Chemical Engineering Commons^™

The Effect Of Curing And Zirconium Content On The Wettability And Structure Of A Silicate Hybrid Sol-Gel Material, Emma Machugh, Maikki Cullen, Alicja Kaworek, Brendan Duffy, Mohamed Oubaha

Articles

Functional hybrid sol-gel coatings have been developed for numerous applications with a wide range of wettabilities. This study proposes to investigate the relationship between the structure and the wetting properties of a zirconium modified silicate hybrid sol-gel coating. The structures of the coatings were altered by varying the content of zirconium, and the curing process, while keeping the sol-gel preparation conditions identical. The structure of the materials was characterized by FTIR, 29Si NMR and SEM. The thermal properties and the wettability are identified by DSC and contact angle measurements, respectively. By corroborating the structural and wettability analyses, it is shown …

Enhancing The Thermal Stability Of Carbon Nanomaterials With Dna, Mohammad Moein Safee, Mitchell Gravely, Adeline Lamothe, Megan Mcsweeney, Daniel E. Roxbury

Chemical, Biomolecular, and Materials Engineering Faculty Publications

Single-walled carbon nanotubes (SWCNTs) have recently been utilized as fillers that reduce the flammability and enhance the strength and thermal conductivity of material composites. Enhancing the thermal stability of SWCNTs is crucial when these materials are applied to high temperature applications. In many instances, SWCNTs are applied to composites with surface coatings that are toxic to living organisms. Alternatively, single-stranded DNA, a naturally occurring biological polymer, has recently been utilized to form singly-dispersed hybrids with SWCNTs as well as suppress their known toxicological effects. These hybrids have shown unrivaled stabilities in both aqueous suspension or as a dried material. Furthermore, …

Biomolecular Functionalization Of A Nanomaterial To Control Stability And Retention Within Live Cells, Mitchell Gravely, Mohammad Moein Safaee, Daniel E. Roxbury

Chemical, Biomolecular, and Materials Engineering Faculty Publications

Noncovalent hybrids of single-stranded DNA and single-walled carbon nanotubes (SWCNTs) have demonstrated applications in biomedical imaging and sensing due to their enhanced biocompatibility and photostable, environmentally responsive near-infrared (NIR) fluorescence. The fundamental properties of such DNA-SWCNTs have been studied to determine the correlative relationships between oligonucleotide sequence and length, SWCNT species, and the physical attributes of the resultant hybrids. However, intracellular environments introduce harsh conditions that can change the physical identities of the hybrid nanomaterials, thus altering their intrinsic optical properties. Here, through visible and NIR fluorescence imaging in addition to confocal Raman microscopy, we show that the oligonucleotide length …

Ultrasonic Generation Of Pulsatile And Sequential Therapeutic Delivery Profiles From Calcium-Crosslinked Alginate Hydrogels, Tania Emi, Kendra Michaud, Emma Orton, Grace Santilli, Catherine Linh, Meaghan O'Connell, Fatima Issa, Stephen Kennedy

Chemical, Biomolecular, and Materials Engineering Faculty Publications

Control over of biological processes can potentially be therapeutically regulated through localized biomolecular deliveries. While implantable hydrogels can provide localized therapeutic deliveries, they do not traditionally provide the temporally complex therapeutic delivery profiles required to regulate complex biological processes. Ionically crosslinked alginate hydrogels have been shown to release encapsulated payloads in response to a remotely applied ultrasonic stimulus, thus potentially enabling more temporally complex therapeutic delivery profiles. However, thorough characterizations of how different types of therapeutic payloads are retained and ultrasonically released need to be performed. Additionally, the impact of potentially disruptive ultrasonic stimulations on hydrogel structure and temperature need …

Primary Dendrite Trunk Diameter In Al-7wt% Si Alloy Directionally Solidified Aboard The International Space Station, S. R. Upadhyay, Surendra N. Tewari, M. Ghodes, R. N. Grugel, D. R. Poirier, M. Lauer

Chemical & Biomedical Engineering Faculty Publications

Under a NASA (National Aeronautics and Space Agency)-ESA (European Space Agency) collaborative research project, MICAST (Microstructure formation in casting of technical alloys under a diffusive and magnetically controlled convection conditions), three Al-7wt% Si samples (MICAST-6, MICAST-7 and MICAST2-12) were directionally solidified at growth speeds varying from 10 to 50 µm s^-1 aboard the International Space Station to determine the effect of mitigating convection on the primary dendrite array. The observed primary dendrite trunk diameters during steady-state growth of MICAST samples show a good agreement with predictions from a coarsening based model developed by the authors. The trunk diameters in …

Synthesis Of Zif-8 For The Oxidative Dehydrogenation Of Ethane To Produce Ethylene, Fausat Isu

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Degradation And Hydrate Phase Equilibria Measurement Methods Of Monoethylene Glycol, Khalid Alef, Stefan Iglauer, Ahmed Barifcani

Research outputs 2014 to 2021

Monoethylene glycol (MEG), a common chemical used for the inhibition of gas hydrate formation may undergo degradation in the regeneration/reclamation process. Limited research exists on the effect of degradation of MEG on hydrate formation, production facilities and equipment especially in the presence of other chemical additives. The proposed method allows for streamlining the process of preparing, degrading and analysis of MEG solutions for hydrate testing and degradation products.

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Procedure to prepare accurate MEG solutions avoiding oxidative degradation of MEG (i.e., controlling oxygen ingress).

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Two methods are suggested to mimic field-like degradation of MEG solutions (i.e., degradation by reclamation …

Heating Rate And Temperature Effects On Pyrolysis Products From Live Wildland Fuels, Mohammad-Saeed Safdari, Elham Amini, David R. Weise, Thomas H. Fletcher

Faculty Publications

Wildland fire, which includes both planned (prescribed fire) and unplanned (wildfire) fires, is an important component of many ecosystems. During wildland fires, low heating rate pyrolysis (slow pyrolysis) occurs during preheating and/or smoldering of plant material. High heating rate pyrolysis (fast pyrolysis) exists in the flame region. Pyrolysis temperature and heating rate play important roles on the yields and the compositions of pyrolysis products. In this work, the effects of pyrolysis temperature and heating rate on the yields and the compositions of pyrolysis products from 14 plant species native to the forests of the southern United States are shown. The …

Correlations Of The Elemental Compositions Of Primary Coal Tar And Char, Andrew P. Richards, Colson Johnson, Thomas H. Fletcher

Faculty Publications

Simulations of large-scale coal combustors rely on accurate submodels to describe the chemical and physical changes in coal during reaction. Typically, simplified empirical submodels are tuned to experimental data to reduce the computational complexity. When data are not readily available, simplifying assumptions are used, which can create inaccuracies and biases in a large simulation. One such simplifying assumption in coal research is how to describe the elemental composition of primary pyrolysis products. This paper explores several different empirical model forms to predict the dry, ash-free fractions of C, H, O, N, and S in both the char and tar, using …

Modified Cpd Model For Coal Devolatilization At Underground Coal Thermal Treatment Conditions, Ding Wang, Thomas H. Fletcher, Swomitra Mohanty, Hoaquan Hu, Eric G. Eddings

Faculty Publications

To study coal pyrolysis behavior at underground coal thermal treatment (UCTT) conditions, a modified CPD (M-CPD) model was developed and evaluated using two scales of experiments as well as two different coals, Utah Sufco and Illinois #6. Compared with the original CPD model, three major aspects were changed, including (1) rewriting the algorithm using MATLAB built-in functions; (2) developing a correlation method between coal elemental composition and the initial functional group population to calculate the effect of cross-linking on the lattice structure; and (3) using a two-activation energy approach for gas generation kinetics modeling. Results predicted by the M-CPD model …

Characterization Of Pyrolysis Products From Slow Pyrolysis Of Live And Dead Vegetation Native To The Southern United States, Elham Amini, Mohammad-Saeed Safdari, Jonathan Deyoung, David R. Weise, Thomas H. Fletcher

Faculty Publications

Prescribed (i.e., controlled) burning is a common practice used in many vegetation types in the world to accomplish a wide range of land management objectives including wildfire risk reduction, wildlife habitat improvement, forest regeneration, and land clearing. To properly apply controlled fire and reduce unwanted fire behavior, an improved understanding of fundamental processes related to combustion of live and dead vegetation is needed. Since the combustion process starts with pyrolysis, there is a need for more data and better models of pyrolysis of live and dead fuels. In this study, slow pyrolysis experiments were carried out in a pyrolyzer apparatus …

การประเมินค่าพารามิเตอร์ทางจลนศาสตร์สำหรับการออกซิไดซ์โทลูอีนบนตัวเร่งปฏิกิริยา Moo3/Tio2 ที่ได้รับการปรับสภาพด้วยกรดซัลฟิวริกและออกแบบมาเพื่อใช้ในปฏิกิริยา Scr ในการรีดิวซ์ Nox ด้วย Nh3, นภสร นารอด

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้ทำการศึกษาตัวเร่งปฏิกิริยา MoO3/TiO2 บนตัวรองรับ TiO2 ที่ได้รับการปรับสภาพด้วยสารละลาย H2SO4 เข้มข้น 0, 0.2 และ 0.5 M ในการทำปฏิกิริยาโทลูอีนออกซิเดชัน เตรียมตัวเร่งปฏิกิริยาด้วยวิธีการเคลือบฝังแบบเปียก ทำการการวิเคราะห์คุณลักษณะของตัวเร่งปฏิกิริยาด้วยเทคนิค Nitrogen Physisorption, XRD, NH3-TPD และ SEM-EDX การทดสอบความสามารถของตัวเร่งปฏิกิริยาทำในช่วงอุณหภูมิ 120 ถึง 400oC โดยใช้แก๊สผสมที่ประกอบด้วยโทลูอีนเข้มข้น 300 ถึง 400 ppm, O2 เข้มข้น 3, 12 และ 21 %vol ในเครื่องปฏิกรณ์แบบเบดนิ่งอุณหภูมิคงที่ จากการศึกษาพบว่าเมื่อพิจารณาผลของ O2 พบว่าเมื่อเพิ่มความเข้มข้นจาก 3 ถึง 12 % ค่า %Toluene conversion เพิ่มขึ้นอย่างเห็นได้ชัด แต่เมื่อเพิ่ม O2 ความเข้มข้น 12 ถึง 21 % กลับไม่ได้เพิ่มขึ้นมากเมื่อเทียบกับช่วงแรกที่ความเข้มข้นของ O2 ต่ำ พฤติกรรมนี้อาจบ่งชี้ได้ว่า เกิดปฏิกิริยาผ่านกลไกของแบบจำลอง REDOX และแม้ว่า %Toluene conversion จะสูง แต่กลับพบ CO2 ในปริมาณที่ต่ำจนไม่สามารถคำนวณหาปริมาณพื้นที่ที่แน่นอนได้ แสดงว่าผลิตภัณฑ์ที่ได้จากการออกซิไดซ์โทลูอีนนั้น อาจกลายเป็นสารประกอบอินทรีย์ที่มีจุดเดือดสูง เมื่อพิจารณาผลของค่าทางจลศาสตร์ ในกรณีของตัวเร่งปฏิกิริยาที่ไม่ได้รับการปรับสภาพด้วยกรด H2SO4 ในทุกความเข้มข้นของ O2 ปฏิกิริยาเกิดขึ้นด้วยกัน 2 ปฏิกิริยา คือปฏิกิริยาแรกมีค่า Ea ต่ำที่อยู่ในช่วง 21 ถึง 27 kJ/mol ซึ่งตรวจพบได้ในช่วงอุณหภูมิ 150 ถึง 275oC และปฏิกิริยาที่ 2 มีค่า Ea ที่สูงที่อยู่ในช่วง 56 ถึง 68 kJ/mol ซึ่งเห็นได้ในช่วงอุณหภูมิ …

Multi-Responsive Macromolecular Coacervate Complexes For Efficient Biomolecular Encapsulation And Controlled Release, Adrian Lorenzana

Research Opportunities for Engineering Undergraduates (ROEU) Program 2018-19

The project investigates the mechanistic (entropic) formation of organic-inorganic coacervates with improved mechanical strength. We seek to control and modify material properties and stimuli-responsive characteristics of hybrid coacervates, and to explore new practical applications of organic-inorganic coacervate complexes, i.e. (bio)separation, wastewater treatment, drug delivery, battery electrolyte and electrodes.

Molecular Exchange Monte Carlo. A Generalized Method For Identity Exchanges In Grand Canonical Monte Carlo Simulations, Mohammad Soroush Barhaghi

Wayne State University Theses

A generalized identity exchange algorithm is presented for Monte Carlo simulations in the grand canonical ensemble. The algorithm, referred to as Molecular Exchange Monte Carlo (MEMC), may be applied to multicomponent systems of arbitrary molecular topology, and provides significant enhancements in the sampling of phase space over a wide range of compositions and temperatures. Three different approaches are presented for the insertion of large molecules, and the pros and cons of each method are discussed. The performance of the algorithms is highlighted through grand canonical Monte Carlo histogram-reweighting simulations performed on several systems, including 2,2,4-trimethylpentane+neopentane, butane+perfluorobutane, methane+n-alkanes, and water+impurity. Relative …

Investigating The Use Of Class C Flyash-Based Geopolymer Cement As A Potential Alternative To Portland Cement To Seal Co₂ Storage Wells, Priyesh Parimal Jani

Masters Theses

"Capturing emitted carbon dioxide from the source of emission and storing it underground is one effective way to reduce the amount of CO₂ in the atmosphere and is called carbon capture and storage (CCS). For the successful CCS project, it is necessary to ensure long term storage of injected CO₂ inside these selected reservoirs. Portland cement used to cast wells in these reservoirs degrade in CO₂ environment and can create migration path for leakage of CO₂. The aim of this study was to provide a comprehensive review about the problem, to propose a new geopolymer …

Computational Fluid Dynamics Modeling Of Proppant Static Settling Velocity In High Viscosity Friction Reducers, Chen Yuan

Masters Theses

"In the current petroleum fracturing industry, it is necessary to understand the downhole migration and settling velocity of the proppant. If we can master this information well, it will be a great help to obtain effective propped fracture conductivity. In order to study the transport of proppants in the well, we used laboratory experiments and computer numerical simulations to compare the results to get a meaningful conclusion. We spent a lot of time building models on a powerful computer and comparing the experimental conclusions. We finally decided to use computational fluid dynamics (CFD) as the simulation platform, discrete phase method …

Gel Composition And Brine Concentration Effect On Hydrogel Dehydration Subjected To Uniaxial Compression, Xinrui Zhao

Masters Theses

"Gel treatment is a process that injects the gel into a reservoir to control the conformance and improve the sweep efficiency of injection fluids. At a certain pressure gradient, the gel dehydrates in a reservoir due to mechanical forces. This work evaluates the effects of the gel composition and brine concentration on gel dehydration under uniaxial compression. A sodium acrylate-co-acrylamide based gel cross-linked with N, N'-Methylenebisacrylamide (MBAA) was used for the study. The compression test is performed with a rheometer with a plate-plate geometry. The gel dehydration under pressure was measured to see how gel dehydration would be impacted by …

Diffusion Kinetics In Promising Adsorbents For Gas Capture Processes, Teresa Gelles

Masters Theses

"This reports the results of experimental studies aimed at characterizing the transport properties of promising adsorbents for various gas capture processes by the "zero length column" (ZLC) technique. ZLC was used to measure the intracrystalline diffusivities of single and binary components of ethane and ethylene in powder and pellet samples of paraffin-selective adsorbents Ni(bdc)(ted)_0.5 (Ni-BT) and ZIF-7 for the purpose of olefin/paraffin separation. Results show that binary gaseous systems result in intracrystalline diffusion time constants slightly lower than those in single component gaseous streams due to coadsorption effects. It was also found that ethylene diffusion was affected by surface …

Breaker Evaluation And Formation Damage Remediation Of Re-Crosslinkable Preformed Particle Gel (Rppg), Enze Zhou

Masters Theses

"Re-crosslinkable preformed particle gel (RPPG) is a newly developed preformed particle gel for improving sweep efficiency and oil recovery by blocking or reducing the conductivity of fractures and fracture-like channels or conduits. However, RPPG has the potential to plug the facilities or damage the formation if a treatment is not properly conducted.

This work presents the performance of selected oxidizing breakers on the degradation of RPPG. The influence of a few factors on the degradation process was investigated, including breaker type, breaker concentration, temperature, gel concentration, gel aging time, and gel size. Results indicate that breaker type, concentration, and temperature …

Developing A Model System Of Liquid Lubricants For Space Applications: Multiple Alkylated Cyclopentane In Alumina Enclosed Surface, Vidit Singh

Masters Theses

"Lubricants are substances used for reducing friction wear tear and energy losses between two moving bodies. For space applications, normal lubricants cannot be used as they cannot survive the harsh and demanding conditions of space. Multiple Alkylated Cyclopentanes (MACs) have been utilized as space lubricants in recent times with tremendous results. NASA uses the MACs for their missions in space, in particular 1,3,4- tri-(2-octyldodecyl) cyclopentane sold by Nye Lubricants under the name of Pennzane^TM.

In this research, an effort has been made to identify appropriate potential models for simulating Pennzane molecules and to develop MD simulation codes to …