of porous organic and hybrid materials. Porous materials for selective gas adsorption and storage. Tailored porous organic frameworks bearing different functional groups have been investigated via gas adsorption analyses and in situ spectroscopic techniques to understand the interaction between the guest phase and the primary adsorption sites installed on pore walls. Specifically, aliphatic amines interact strongly with carbon dioxide molecules resulting in an isosteric heat of adsorption as high as 54 kJ/mol at low loading and this close-contact interaction has been characterized with 2D heterocorrelated NMR sppectroscopy. Hyper.crosslinked polymers and porous organic frameworks have been synthetized and their performance towards high pressure (up to 180 bar) methane adsorption have been evaluated to assess their potential applications in adsorbed natural gas technology (ANG). During a period at Bernal institute (Limerick, Ireland) under the supervision of Prof. M. J. Zaworotko, I developed novel switching metal-organic frameworks that display guest-induced phase transitions between close phases and a porous open phase. During the close to open phase transitions the coordination sphere of the zinc cations inside the structures changes from a square pyramidal to a tetrahedral geometry. Moreover, the threshold pressure for gas adsorption can be manipulated through a mixed-linker approach. These materials are currently investigated for applications in gas storage and separation. Metal-organic frameworks with intrinsic dynamics. Metal organic frameworks built up with rigid aliphatic linkers have been developed and their adsorptive and thermal properties fully characterized. These materials display ultra-fast rotational dynamic even at very low temperature. An in-depth solid state NMR study has been conducted to understand the fast rotation of the organic strut and the influence of guest species hosted inside the pores on its dynamic. Organic and hybrid materials for photonic applications. Emitting porous aromatic frameworks (ePAFs) nanoparticles containing highly fluorescent diphenylanthracene moieties have been developed. This materials display high photoluminescence quantum yield and a fast exciton diffusion inside the amorphous framework. When these nanoparticles are suspended in a solution of a suitable sensitizer the mixture display highly efficient sensitized triplet-triplet annihilation up-conversion with quantum yield up to 15 %. Moreover, PAFs with integrated sensitizers (i-ePAFs) display sensitized up-conversion working as an autonomous nanodevice. Metal-organic frameworks with diphenylanthracene units and zirconium oxo-hydroxo clusters have been developed and their luminescence and radioluminescence have been characterized. These nanocrystals have been embedded in polymeric matrixes to generate efficient and innovative scintillating materials with fast response for x-ray and gamma-ray detection.

L'attività di ricerca si è occupata della progettazione, sintesi e caratterizzazione di materiali porosi. Diverse linee di ricerca sono state perseguite. Materiali porosi per l'assorbimento selettivo e lo stoccaggio di gas. Le proprietà di una serie di polimeri porosi organici sono state studiate attraverso misure di assorbimento di gas e misure di risonanza magnetica nucleare dello stato solido in presenza di una fase gassosa per comprendere la natura delle interazioni tra le molecole ospiti e le pareti dei canali. In particolare, si è verificata l'elevata energia di interazione tra le molecole di anidride carbonica e gruppi amminici alifatici che genera un'efficiente trasferimento di magnetizzazione tra gli idrogeni del gruppo amminico e il carbonio dell'anidride carbonica. Polimeri iper-reticolati porosi e polimeri organici porosi sono stati studiati mediante assorbimento di metano ad alta pressione (fino a 180 bar) per possibili applicazioni per lo stoccaggio di gas naturale in presenza di reticoli porosi (ANG). Durante il periodo all'estero presso il Bernal Institute sotto la supervisione del Prof. M.J. Zaworotko mi sono occupato dello sviluppo di una serie di framework metallo-organici che presentano flessibilità strutturale. In presenza di un opportuno gas o vapore i reticoli sintetizzati danno luogo a una transizione di fase tra una fase compatta e una fase porosa in maniera repentina. Questo meccanismo è attualmente molto studiato per le possibili applicazioni nell'ambito dello stoccaggio e separazione dei gas. Reticoli metallo-organici contenenti rotori molecolari. Due nuovi reticoli porosi metallo-organici sono stati sviluppati e le loro proprietà di assorbimento e termiche sono state caratterizzate. Inoltre, i due sistemi contengono un rotore molecolare molto mobile anche alle basse temperature come dimostrato da esperimenti di risonanza magnetica nucleare dello stato solido. Materiali porosi per applicazioni nella fotonica. Sono stati sintetizzati alcuni materiali organici covalenti contenenti difenilantracene. Questi campioni presentano elevata resa quantica di fotoluminescenza. In dispersione e in presenza di un sensibilizzatore opportuno questi materiali danno vita ad un fenomeno di up-conversion dovuto all'annichilazione di tripletto con efficienze fino al 15 %. Inoltre, legando chimicamente il sensibilizzatore al reticolo poroso è possibile ottenere dei sistemi per up-conversion autonomi. Infine, nanocristalli di reticoli metallo-organici porosi sono stati cresciuti e le loro proprietà di foto- e radioluminescenza sono state investigate approfonditamente. Inoltre, questi cristalli, dispersi all'interno di una matrice polimerica, sono stai utilizzati per sviluppare degli innovativi scintillatori ibridi per la rivelazione di raggi x e gamma.

(2020). Functional Porous Materials: Tailored Adsorption Properties, Flexibility and Advanced Optical Applications. (Tesi di dottorato, Università degli Studi di Milano-Bicocca, 2020).

Functional Porous Materials: Tailored Adsorption Properties, Flexibility and Advanced Optical Applications

PEREGO, JACOPO
2020

Abstract

The research activity focused on the design, synthesis and characterization of porous organic and hybrid materials. Porous materials for selective gas adsorption and storage. Tailored porous organic frameworks bearing different functional groups have been investigated via gas adsorption analyses and in situ spectroscopic techniques to understand the interaction between the guest phase and the primary adsorption sites installed on pore walls. Specifically, aliphatic amines interact strongly with carbon dioxide molecules resulting in an isosteric heat of adsorption as high as 54 kJ/mol at low loading and this close-contact interaction has been characterized with 2D heterocorrelated NMR sppectroscopy. Hyper.crosslinked polymers and porous organic frameworks have been synthetized and their performance towards high pressure (up to 180 bar) methane adsorption have been evaluated to assess their potential applications in adsorbed natural gas technology (ANG). During a period at Bernal institute (Limerick, Ireland) under the supervision of Prof. M. J. Zaworotko, I developed novel switching metal-organic frameworks that display guest-induced phase transitions between close phases and a porous open phase. During the close to open phase transitions the coordination sphere of the zinc cations inside the structures changes from a square pyramidal to a tetrahedral geometry. Moreover, the threshold pressure for gas adsorption can be manipulated through a mixed-linker approach. These materials are currently investigated for applications in gas storage and separation. Metal-organic frameworks with intrinsic dynamics. Metal organic frameworks built up with rigid aliphatic linkers have been developed and their adsorptive and thermal properties fully characterized. These materials display ultra-fast rotational dynamic even at very low temperature. An in-depth solid state NMR study has been conducted to understand the fast rotation of the organic strut and the influence of guest species hosted inside the pores on its dynamic. Organic and hybrid materials for photonic applications. Emitting porous aromatic frameworks (ePAFs) nanoparticles containing highly fluorescent diphenylanthracene moieties have been developed. This materials display high photoluminescence quantum yield and a fast exciton diffusion inside the amorphous framework. When these nanoparticles are suspended in a solution of a suitable sensitizer the mixture display highly efficient sensitized triplet-triplet annihilation up-conversion with quantum yield up to 15 %. Moreover, PAFs with integrated sensitizers (i-ePAFs) display sensitized up-conversion working as an autonomous nanodevice. Metal-organic frameworks with diphenylanthracene units and zirconium oxo-hydroxo clusters have been developed and their luminescence and radioluminescence have been characterized. These nanocrystals have been embedded in polymeric matrixes to generate efficient and innovative scintillating materials with fast response for x-ray and gamma-ray detection.
COMOTTI, ANGIOLINA
Polimeri porosi; assorbimento di gas; MOF flessibili; Porosi luminescenti; rotori molecolari
Porous polymers; gas adsorption; Flexible MOFs; Luminescent material; rotori molecolari
CHIM/04 - CHIMICA INDUSTRIALE
English
21-feb-2020
SCIENZA E NANOTECNOLOGIA DEI MATERIALI
32
2018/2019
open
(2020). Functional Porous Materials: Tailored Adsorption Properties, Flexibility and Advanced Optical Applications. (Tesi di dottorato, Università degli Studi di Milano-Bicocca, 2020).
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/263593
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