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Design Of Active Pharmaceutical Ingredients Solid States In Crystallization Processes, Weizhong Gong Jan 2024

Design Of Active Pharmaceutical Ingredients Solid States In Crystallization Processes, Weizhong Gong

Electronic Thesis and Dissertation Repository

Crystallization is an important technique to obtain solid-state drugs from solutions. Physicochemical properties of the active pharmaceutical ingredients (APIs) are determined by crystallization. More than half of the active pharmaceutical ingredients exhibit polymorphism, the phenomenon of chemical species showing more than one unit-cell structure in the solid state. Controlling polymorphism is one of the most important goals during pharmaceutical manufacturing. Nevertheless, the control of polymorphism is sometimes not enough to realize the targeted physicochemical properties. Suitable additives (coformers/salt formers) are explored to generate new multi-component solid phases of poorly soluble/bioavailable active pharmaceutical ingredients (APIs). The design of pharmaceutical cocrystals and …


The Effect Of Steam Explosion On Lipids Extraction From Microalgae And Derivation Of Pectin Films From Waste Culture, Shahil Chhiba Jan 2024

The Effect Of Steam Explosion On Lipids Extraction From Microalgae And Derivation Of Pectin Films From Waste Culture, Shahil Chhiba

Electronic Thesis and Dissertation Repository

The objective of this study was to investigate the properties of sustainable replacements for plastics and diesel fuel, derived from microalgae (Chlorella vulgaris) subjected to steam explosion. During the process, oven temperatures of up to 500 °C were reached, with the experiments left for different times after reaching their maximum internal temperature. Lipids were extracted from algal cultures using a modified Folch method. The waste microalgae were combined with pectin and glycerol to form biodegradable films, and their solubilities and tensile strengths were measured. The highest yield was 124 mg lipids/g microalgae from 400 °C steam explosion for …


Investigation Of Foam Based Photobioreactor For The Cultivation Of Chlorella Vulgaris Cpcc 90, Anuradha Krishnan Nov 2023

Investigation Of Foam Based Photobioreactor For The Cultivation Of Chlorella Vulgaris Cpcc 90, Anuradha Krishnan

Electronic Thesis and Dissertation Repository

Today, microalgae are cultured in large-scale systems such as open ponds and photobioreactors. Open pond systems, while not expensive, have disadvantages, including contamination and high water consumption, resulting in increased cost of harvesting and quick evaporation. Photobioreactors overcome some of the challenges of an open pond system. However, the reactor setup, operation, and microalgae harvesting are relatively more expensive when compared to conventional techniques. In this study, a novel foam-based photobioreactor system was applied to investigate both the cultivation and harvest of microalgae using different surfactant agents, i.e., rhamnolipids, Bovine Serum Albumin (BSA), saponin, and the commercial surfactant Pluronic f127 …


Experimental And Simulation Study Of Reactive Silver Ink Droplet Evaporation, Weipeng Zhang Oct 2023

Experimental And Simulation Study Of Reactive Silver Ink Droplet Evaporation, Weipeng Zhang

Electronic Thesis and Dissertation Repository

The evaporation of particle-free silver ink droplets on heated substrates directly impacts the morphology of the resultant silver particles and films. In this thesis, COMSOL Multiphysics simulations of the solvent (water-ethylene glycol mixture) droplet evaporation process are used to explain the microflows, mass transfers, and heat distribution responsible for the experimental observations. The reactive ink incorporates fluoro-surfactant FS-31 and poly (acrylamide) (PAM) to suppress the coffee-ring effect that negatively impacts the electrical conductivity. Experiments show that the droplet evaporation process results in varied silver particle morphology, depending on the locations within the droplet, leading to uneven surfaces. Large particles (3 …


Conversion Of Biomass Derived Tar In A Catalytic Post-Gasification Process, Floria Rojas Chaves Aug 2023

Conversion Of Biomass Derived Tar In A Catalytic Post-Gasification Process, Floria Rojas Chaves

Electronic Thesis and Dissertation Repository

The present MESc thesis reports the performance of a fluidizable CeO2 promoted Ni/γ-Al2O3 catalyst to be used in a post-gasification process for tar removal. The catalysts developed were prepared using the incipient wetness technique and characterized chemically and physically, using the following techniques: N2 Adsorption-Desorption, XRD, NH3 and CO2 TPD, Pyridine-FTIR, H2-TPR, and H2-Pulse Chemisorption. The catalysts were tested in a fluidized CREC Riser Simulator, in the 500°C-550°C temperature range, within 5 s-10 s reaction times, using both steam and steam-H2/CO2 atmospheres.A 2-methoxy-4-methlyphenol (2M4MP) compound was …


Application Of Crystal Engineering In Multicomponent Pharmaceutical Crystals: A Study Of Theory And Practice, Soroush Ahmadi Nasrabadi Aug 2023

Application Of Crystal Engineering In Multicomponent Pharmaceutical Crystals: A Study Of Theory And Practice, Soroush Ahmadi Nasrabadi

Electronic Thesis and Dissertation Repository

Multicomponent crystallization, a prominent strategy in crystal engineering, offers the ability to modify the physicochemical properties of crystals by introducing a secondary component to their lattice structure. Such multicomponent crystals have found widespread application in the pharmaceutical industry. This thesis explores the experimental screening, characterization, application, and theoretical prediction of multicomponent crystals of Active Pharmaceutical Ingredients (APIs).

The first case study investigates a new solvate of Dasatinib which exhibits high instability at room temperature and transforms into a different polymorph upon desolvation. The crystal structure of this compound is obtained, revealing insights into its transient nature and the potential application …


Hydrothermal Liquefaction (Htl) Of Lignocellulosic Biomass For Biocrude Production: Reaction Kinetics And Corrosion-Resistance Performance Of Candidate Alloys For Reactors, Haoyu Wang May 2023

Hydrothermal Liquefaction (Htl) Of Lignocellulosic Biomass For Biocrude Production: Reaction Kinetics And Corrosion-Resistance Performance Of Candidate Alloys For Reactors, Haoyu Wang

Electronic Thesis and Dissertation Repository

In recent years, the rapid increase in the demand for clean energy and green chemicals as well as concerns over the supply and environmental impacts associated with fossil. resources have stimulated intensive research on conversion of bioresources, such as lignocellulosic biomass and biowaste, into energy, fuels, chemicals, and materials.

Hydrothermal liquefaction (HTL) is a unique thermochemical conversion process, particularly applicable for the conversion of wet biomass and biowaste feedstocks. Most of the biomass HTL studies are conducted in batch reactor and focus on the effects of catalysts, reaction temperature and time on production efficiency and chemical properties of the products. …


Investigation Of Heavy Metal Removal From Synthetic Desalter Effluent Using A Two-Step Approach By Micellar-Enhanced Ultrafiltration And Microbial Fuel Cell, Carlos Munoz-Cupa Apr 2023

Investigation Of Heavy Metal Removal From Synthetic Desalter Effluent Using A Two-Step Approach By Micellar-Enhanced Ultrafiltration And Microbial Fuel Cell, Carlos Munoz-Cupa

Electronic Thesis and Dissertation Repository

Heavy metals in wastewater streams negatively affect the environment due to their high toxicity. Non-conventional heavy metal removal methods show higher efficiencies for the remediation of these pollutants. In this investigation, a two-step approach using micellar-enhanced ultrafiltration (MEUF) and microbial fuel cell (MFC) was investigated to remove copper, manganese, and zinc from a synthetic salt wastewater containing magnesium, sodium, and phenol. This synthetic solution was used to simulate refinery wastewater streams such as desalter effluent. The study was carried out in three phases. In the first phase, a flat plate polyether sulfone membrane was investigated for the MEUF process with …


Value Added Products From Nonconventional Agricultural Biomass Waste Through Thermochemical Transformation, Nicolas A. Sarmiento Feb 2023

Value Added Products From Nonconventional Agricultural Biomass Waste Through Thermochemical Transformation, Nicolas A. Sarmiento

Electronic Thesis and Dissertation Repository

The alteration of temperature patterns around the world has become noticeable in the recent decade. Sea level rise, wildfires, and high temperatures have made people realize that climate change is affecting humans more tangibly than ever. Therefore, the United Nations have pushed to make policies to mitigate this problematic situation. This research investigated the production of biochar from agricultural waste through pyrolysis for fighting climate change and adding value to waste. Experiments in a laboratory scale reactor were conducted to obtain yields of pyrolytic products. Then, analysis of products provided data for characterization and the LCA of the tomato plant …


Effect Of Process Parameters On The Mechanical Properties Of Carbon Fiber Epoxy Composites By Wet Compression Molding, Saboora Ayatollahi Feb 2023

Effect Of Process Parameters On The Mechanical Properties Of Carbon Fiber Epoxy Composites By Wet Compression Molding, Saboora Ayatollahi

Electronic Thesis and Dissertation Repository

In recent years, due to growing environmental concerns, composite materials have emerged as a promising lightweight alternative for metals in structural applications in automobiles. Among composite manufacturing processes, Wet Compression Molding (WCM) is a new method of producing Carbon Fiber Reinforced Polymer (CFRP) components. For similar processes like RTM, operating conditions are always one of the factors that impact the mechanical performance of CFRP parts. Thus, this thesis aimed to investigate the effects of operating conditions, including resin temperature, mold temperature, resin set time, gap closure speed, and mold curing time on the mechanical property of the composite parts. In …


Modeling And Multi-Objective Optimization Of Wastewater Treatment Process, Navneet Kaur Jan 2023

Modeling And Multi-Objective Optimization Of Wastewater Treatment Process, Navneet Kaur

Electronic Thesis and Dissertation Repository

Wastewater is water that has already been used and requires treatment before releasing it into natural water bodies like lakes and rivers. Wastewater treatment is the process of removing impurities from wastewater. In this treatment process, the impurities are removed and converted to effluent. This effluent is returned to the water cycle with minimum impact on the environment. Conventional treatment plants consist of three stages: primary, secondary, and tertiary treatment. Treatment of wastewater is quite complicated because of the number of stages involved in this process. Most wastewater treatment plants are operated manually therefore at times it becomes difficult for …


Quantification Of Flows Emerging From Small Pores In Plane Walls, Matia Peter Edwards Nov 2022

Quantification Of Flows Emerging From Small Pores In Plane Walls, Matia Peter Edwards

Electronic Thesis and Dissertation Repository

Current membrane separation processes are limited in high production and high purity settings due to a trade-off between selectivity and permeance. Methods of creating nanoscale geometries in 2D materials are emerging and present an opportunity for fast, size selective mass transport that can be tailored to a wide array of applications. This thesis develops a method for quantifying flow through small pores in plane walls based on the behaviour of a solute dispersed in a downstream reservoir. This method is validated for a range of micropore diameters, for which flow rates can be calculated with confidence, and is shown to …


Production Of Cellulose-Based Superabsorbent Polymers For Soil Water Retention, Rosa Maria Arredondo Ramirez Nov 2022

Production Of Cellulose-Based Superabsorbent Polymers For Soil Water Retention, Rosa Maria Arredondo Ramirez

Electronic Thesis and Dissertation Repository

Superabsorbent polymers (SAPs) have attracted tremendous attention, with researchers noting that their high water absorption capacity (AC) is valuable for various applications, especially in agricultural contexts. Two types of materials can be used to produce SAPs: fossil-based (which are harmful to the environment) and bio-based (which are significantly more environmentally friendly, given their biodegradability and minimal toxic side effects). Although bio-based SAPs (Bio-SAPs) are preferable due to their environmental merits, their preparation tends to be time consuming and labour intensive, and their AC is still far below expectations. To address these problems, a novel, eco-friendly, cellulose-based superabsorbent polymer (Cellulo-SAP) was …


Identification And Distribution Analysis Of The Mid-Phase In A Low-Velocity Gas-Solid Fluidized Bed, Zhenan Zhang Aug 2022

Identification And Distribution Analysis Of The Mid-Phase In A Low-Velocity Gas-Solid Fluidized Bed, Zhenan Zhang

Electronic Thesis and Dissertation Repository

The intermediate phase in low-velocity gas-solid fluidized beds generally presents excellent gas-solid contact in the systems. However, no comprehensive understanding of this vital phase is available in the literature. Therefore, this study proposed a statistical method to identify this intermediate phase, named ‘mid-phase’ in this thesis, to interpret the system performance based on the analysis of solids holdup in a low-velocity gas-solid fluidized bed.

The distributions of the mid-phase are investigated along both radial and axial directions in consideration of different flow regimes. The result shows that the turbulent regime contains a higher amount of mid-phase and the spatial mid-phase …


Development Of Photocatalytic Reactor System For Dye Degradation From Lab To Pilot Scale, Waleed Jadaa May 2022

Development Of Photocatalytic Reactor System For Dye Degradation From Lab To Pilot Scale, Waleed Jadaa

Electronic Thesis and Dissertation Repository

The overall goal of the research is to develop a novel photocatalytic reactor system, namely, a bubble column photoreactor for the degradation of resistant pollutants, with a particular emphasis on azo dyes. To achieve the objective, different sub-objectives were performed employing lab and pilot-scale reactors with the application of simulated wastewater. Direct Blue (DB15) was used as a model compound for the azo dyes class for this study. Firstly, the influence of various variables such as pH, dye concentration, and catalyst loading to determine optimal combinations of DB15 removal. The experiments were conducted in a swirl flow photoreactor under the …


Novel Fed-Batch Process With In-Situ Product Recovery For Glycerol Fermentation To Butanol Using Clostridium Pasteurianum, Ammi Jani Apr 2022

Novel Fed-Batch Process With In-Situ Product Recovery For Glycerol Fermentation To Butanol Using Clostridium Pasteurianum, Ammi Jani

Electronic Thesis and Dissertation Repository

Butanol, a next-generation biofuel, can be produced by fermenting glycerol using Clostridium pasteurianum. To address product inhibition, an integrated system that combined a fed-batch process with pervaporation was assessed against conventional batch and fed-batch fermentations. This study showed that with the novel process configuration, the productive fermentation time could be extended, translating to a 2.4-fold and 1.9-fold increase in butanol production relative to baseline fed-batch and batch operation, respectively. Further, it was demonstrated that butanol concentrations were able to be maintained below inhibitory levels throughout the fermentation. Despite this outcome, metabolic oscillations were revealed, indicating instability in the process. The …


Co-Gasification Of Biomass And Plastic Waste In A Bubbling Fluidized Bed Reactor, Islam Elghamrawy Apr 2022

Co-Gasification Of Biomass And Plastic Waste In A Bubbling Fluidized Bed Reactor, Islam Elghamrawy

Electronic Thesis and Dissertation Repository

Plastics are versatile, durable, and can be manipulated to match different needs. The COVID-19 pandemic has demonstrated the importance of reducing plastic waste and is believed to be responsible for increasing the generation of plastic waste by 54,000 tons/day which was reported in 2020. Another widely available waste is biomass waste. Agriculture and agroforestry, forest and wood processing, municipal waste, and the food industry are all considered major producers of biowaste. Co-gasification is considered one of the most promising methods of chemical recycling that targets the production of syngas (hydrogen and carbon monoxide) and light hydrocarbon gases. In this study, …


The Electrical, Thermal, And Morphological Properties Of Microinjection-Molded Polypropylene Nanocomposites, Renze Jiang Mar 2022

The Electrical, Thermal, And Morphological Properties Of Microinjection-Molded Polypropylene Nanocomposites, Renze Jiang

Electronic Thesis and Dissertation Repository

Microinjection molding (µIM) exhibits significantly higher shear rates and faster cooling rates, as compared to conventional injection molding, which affect the characteristics of its final products. The effect of carbon black (CB), carbon nanotubes (CNT), and graphene nanoplatelet (GNP) fillers on the electrical conductivity properties of microinjection-molded polypropylene (PP) nanocomposites was systematically studied. Results showed the electrical conductivity properties of PP/CNT and PP/CB microparts were significantly influenced by mold geometry. PP/CNT/CB hybrid filler microparts demonstrated synergistic increases in electrical conductivity and crystallization temperature with higher CNT loading. Morphological observations indicated significant CB and CNT phase separation. Powder-PP/GNP composites exhibited higher …


Sol-Gel Derived Bioceramic Poly(Diethyl Fumarate – Co – Triethoxyvinylsilane) Composite, Aref Sleiman Mar 2022

Sol-Gel Derived Bioceramic Poly(Diethyl Fumarate – Co – Triethoxyvinylsilane) Composite, Aref Sleiman

Electronic Thesis and Dissertation Repository

Synthetic bone graft materials have become an increasingly popular choice for bone augmentation. Ceramic-based and polymer-based bone graft materials constitute the two main classes of synthetic bone graft materials. This study investigated the synthesis of novel bioactive composites for their potential use as bone graft biomaterials. Poly(diethyl fumarate-co-triethoxyvinylsilane)/bioceramic class II organic/inorganic hybrid biomaterials were synthesized via a sol gel process. These biomaterials were then reacted with an ammonium phosphate solution to prepare their respective composites. For the first time, we successfully synthesized sol-gel derived bioceramic poly(diethyl fumarate-co-triethoxyvinylsilane) composites. In vitro bioactivity evaluation of poly(diethyl fumarate-co-triethoxyvinylsilane)/bioceramic composites in simulated body fluid …


Investigation Of Column Packing & Flow Profiles In Packed Chromatographic Columns, Karamjit Singh Dec 2021

Investigation Of Column Packing & Flow Profiles In Packed Chromatographic Columns, Karamjit Singh

Electronic Thesis and Dissertation Repository

Liquid chromatography is an important downstream operation in the health care, biotechnology, biopharmaceutical, and bioprocessing industries. Its high resolving power is utilized to capture valuable materials such as therapeutic proteins, antibodies, peptides, and nucleic acids. Column chromatography relates to a separation and/or purification technique in which a stationary "bed" of a packing medium or resin is contained within a rigid tube. The column efficiency is measured in terms of Number of plates and Asymmetry. Column Efficiency loss can occur during packing, during storage and during transportation. The detailed study has been done for column sizes 2.5 cm and 5 cm …


Thermochemical Conversion Of Plastic To Value Added Products, Anastasia L. Maslak Dec 2021

Thermochemical Conversion Of Plastic To Value Added Products, Anastasia L. Maslak

Electronic Thesis and Dissertation Repository

In this study, the use of pyrolytic cracking for managing non-recyclable plastic waste by conversion into value-added liquid and gaseous products was investigated. A single-stage reactor and a novel, two-stage reactor set-up were used for experiments involving polyethylene and polypropylene. Parameters including feedstock composition, feed rate, temperature and residence time were studied. The two-stage approach was investigated to overcome existing transportation limitations involved in the typical plastic waste lifecycle. Bulky plastic collected in towns and cities must be transported to industrial facilities typically located elsewhere for reprocessing. Both HDPE and LDPE showed promising results for olefin recovery with ethylene gas …


Overcoming Technological Challenges For The Commercialization Of The Circulating Fluidized Bed Bioreactor For Municipal Wastewater Treatment, Michael J. Nelson Dec 2021

Overcoming Technological Challenges For The Commercialization Of The Circulating Fluidized Bed Bioreactor For Municipal Wastewater Treatment, Michael J. Nelson

Electronic Thesis and Dissertation Repository

The fluidized bed bioreactor as an attached growth wastewater treatment process has demonstrated advantages over suspended growth processes for municipal wastewater treatment applications. However, previous studies have also demonstrated potentially serious disadvantages in terms of energy consumption and maximum reactor size of high flow applications.

In this work, a cost analysis using the CapdetWorks, supplemented by calibrated model data taken from GPS-X was performed to determine the cost effectiveness of the circulating fluidized bed bioreactor (CFBBR). This study demonstrated that the CFBBR is most cost competitive at low flow below 5 MGD. A 10%-20% reduction in net present values on …


A Novel Submerged Photocatalytic Oscillatory Membrane Reactor For Effluent Water Polishing, Siddharth Gupta Nov 2021

A Novel Submerged Photocatalytic Oscillatory Membrane Reactor For Effluent Water Polishing, Siddharth Gupta

Electronic Thesis and Dissertation Repository

With water scarcity being identified as a serious challenge around the world, wastewater recycling is paramount for effective water management. To achieve effective water reuse while maintaining low treatment cost, process-intensification (PI) of tertiary treatment technologies is imperative.

In this research, multilayer process-intensification approaches are investigated for effluent water polishing. Initially, the performance of a hybrid submerged photocatalytic membrane reactor (SPMR) was investigated. In a SPMR, both pollutant degradation and catalyst separation (from the permeate) occur in a single modular unit.

The design was enhanced by imparting periodic shear at the membrane surface via membrane oscillation acting as a second …


Non-Circular Hydraulic Jumps Due To Inclined Jets, Ahmed Mohamed Abdelaziz Oct 2021

Non-Circular Hydraulic Jumps Due To Inclined Jets, Ahmed Mohamed Abdelaziz

Electronic Thesis and Dissertation Repository

When a laminar inclined circular jet impinges on a horizontal surface, it forms a non-circular hydraulic jump governed by a non-axisymmetric flow. In this thesis, we use the boundary-layer and thin-film approaches in the three dimensions to theoretically analyse such flow and the hydraulic jumps produced in such cases. We particularly explore the interplay among inertia, gravity, and the effective inclination angle on the non-axisymmetric flow.

The boundary-layer height is found to show an azimuthal dependence at strong gravity level only; however, the thin film thickness as well as the hydraulic jump profile showed a strong non-axisymmetric behaviour at all …


Atomically Thin Nanoporous Graphene Membranes For Fluid Separation, Anika O. K. Wong Aug 2021

Atomically Thin Nanoporous Graphene Membranes For Fluid Separation, Anika O. K. Wong

Electronic Thesis and Dissertation Repository

Membrane separation applications such as water desalination and carbon capture require high permeance and selectivity. For such processes, nanoporous graphene membranes promise 100-fold higher permeance at comparable selectivity to conventional polymer membranes, but remain under development. This thesis reports fluid permeance through both simulated and experimental graphene nanopores. Molecular dynamics simulations were performed to investigate liquid advection-diffusion through graphene nanopores and how the transport rates differ from continuum predictions. Furthermore, a technique for measuring the gas permeance of nanoscopic areas of graphene was developed. Here, a single layer of graphene seals a ~10 nm diameter hole in a multi-layer graphene …


Investigation Of Electrochemical And Hybrid Microbial Desalination Cells For Environmental Applications, Shawn Nicholas Hamilton Aug 2021

Investigation Of Electrochemical And Hybrid Microbial Desalination Cells For Environmental Applications, Shawn Nicholas Hamilton

Electronic Thesis and Dissertation Repository

ABSTRACT

Road salt is a global problem especially in cold countries that are focused on road safety in urbanized and big cities. On an average approximately 5 million tonnes of road salt is applied on Canadian highways annually. Road salt impacts aquatic ecosystems, bridges, buildings and corrodes metal structures. Therefore the treatment of road salt is important and needs to be studied.

In this study, a batch lab-scale 3-compartment electrochemical desalination cell was invented and studied to reduce NaCl(aq) (model of road salt) through the utilization of NaBH4/H2O2 redox reaction. Using of several commercial …


Co2 Derived Carbon Capture Using Microalgae In A Photobiocrec Unit, Maureen D. Cordoba Perez Aug 2021

Co2 Derived Carbon Capture Using Microalgae In A Photobiocrec Unit, Maureen D. Cordoba Perez

Electronic Thesis and Dissertation Repository

Microalgae has the potential to contribute to carbon dioxide capture, resulting in the production of alternative fuels and valuable chemical products. To accomplish this, high-efficiency photobioreactors must be conceptualized, designed, and established, in order to achieve high inorganic carbon conversion, superior light utilization, and unique fluid dynamics.

In this PhD Dissertation, experiments with Chlorella vulgaris were carried out, in a 0.175L especially designed PhotoBioCREC unit, under controlled radiation and high mixing conditions. This unique design involves 1 mm-2 mm alumina particles, which keep photoreactor walls always clean, without compromising photon transmittance. Sodium bicarbonate (NaHCO3) was supplied as the …


Experimental Study And Characterization Of Bubble Behaviors In The Orifice-Induced Hydrodynamic Cavitation, Haoxuan Zheng Aug 2021

Experimental Study And Characterization Of Bubble Behaviors In The Orifice-Induced Hydrodynamic Cavitation, Haoxuan Zheng

Electronic Thesis and Dissertation Repository

Experimental studies were performed to characterize the development process of orifice-induced cavitation and transitional bubble behaviors. The transition from non-cavitation to fully developed cavitation was carefully studied. Cavitation bubble clouds were observed at orifice, indicating the inception of cavitation. The number of bubbles produced were dramatically increased while the averaged sizes of bubble reduced when cavitation was initiated. Both orifice opening ratio and perimeter can affect the cavitation developing process. A long orifice perimeter promotes the production of fine bubbles. The orifice plates with the smallest opening ratio generated a desired gas-liquid interfacial area at the lowest required pressure. An …


Hydrogen Production Via Photocatalytic Water Splitting Under Near-Uv And Visible Light Using Doped Pd Tio2, Bianca Rusinque Aug 2021

Hydrogen Production Via Photocatalytic Water Splitting Under Near-Uv And Visible Light Using Doped Pd Tio2, Bianca Rusinque

Electronic Thesis and Dissertation Repository

The present PhD thesis reports the modification of titanium dioxide (TiO2) with palladium (Pd), to enhance hydrogen production via water splitting, using 2.0v/v% ethanol as a scavenger. Titanium dioxide was used as photocatalyst, given its ability to absorb photons, producing e-/h+ pairs. Mesoporous TiO2 was synthesized using a soft template, following the sol-gel method, to modify its morphological properties. Palladium was used as co-catalyst doping TiO2 agent, narrowing the band gaps down to 2.51 eV, and creating additional active metal sites.

Water splitting experiments under near-UV and visible light irradiation were carried out …


Inherently Porous Atomically Thin Membranes For Gas Separation, Harpreet Atwal Aug 2021

Inherently Porous Atomically Thin Membranes For Gas Separation, Harpreet Atwal

Electronic Thesis and Dissertation Repository

Membranes made from atomically thin materials promise hundreds of times higher production rates than conventional polymer membranes for separation applications. Graphene is impermeable to gases but becomes selectively permeable once pores are introduced into it but creating trillions of nanopores over large areas is difficult. By instead choosing an inherently porous two-dimensional material with naturally identical pores repeated at high density, we may circumvent this challenge. In this work, we explore the potential of two candidate materials, 2D polyphenylene and graphdiyne. We synthesize cyclohexane-m-phenylene, a monomer of 2D polyphenylene. We then develop an atomic force microscopy technique for measuring the …