Terahertz Spectroscopy as a Tool to Investigate Guest-Host Interactions in Porous Materials
Conference Year
January 2020
Abstract
Porous materials are becoming increasingly popular because they are highly functional, readily produced, economically efficient. There are numerous applications involving porous materials, such as catalysis, gas separation and water purification. However, in order to more effectively use porous materials in advanced applications, it is critical that accurate information related to host-guest interactions be well-understood with atomic-level precision. In this work, two applications of porous materials are investigated, focusing on the nature and dynamics of guest molecules within the porous solid. In the first case, the stabilization of active pharmaceutical ingredients through interactions with mesoporous silica was explored. In the study, the guest-host interaction is characterized experimentally through analysis of the thermodynamics associated with monolayer formation on the porous silica. Using solid-state density functional theory (DFT). The binding energy, molecular conformations, and atomic dynamics were all obtained. The results show that loading the drug molecules into porous silica did increase the stability of the amorphous state by allowing the drug molecules to maximize favorable intermolecular interactions, while simultaneously resulting in a more highly strand intramolecular conformation, revealing the complex energetic interplay between conformational strain and stabilization from external sources. In a second application, the gas-capture and sequestration phenomena in porous materials was studied in hydroquinone (HQ) clathrate materials. A series of gases were studied, including to Noble gases (He, Ne, Ar, Kr, Xe, Rn) as well as carbon dioxide (CO2). By using the terahertz spectroscopy, the dynamics of the gas molecule – porous HQ interaction were uncovered as a function of temperature and pressure. Solid-state DFT simulations help to determine and assign the terahertz spectra of the interaction mechanism. The results also indicate that porous HQ adsorbs the guest gas molecules selectively based on the various energetic forces present within the pores.
Primary Faculty Mentor Name
Michael T. Ruggiero
Status
Graduate
Student College
College of Arts and Sciences
Program/Major
Materials Science
Primary Research Category
Engineering & Physical Sciences
Terahertz Spectroscopy as a Tool to Investigate Guest-Host Interactions in Porous Materials
Porous materials are becoming increasingly popular because they are highly functional, readily produced, economically efficient. There are numerous applications involving porous materials, such as catalysis, gas separation and water purification. However, in order to more effectively use porous materials in advanced applications, it is critical that accurate information related to host-guest interactions be well-understood with atomic-level precision. In this work, two applications of porous materials are investigated, focusing on the nature and dynamics of guest molecules within the porous solid. In the first case, the stabilization of active pharmaceutical ingredients through interactions with mesoporous silica was explored. In the study, the guest-host interaction is characterized experimentally through analysis of the thermodynamics associated with monolayer formation on the porous silica. Using solid-state density functional theory (DFT). The binding energy, molecular conformations, and atomic dynamics were all obtained. The results show that loading the drug molecules into porous silica did increase the stability of the amorphous state by allowing the drug molecules to maximize favorable intermolecular interactions, while simultaneously resulting in a more highly strand intramolecular conformation, revealing the complex energetic interplay between conformational strain and stabilization from external sources. In a second application, the gas-capture and sequestration phenomena in porous materials was studied in hydroquinone (HQ) clathrate materials. A series of gases were studied, including to Noble gases (He, Ne, Ar, Kr, Xe, Rn) as well as carbon dioxide (CO2). By using the terahertz spectroscopy, the dynamics of the gas molecule – porous HQ interaction were uncovered as a function of temperature and pressure. Solid-state DFT simulations help to determine and assign the terahertz spectra of the interaction mechanism. The results also indicate that porous HQ adsorbs the guest gas molecules selectively based on the various energetic forces present within the pores.