Sinteza in karakterizacija mezoporoznih SiO$_2$ materialov z dodatki za uravnavanje velikosti por

Devjak, Anže (author), Perdih, Franc (mentor), Nadrah, Peter (comentor)

Magistrska naloga se osredotoča na sintezo in karakterizacijo mezoporoznih SiO$_2$ materialov z dodatki za uravnavanje velikosti por. Mezoporozni materiali so zaradi svojih posebnih lastnosti, kot sta velika specifična površina in urejena struktura por, primerni za različne aplikacije, kot so kataliza, adsorpcija, dostava zdravilnih učinkovin in uporaba v senzoriki. Glavni cilj raziskave je bil proučiti vpliv različnih dodatkov, kot so 1,3,5-trimetilbenzen (TMB) in soli maščobnih kislin z različno dolžino alkilnih verig, na velikost in urejenost por. Materiali so bili sintetizirani s sol-gel metodo ob prisotnosti površinsko aktivne snovi, ki je služila kot strukturo usmerjajoča snov. Pri raziskavi smo spreminjali sintezne pogoje, kot sta temperatura in pH reakcijske mešanice ter vrsto in koncentracijo dodatkov za uravnavanje velikosti por, kot so TMB in soli maščobnih kislin z različno dolžino alkilne verige. Poleg spreminjanja sinteznih pogojev smo proučili tudi vpliv dodatne posintezne hidrotermalne obdelave nekaterih izbranih vzorcev ter vpliv različnih tehnik odstranitve strukturo usmerjajoče snovi. Proučili smo vpliv ekstrakcije, termične obdelave (kalcinacije) ter kombinacije obeh tehnik na velikost in urejenost por. Sintetizirane materiale smo karakterizirali z uporabo dušikove sorpcije ter s tem pridobili podatke o specifični površini ter poroznosti. Urejenost porozne matrice smo analizirali z rentgensko praškovno difrakcijo pri nizkih kotih. Morfologijo in velikost delcev smo proučili z elektronsko mikroskopijo ter analizo dinamičenga sipanja svetlobe. Rezultati kažejo, da lahko z dodatkom TMB-ja in maščobnih kislin učinkovito uravnavamo velikost por v mezoporoznih SiO$_2$ materialih, kar odpira možnosti za prilagoditev teh materialov specifičnim potrebam različnih aplikacij. Drugi del raziskave se je osredotočal na primer praktične uporabe materialov v namene absorpcije in potencialne uporabe kot dostavne sisteme zdravilnih učinkovin. Kot modelno molekulo sem v porozno matrico adsorbiral ibuprofen. Ugotovil sem, da je hitrost raztapljanja ibuprofena adsorbiranega na SiO2 večja kot hitrost raztapljanja ibuprofena, ki ni bil adsorbiran.

• Language: Slovenian
• Keywords: mezoporozni SiO$_2$, MCM-41, uravnavanje velikosti por, trimetilbenzen, soli maščobnih kislin, ibuprofen
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2024
• PID: 20.500.12556/RUL-162764
• COBISS.SI-ID: 216786179
• Publication date in RUL: 27.09.2024

Secondary language

• Language: English
• Title: Synthesis and characterization of mesoporous SiO$_2$ materials with additives for pore size tuning

Abstract

The thesis focuses on the synthesis and characterization of mesoporous SiO$_2$ materials with additives for pore size tuning. Due to their unique properties, such as large specific surface area and ordered pore structure, mesoporous materials are suitable for various applications, including catalysis, adsorption, drug delivery and application in sensoring. The main objective of the research was to study the impact of different additives, such as 1,3,5-trimethylbenzene (TMB) and fatty acid salts with varying alkyl chain lengths, on the size and order of the pores. The materials were synthesized using the sol-gel method in the presence of a surfactant that acted as a structure-directing agent. We varied synthesis conditions, such as the temperature and pH of the reaction mixture, and the type and concentration of the additives for pore size tuning, such as TMB and fatty acid salts with different alkyl chain lengths. In addition to varying the synthesis conditions, we also examined the effect of post-synthesis hydrothermal treatment on the selected samples and the influence of different techniques for removing the structure-directing agent. We studied the impact of extraction, thermal treatment (calcination), and a combination of both techniques on the pore size and order. The synthesized materials were characterized using nitrogen adsorption, providing data on specific surface area and porosity. The ordering of the porous matrix was analyzed by low-angle X-ray powder diffraction. The morphology and particle size were examined by electron microscopy and dynamic light scattering analysis. The results show that by adding TMB and fatty acids, the pore size in mesoporous SiO$_2$ materials can be effectively controlled, which opens up possibilities for tailoring these materials to meet the specific needs of various applications. The second part of the research focused on a potential application of the materials for use as drug delivery systems. Ibuprofen was adsorbed into the porous matrix as a model molecule. I found that the release rate of adsorbed ibuprofen is faster than the dissolution rate of non-adsorbed ibuprofen.

• Keywords: mesoporous SiO$_2$, MCM-41, pore size tuning, trimethylbenzene, fatty acid salts, ibuprofen