Controlling the Morphology and Optical Properties of Nanostructured Materials: From Inorganic Nanoparticles to Conjugated Polymers

Soft materials such as nanoparticles and polymers show properties that are highly dependent on the nanoscale morphology as well as compositions. Thus, the ability to control their nanoscale morphology is important for both fundamental understanding and technological applications of nanomaterials. My thesis work concerned two distinct nanomaterials possessing strong structure-dependent optical properties: 1) silica-based multicomponent nanoparticles and 2) amphiphilic conjugated block copolymers. The multicomponent colloidal nanoparticles were composed of a fluorescent core and a metal shell separated by a silica spacer, where the florescence intensity from the core was controlled by adjusting the spacer thickness by layer-by-layer synthesis. The supramolecular assemblies of amphiphilic conjugated block copolymers exhibited highly tunable photoluminescence properties depending on their self-assembly structures. These studies demonstrated that the specific structures can be designed and synthesized to improve the material properties and that the optical properties can be controlled by the self-assembled structures in a predetermined way

Recent insights into the biological functions of apigenin

Apigenin (4′,5,7-trihydroxyflavone) belongs to the group of flavonoids positioned on the backbone of 2-phenylchromen-4-one (2-phenyl-1-benzopyran-4-one) and is most extensively allocated in herbs, vegetables, and fruits. Biosynthetically, apigenin is obtained from the phenylpropanoid pathway and also from the flavone synthesis pathway. The pathway of phenylpropanoid begins from the aromatic amino acids L-phenylalanine or L-tyrosine, both products of the shikimate pathway. In several recent studies, it has been shown that apigenin has a number of valuable bioactive functions, including antibacterial, antiviral, antiproliferative, anti-inflammatory, antioxidant, antiangiogenic, and anticancer activities. From the results of several in vivo and in vitro studies and clinical trials, apigenin has been shown to be an effective curative treatment for rheumatoid arthritis, autoimmune disorders, Parkinson’s disease, Alzheimer’s disease, and several types of cancers. Here, we summarize the key findings of the biological and pharmacological actions of apigenin

Investigation Of Catalytic Sorbents For Capture And Conversion Of CO2 To Methane

The goal of this thesis is to develop dual function materials (DFM), or a catalytic sorbent, that has higher CO2 sorption and CO2 hydrogenation (methanation) capacities than currently existing materials and study fundamentals of CO2 methanation over the synthesized catalytic sorbents. In the first objective, NaNO3 promoted MgO was synthesized and its capability as a sorbent material for integrated capture and conversion application was evaluated. The CO2 sorption mechanism was explored using in-situ XRD and in-situ FTIR measurements, and isothermal regeneration of the sorbent was performed using the new sorbent. In the second objective, integrated capture and conversion was performed using a catalytic sorbent comprised of NaNO3/MgO + Ru/Al2O3. Higher sorption and methane production capacity were obtained, and the CO2 methanation reaction pathway was investigated over the 1% Ru/Al2O3 catalyst and 5% NaNO3/1%Ru/Al2O3 catalyst as well. In the last objective, in depth mechanistic study was performed using operando FTIR and steady state isotopic transient kinetic analysis (SSITKA) to observe the effect of loading of Ru and the presence of NaNO3 on the CO2 methanation reaction mechanism over Ru/Al2O3 catalysts. This research provides more effective catalytic sorbents than previously studied materials in integrated capture and conversion applications, and reveals underlying mechanism(s) of CO2 methanation over the synthesized materials.Ph.D