Chemical Engineering Commons^™

Preparation, Cure, And Characterization Of Cyanate Ester-Epoxy Blends Containing Reactive Flame Retardants, Mustafa Mukhtar, Donald A. Klosterman

Chemical and Materials Engineering Faculty Publications

Cyanate ester resins are sometimes mixed with lower cost epoxy monomers to modify cost, toughness, and processing capabilities. Despite the high performance of these thermosetting polymers, flame retardancy remains an issue. This study examined blends of three different commercial cyanate ester monomers (LVT-100, LECy, and XU-71787.02) and diglycidyl ether of bisphenol A (DGEBA) at 50/50 wt% of each type. The blends were successfully reacted with two reactive flame retardants (FR): 9,10-dihydro-9-ox-9-phosphaphenanthrene-10-oxide (DOPO) and poly(m-phenylene methylphosphonate) (PMP) at phosphorus contents ranging from 0 to 3 wt%. The curing behavior of EP/CE blends was investigated using differential scanning calorimetry (DSC). It was …

Techno-Economic Analysis And Intensification Of Biosurfactant Production From Palm Fatty Acid For Oil Recovery Enhancement, Chanapol Charoentanaworakun

Chulalongkorn University Theses and Dissertations (Chula ETD)

Currently, Biosurfactants are receiving the interest as a substitute for surfactants synthesized from petroleum products due to their biodegradability. Palm oil derivatives are one of the interesting candidates of biosurfactant production because of the superior properties of hydrocarbon structure in the range of C16-C18. Thus, this research studied the economic and environmental impact analysis of production processes, and adsorption and oil recovery performance for different anionic biosurfactants synthesized from palm oil derivatives, i.e. palm fatty acid distillate (PFAD). Moreover, the optimal design and essential operating condition of batch reactive distillation column were also studied to intensify the equilibrium limitation of …

Shape Memory Polymer Based On Copolybenzoxazines: Effects Of Chain Length Of Aliphatic Monoamines On Shape Memory Performance, Attachai Sriwattana

Chulalongkorn University Theses and Dissertations (Chula ETD)

This research was successful in completely synthesizing benzoxazine copolymers for shape memory polymers (SMPs) by mixing bisphenol A-aniline (BA-a) and bisphenol A-aliphatic monoamines of various chain lengths (BA-aMAs). Our studies have shown that shorter chain lengths will provide higher crosslinking densities, which play an important role in promoting the stiffness of the polymer, resulting in a higher shape-fixity ratio (Rf). While longer chains result in a lower crosslinking density and a larger free volume, thus promoting a higher shape-recovery ratio (Rr), Therefore, selecting the appropriate aliphatic monoamine chain length is crucial. From the study of this work, it was found …

Sustainable Toughening Of Polylactic Acid With Ultra-Fine Fully Vulcanized Powdered Natural Rubber, Reza Gholami

Chulalongkorn University Theses and Dissertations (Chula ETD)

This study investigated the sustainable toughening of polylactic acid (PLA) by incorporating ultra-fine fully vulcanized powdered natural rubber graft-copolymerized with poly-styrene-co-acrylonitrile (UFPNR-SAN). We investigated the effect of the styrene-to-acrylonitrile ratio (ST:AN) used during the grafting process on the final UFPNR-SAN compatibility with PLA. The ST:AN ratio was systematically varied during the grafting reaction to prepare UFPNR-SAN with a range of different surface energies. The ST:AN ratio of 4:1 resulted in higher compatibility of UFPNR-SAN with the PLA matrix among other ratios. This could be explained by the desirable interfacial interactions and better dispersion shown by the contact angle measurements and …

Green Synthesis For Silver Nanoparticle /Natural Rubber/ Nanocellulose Bio-Polymeric Composites, Puttakhun Meemai

Chulalongkorn University Theses and Dissertations (Chula ETD)

A green synthesis method was developed to produce biobased semiconducting composites of silver nanoparticles (AgNPs), skim natural rubber (SNR), and bacteria cellulose. A solution of silver nitrate (AgNO3) ranging from 40 to 160 mM was added to skim natural rubber latex (SNRL) to facilitate the reduction of silver ions to AgNPs at temperatures between 50 and 80 °C. Subsequently, BC pellicle was immersed in the prepared AgNPs-SNRL suspension for 48 hours, followed by washing and drying. The resulting AgNPs/SNR/BC films were then analyzed for their chemical, mechanical, antibacterial, and electrical properties. The strain at break of the films was significantly …

Methyl Isobutyrate Production Via Hydrogenation Of Methyl Methacrylate Derived From Pyrolysis Of Acrylic Plastic Waste, Ramzi Nasser Ahmed Saif

Chulalongkorn University Theses and Dissertations (Chula ETD)

According to zero waste and upcycling policy, this work aims to utilize waste polymethyl methacrylate (PMMA) to methyl isobutyrate (MIB) via hydrogenation over nickel (Ni) based catalysts supported on commercial zeolites: HY, H-Beta-27 (SiO2/Al2O3 = 27 by mole), H-Beta-40 (SiO2/Al2O3 = 40 by mole) and H-ZSM-5. The appropriate catalyst support was first screen by using MMA monomer as the substrate for hydrogenation. Under 30 bar initial H2 pressure (PH2) at 250 °C for 3 h, Ni/H-Beta-27 catalyst effectively promoted hydrogenation to achieve 85% MMA conversion with 56.2 wt% MIB yield because of its larger external surface area and pore size. …

A Comprehensive Review Of The Influence Of Heat Exchange Tubes On Hydrodynamic, Heat, And Mass Transfer In Bubble And Slurry Bubble Columns, Dalia S. Makki, Hasan Sh Majdi, Amer A. Abdulrahman, Abbas J. Sultan, Zahraa W. Hasan, Laith S. Sabri, Bashar J. Kadhim, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bubble and slurry bubble column reactors (BCRs/SBCRs) are used for various chemical, biochemical, and petrochemical applications. They have several operational and maintenance advantages, including excellent heat and mass transfer rates, simplicity, and low operating and maintenance cost. Typically, a catalyst is present in addition to biochemical processes where microorganisms are used to produce industrially valuable bio-products. Since most applications involve complicated gas-liquid, gas-liquid-solid, and exothermic processes, the BCR/SBCR must be equipped with heat-exchanging tubes to dissipate heat and control the reactor's overall performance. In this review, past and very recent experimental and numerical investigations on such systems are critically discussed. …

Effect Of Alkali Metal Functionalization On Hydrogen Storage Performance Of Highly Porous Activated Carbons, Ruthradharshini Murugavel, Ali A. Rownaghi, Fateme Rezaei

Chemical and Biochemical Engineering Faculty Research & Creative Works

With increasing energy demand and fast-paced decarbonization methods adopted to curb the adverse effects of greenhouse gas emissions, hydrogen (H2) is considered a sustainable, clean, and potential renewable energy carrier for the future. To substitute the energy needs required for the physical methods of H2 storage, adsorbed gas storage (AGS) is the next viable option that provides the opportunity to adsorb and desorb gases under mild conditions. In this work, we studied the effect of light alkali metal functionalization comprising Li and K on the H2 storage performance of porous graphitic carbon adsorbents. The effect of metal doping on the …

Comprehensive Evaluation Of A Novel Re-Crosslinkable Preformed Particle Gel For The Water Management Of Reservoir With Concentrated Divalent Ions, Tao Song, Mohamed Ahdaya, Zhanmiao Zhai, Thomas P. Schuman, Baojun Bai

Chemistry Faculty Research & Creative Works

As one of the most widely used technology to ameliorate the reservoir's heterogeneity, polymer gels have been applied for more than 60 years. However, how to plug fractured reservoirs with significant abnormal features, high temperature and high salinity, especially the divalent cations, is still a challenging target. This work systematically evaluated a novel salt-resistant re-crosslinkable preformed particle gel (SR-RPPG) designed for fractured reservoirs with excellent salt resistance (up to 5 % CaCl₂). We evaluated the swelling kinetics, thermal stability and plugging efficiency of this SR-RPPG. We assessed the swelling kinetic and re-crosslinking behavior of the SR-RPPG through the …

Effects Of Confinement On Ionic Liquids And Deep Eutectic Solvents For The Design Of Catalytic Systems, Electrochemical Devices, And Separations, Andrew Drake

Theses and Dissertations--Chemical and Materials Engineering

Confinement of ionic liquids (ILs) and deep eutectic solvents (DESs) within mesoporous materials such as silica helps to control the local environment within the pores for applications such as catalysis, electrochemistry, and absorption. Silica thin films with 2.5 and 8 nm pores and micron-sized silica particles with pore diameters of 5.4 and 9 nm were synthesized to study the effect of nanoconfinement on ILs 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF₆]), 1-butyl-3-methylimidazolium chloride ([BMIM][Cl]), and DESs reline and ethaline (choline chloride and urea or ethylene glycol). Silica thin films with vertically aligned, well ordered, and accessible pores were synthesized via the evaporation-induced …

Attrition Study Of Copper-Supplemented Iron-Based Oxygen Carrier For Chemical Looping Combustion, Neng Huang

Theses and Dissertations--Mechanical and Aerospace Engineering

Chemical looping combustion (CLC) is a promising technology that can mitigate the carbon emissions for power generation. The cost of oxygen carriers (OCs) impedes the scale up of CLC. Compared to synthetic iron-based OCs, red mud (RM), an abundant iron-based solid waste from industry, is a cost-effective choice due to its intrinsic inclusion of both inert and catalytic phases that are crucial for CLC. It was anticipated that the addition of copper oxide to RM using a mechanical mixing method that can be easily scaled up would enhance both reactivity and oxygen transport capacity (OTC), and the heat of reaction …

Impact Of Spallation And Internal Radiation On Fibrous Ablative Materials, Raghava Sai Chaitanya Davuluri

Theses and Dissertations--Mechanical and Aerospace Engineering

Space vehicles are equipped with Thermal Protection Systems (TPS) that encounter high heat rates and protect the payload while entering a planetary atmosphere. For most missions that interest NASA, ablative materials are used as TPS. These materials undergo several mass and energy transfer mechanisms to absorb intense heat. The size and construction of the TPS are based on the composition of the planetary atmosphere and the impact of various ablative mechanisms on the flow field and the material. Therefore, it is essential to quantify the rates of different ablative phenomena to model TPS accurately. In this work, the impact of …

Microalgae Immobilization With Filamentous Fungi: Process Development For Sustainable Food Systems, Suvro Talukdar

Theses and Dissertations--Biosystems and Agricultural Engineering

Demand for sustainable food sources has increased because of the rapid growth of the world's population.  In this study, microalgae cells of Haematococcus pluvialis were immobilized using the edible fungal strain Aspergillus awamori for potential food applications. The study investigated the impact of fungal loading, pellet geometry, and initial microalgae cell concentration on the immobilization performance and product characteristics. It was found that higher fungal loading and larger fungal pellets contributed to increased immobilization performance while increased initial microalgae concentration inhibited the process. Larger fungal pellets had decreased biomass density, which led to decreased surface concentration of immobilized microalgae but …

Investigation Of Mechanical Regulation On Stat3 Activity And Mmp Production, Jaxson R. Libby

Honors Theses and Capstones

Transcription factor, STAT3, is inappropriately expressed in cancer cells, and has contrasting activation in 2D versus 3D microenvironments. 2D plates are often used for drug screening and do not always recapitulate in vivo responses. To combat inaccurate 2D drug studies, a 3D hydrogel was created to support the growth of cancer cells into a tumor-like environment. The hydrogel consists of a biocompatible dextran homopolysaccharide, cell adhesion RGD sequences, and crosslinker MMP labile peptides. A pH dependent reaction couples the RGD sequences to dextran then the polymers are crosslinked into a gel. Crosslinking is accomplished using terminal cysteine peptide sequences, allowing …

Treating Contaminated Water: Predicting Reactivities Of Aqueous Organic Contaminants With Hydrated Electrons, And Development Of A Biogarden To Manage Greywater Discharge In Monteverde, Costa Rica, Rose C. Daily

Dissertations, Master's Theses and Master's Reports

Advanced reduction processes (ARPs) that generate highly reactive solvated electrons (e^-_aq) are a promising method for the destruction of conventional and emerging aqueous organic contaminants. While there is a large database of contaminant reactivity with e^-_aq in the literature, there is little information on the detailed elementary mechanisms for reduction of multifunctional group compounds and the impact of those functional groups on reactivity. As it is difficult to determine specific mechanisms through experiments and time consuming to measure reactivity, the development of computational approaches to elucidate mechanisms and predict reactivity is becoming increasingly important. In …

Hydro Cyclonic Separation Of Polyester Microfibers From Washing Machine Wastewater, Joe Kulkarni

Dissertations, Master's Theses and Master's Reports

Clothing made from synthetic materials shed fibers in washing machines, and these fibers find their way into the effluent water. These fibers can absorb toxic materials in wastewater treatment plants and can then carry these toxins into other aquatic environments.

It’s believed that a hydro cyclone could be scaled down enough to fit into a washing machine and could be used to filter out up to 80% of the microparticles from the effluent water. It’s proposed to investigate if a hydro cyclone can be used for this application. The overall goal was for the hydro cyclone to concentrate the micro …

Microscopic And Laboratory Scale Characterization Methods To Evaluate Biomass Deconstruction, Meenaa Chandrasekar

Dissertations, Master's Theses and Master's Reports

Renewable fuels from lignocellulosic biomass are an appealing option because they can seamlessly integrate into the existing fuel distribution infrastructure. Lignocellulosic biomass constitutes nonedible plant material obtained from plant cell walls. The natural recalcitrance of lignocellulosic biomass poses a challenge in accessing the cell wall carbohydrates during biochemical conversion. Despite various approaches, enzymatic hydrolysis of lignocellulosic biomass remains economically impractical due to incomplete knowledge about biomass recalcitrance and the influence of environmental factors on biomass quality.

The first goal of this dissertation was to construct a microfluidic imaging reactor to better understand the tissue-specific deconstruction of plant materials. Confocal laser …

Enhancing Control Room Operator Decision Making: An Application Of Dynamic Influence Diagrams In Formaldehyde Manufacturing, Joseph Mietkiewicz, Anders L. Madsen

Articles

Intoday’s rapidly evolving industrial landscape, control room operators must grapple with an ever-growing array of tasks and respon sibilities. One major challenge facing these operators is the potential for task overload, which can lead to decision fatigue and increased reliance on cognitive biases. To address this issue, we propose the use of dynamic influence diagrams (DID) as the core of our decision support system. By monitoring the process over time and identifying anomalies, DIDs can recommend the most effective course of action based on a probabilistic assessment of future outcomes. Instead of letting the operator choose or search for the …

Direct Recycling Of Lithium-Ion Battery Materials Using Physical Separation Methods., Tinuade Ololade Folayan

Dissertations, Master's Theses and Master's Reports

The increased demand for Lithium-ion batteries for Electric vehicles has influenced worldwide interest in the research and development of methods for recycling end-of-life Lithium-ion batteries. Direct recycling method has gained more attention in recent times as a method that is low-cost with the ability to recover all Lithium-ion battery materials without changing the chemical and structural properties of the recycled materials.

A lithium-ion battery contains a complex mixture of materials with significantly different physical properties. This work develops physical separation techniques as Direct recycling methods to recycle individual battery components without damaging the functional integrity of the recycled materials. In …

Chemical Decomposition Of Flexible Polyurethane Foam To Generate A Media For Microbial Upcycling, Kaushik Baruah

Dissertations, Master's Theses and Master's Reports

Polyurethane waste is becoming a global concern as a large amount is being disposed of in landfills every year, and only a fraction is being recycled. Several polyurethane recycling techniques exist, of which ammonolysis and base-catalyzed hydrolysis is the least explored. Flexible polyurethane foam (FPUF) decomposition can generate amines that can act as a carbon source for the growth of microbial consortia. This study aims to generate a novel media capable of microbial upcycling via ammonolysis and base-catalyzed hydrolysis of flexible polyurethane foams (FPUFs) using ammonium hydroxide and subsequently determine the reaction conditions for maximum solubilization of polyurethane foam in …