Engineering Commons^™

Synthesis And Energy Applications Of Mesoporous Titania Thin Films, Syed Z. Islam

Theses and Dissertations--Chemical and Materials Engineering

The optical and electronic properties of TiO₂ thin films provide tremendous opportunities in several applications including photocatalysis, photovoltaics and photoconductors for energy production. Despite many attractive features of TiO₂, critical challenges include the innate inability of TiO₂ to absorb visible light and the fast recombination of photoexcited charge carriers. In this study, mesoporous TiO₂ thin films are modified by doping using hydrogen and nitrogen, and sensitization using graphene quantum dot sensitization.

For all of these modifiers, well-ordered mesoporous titania films were synthesized by surfactant templated sol-gel process. Two methods: hydrazine and plasma treatments have been …

Tunable Nanocomposite Membranes For Water Remediation And Separations, Sebastián Hernández Sierra

Theses and Dissertations--Chemical and Materials Engineering

Nano-structured material fabrication using functionalized membranes with polyelectrolytes is a promising research field for water pollution, catalytic and mining applications. These responsive polymers react to external stimuli like temperature, pH, radiation, ionic strength or chemical composition. Such nanomaterials provide novel hybrid properties and can also be self-supported in addition to the membranes.

Polyelectrolytes (as hydrogels) have pH responsiveness. The hydrogel moieties gain or lose protons based on the pH, displaying swelling properties. These responsive materials can be exploited to synthesize metal nanoparticles in situ using their functional groups, or to immobilize other polyelectrolytes and biomolecules. Due to their properties, these …

Pore-Confined Carriers And Biomolecules In Mesoporous Silica For Biomimetic Separation And Targeting, Shanshan Zhou

Theses and Dissertations--Chemical and Materials Engineering

Selectively permeable biological membranes composed of lipophilic barriers inspire the design of biomimetic carrier-mediated membranes for aqueous solute separation. This work imparts selective permeability to lipid-filled pores of silica thin film composite membranes using carrier molecules that reside in the lipophilic self-assemblies. The lipids confined inside the pores of silica are proven to be a more effective barrier than bilayers formed on the porous surface through vesicle fusion, which is critical for quantifying the function of an immobilized carrier. The ability of a lipophilic carrier embedded in the lipid bilayer to reversibly bind the target solute and transport it through …