TY - BOOK
T1 - Exploring the Dihydroazulene/Vinylheptafulvene Photoswitch for Solar Thermal Energy Storage
AU - Hansen, Mia Harring
PY - 2018
Y1 - 2018
N2 - Solar energy is a sustainable energy source, which offers an alternative to the climate-damaging fossil fuels, but solar energy fluctuates both daily and annually. Therefore, effective storage solutions need to be provided for a complete transition to renewable energy sources. The objective of this thesis is to use molecular solar thermal (MOST) systems to efficiently store solar thermal energy in chemical bonds. Various approaches to optimize the properties of the dihydroazulene (DHA)/vinylheptafulvene (VHF) photoswitch are examined. A metal nanoparticle (NP) placed in near proximity can alter molecular properties. Retardation effects are implemented into the discrete interaction model (DIM) to be able to correctly describe the interaction of large metal NP and DHA molecules placed in an electromagnetic field. However, the combination of retardation and screening results in an incorrect representation of the interaction tensor. Computational screening studies using density functional theory (DFT) investigate electron donating/withdrawing substituent effects on different positions of DHA/VHF systems, which provides insight into future optimal MOST designs. A quantum mechanics (QM)/molecular mechanics (MM) approach is applied to analyse the influence on the DHA/VHF system of a nearby gold nanoparticle (NP). The effect of molecular conformation, relative orientation, and proximity to the NP on the molecular properties are studied. A simulation framework for a molecular solar thermal (MOST)/solar water heating (SWH) hybrid device is developed. It can predict thermal energy storage rates, conversion percentages, and temperature increases of the MOST fluid throughout the device. The model offers a theoretical assessment before constructing a hybrid device or simply test the potential of a promising MOST system. The simulation framework forms a vital link between fundamental chemistry and engineering. Finally, the potential heat release from the back-conversion is measured in a macroscopic experimental set-up. The results presented in this thesis demonstrate how far we still are from having a commercially available solution, where the DHA/VHF photoswitch works as a solar thermal storage unit. However, multiple solutions to improve the properties of the DHA/VHF system are presented.
AB - Solar energy is a sustainable energy source, which offers an alternative to the climate-damaging fossil fuels, but solar energy fluctuates both daily and annually. Therefore, effective storage solutions need to be provided for a complete transition to renewable energy sources. The objective of this thesis is to use molecular solar thermal (MOST) systems to efficiently store solar thermal energy in chemical bonds. Various approaches to optimize the properties of the dihydroazulene (DHA)/vinylheptafulvene (VHF) photoswitch are examined. A metal nanoparticle (NP) placed in near proximity can alter molecular properties. Retardation effects are implemented into the discrete interaction model (DIM) to be able to correctly describe the interaction of large metal NP and DHA molecules placed in an electromagnetic field. However, the combination of retardation and screening results in an incorrect representation of the interaction tensor. Computational screening studies using density functional theory (DFT) investigate electron donating/withdrawing substituent effects on different positions of DHA/VHF systems, which provides insight into future optimal MOST designs. A quantum mechanics (QM)/molecular mechanics (MM) approach is applied to analyse the influence on the DHA/VHF system of a nearby gold nanoparticle (NP). The effect of molecular conformation, relative orientation, and proximity to the NP on the molecular properties are studied. A simulation framework for a molecular solar thermal (MOST)/solar water heating (SWH) hybrid device is developed. It can predict thermal energy storage rates, conversion percentages, and temperature increases of the MOST fluid throughout the device. The model offers a theoretical assessment before constructing a hybrid device or simply test the potential of a promising MOST system. The simulation framework forms a vital link between fundamental chemistry and engineering. Finally, the potential heat release from the back-conversion is measured in a macroscopic experimental set-up. The results presented in this thesis demonstrate how far we still are from having a commercially available solution, where the DHA/VHF photoswitch works as a solar thermal storage unit. However, multiple solutions to improve the properties of the DHA/VHF system are presented.
UR - https://rex.kb.dk/primo-explore/fulldisplay?docid=KGL01011928888&context=L&vid=NUI&search_scope=KGL&tab=default_tab&lang=da_DK
M3 - Ph.D. thesis
BT - Exploring the Dihydroazulene/Vinylheptafulvene Photoswitch for Solar Thermal Energy Storage
PB - Department of Chemistry, Faculty of Science, University of Copenhagen
ER -
