sinteza in strukturna karakterizacija
David Dragan (Author), Anton Meden (Mentor)

Abstract

Zeoliti so predstavniki kristaliničnih mikroporoznih materialov, ki jih najpogosteje pripravimo s hidrotermalno sintezo iz reakcijskih gelov, ki vsebujejo vir aluminija, silicija, topilo in strukturne usmerjevalce. Zaradi svoje značilne kemijske sestave, možnosti dodatne funkcionalizacije in urejenega sistema por točno določenih oblik in velikosti, se zeoliti uporabljajo kot učinkoviti absorbenti in heterogeni katalizatorji v pomembnih industrijskih procesih. Poleg že dobro uveljavljene uporabe zeolitov v predelavi nafte, proizvodnji kemikalij, odstranjevanju NOx, SOx, N2, O2, vode iz zraka so zeoliti pokazali odlične lastnosti tudi na področju pridobivanja in shranjevanja virov energije ter na področju tehnologij selektivnega zajema in pretvorbe CO2 v goriva. V diplomski nalogi sem se osredotočil na preučevanje možnosti uporabe kubičnega zeolita P kot sorbenta za kasnejšo uporabo pri odstranjevanju plinov CO2 iz onesnaženega zraka. Namen diplomske naloge je bil preučiti sintezne parametre (čas in temperatura kristalizacije, pH), vpliv surfaktantov in Si/Al razmerja na velikost, obliko in aglomeriranost delcev zeolita P. Izbranemu sinteznemu postopku za sintezo zeolita P sem določil optimalne kristalizacijske pogoje in molsko razmerje. Vzorci so bili karakterizirani s pomočjo rentgenske praškovne difrakcije (XRPD), vrstične elektronske mikroskopije (SEM), termogravimetrične analize (TG), elementne analize (EDS), dinamičnega sipanja svetlobe (DLS) in CHN analize. S spreminjanem Si/Al razmerja sem uspel oz. sem bolje vplival na velikost in aglomeriranost delcev zeolita P kot z uporabo različnih surfaktantov. Pripravil sem fazno čist kubičen zeolit P (zeolit P1) z ocenjeno velikostjo osnovnih delcev približno 17 nm, ki so se nadalje povezovali v aglomerate različnih velikosti od 300 – 500 nm.

Keywords

materiali;zeoliti;zeolit P;nanodelci;aluminosilikati;hidrotermalna sinteza;surfaktanti;diplomske naloge;

Data

Language: Slovenian
Year of publishing:
Typology: 2.11 - Undergraduate Thesis
Organization: UL FKKT - Faculty of Chemistry and Chemical Technology
Publisher: [D. Dragan]
UDC: 549.6(043.2)
COBISS: 1538523075 Link will open in a new window
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Downloads: 227
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Other data

Secondary language: English
Secondary title: Influence of synthesis parameters on the size of zeolite P crystals: synthesis and structural characterization
Secondary abstract: Zeolites are a type of crystalline microporous materials. They are commonly prepared by hydrothermal synthesis from reaction gel containing aluminium and silicon source, a solvent and structure directing agents. Zeolites are used as effective absorbents and heterogeneous catalysts in various industrial processes due to their characteristic chemical composition, possibility of additionally functionalisation and ordered pore system of specifically defined shapes and size. The use of zeolites in oil refinery, chemical production and removal of NOX, SOX, N2, O2 and humidity from air is as well established. Furthermore, zeolites have proved successful in energy recovery and storage and selective capture and conversion of CO2 into fuels. This bachelor thesis focuses on the use of cubic zeolite P as potential sorbent for later removal of CO2 from polluted air. The aim of this thesis was to study synthesis parameters (crystallisation time and temperature, pH), influence of surfactants and Si/Al molar ratio on size, shape and agglomeration of zeolite P particles. Additionally, the optimal crystallisation conditions and molar ratio for zeolite P synthesis were determined. The samples were characterised using X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), thermogravimetric analysis (TG), energy-dispersive X-ray spectroscopy (EDX), dynamic light scattering (DLS) and CHN analysis. To conclude, this study was able to show an increased modification on the size and agglomeration of zeolite P particles by changing Si/Al molar ratio compared to use of surfactants. Phase-pure cubic zeolites P with size of particles 17 nm were agglomerated in various sizes from 300 - 500 nm.
Secondary keywords: zeolite P;nanoparticles;aluminosilicates;hydrothermal synthesis;surfactants;
Type (COBISS): Bachelor thesis/paper
Study programme: 1000374
Thesis comment: Univ. v Ljubljani, Fak. za kemijo in kemijsko tehnologijo, VSŠ Kemijska tehnologija
Pages: 43 str.
ID: 11400514