December 2019 - Msepostdoc-list

Seminar Notice for Cole Davis Wednesday, Dec. 11, 9:30 a.m., in ARMS 1021"Formation and Stability of Surfactant-Stabilized, Spontaneous, Oil-in-Water Emulsions in Saline Environments"
by Son, Rosemary E 09 Dec '19

09 Dec '19

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Formation and Stability of Surfactant-Stabilized, Spontaneous, Oil-in-Water Emulsions in Saline Environments" By Cole R. Davis Purdue MSE Preliminary Exam Advisors: Professor Carlos J. Martinez and Professor Kendra A. Erk ABSTRACT Spontaneous emulsification provides a low energy alternative to forming nano-sized emulsions in pharmaceuticals, enhanced oil recovery, detergency, and more. Although this method can be advantageous, spontaneous emulsification can be problematic in systems where oil and water mixtures are undesirable. These systems include wastewater and can introduce harmful oils (e.g., aromatics) into the environment. Literature involving spontaneous emulsification provides mechanisms for how these emulsions form, but little is done to precisely control the occurrence or rate of spontaneous emulsification. Furthermore, few papers exist that include the presence of salts during emulsification, which is highly relevant to many wastewater systems including bilge water. This study investigates the formation of spontaneous oil-in-water emulsions in saline environments and proposes the following hypothesis: the presence of salts found in seawater will act to promote spontaneous emulsification and may increasing the stability of surfactant-stabilized oil-in-water emulsions. To test this hypothesis, dynamic light scattering will be used to quantify the rate of emulsification for a variety of surfactant-oil-saltwater mixtures. Salinities will be selected based on calculated optimal salinity values where the hydrophilic lipophilic difference (HLD) is zero. Surfactant concentrations will also vary according to their respective critical micelle concentrations (CMCs) at different salinities to test the need for the presence of surfactant micelles during spontaneous emulsification. This work will provide a deeper understanding on the formation and stability of spontaneous emulsions in saltwater systems with the goal of building a model, based on the HLD model, that can be used to predict and ultimately prevent spontaneous emulsification in wastewater systems. Date: Wednesday, December 11, 2019 Time: 9:30 A.M. Place: ARMS 1021

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Seminar Reminder for Michael Park's Preliminary Exam. Seminar, Tuesday, Dec. 10, at 9:00 a.m., in ARMS 1021 "Perovskite Nickelate ReRAM for Next Generation Memory"
by Son, Rosemary E 09 Dec '19

09 Dec '19

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Perovskite Nickelate ReRAM for Next Generation Memory" By Michael Taejoon Park Purdue MSE Preliminary Exam Advisor: Professor Shriram Ramanathan ABSTRACT The traditional semiconductor memory device scaling based on Moore's law is reaching fundamental limits. To overcome this scaling limit, alternative ways have been explored. Among potential candidates, Resistive Random-Access Memory (ReRAM) is one of great interest due to its scalability, low power consumption, and fast programming speed compared with the existing memory technology. ReRAM device uses materials including transition metal oxides that switch the resistance when an external bias is applied. This report summarizes the classification of ReRAM device based on resistive switching characteristics and the underlying mechanisms. Following that, perovskite rare-earth nickelates (RNiO3) as a promising candidate for ReRAM device are reviewed. These materials undergo distinctive metal-insulator phase transition caused by charge disproportionation when temperature decreases. In addition, electron doping through hydrogenation induces a more dramatic phase transition of the same nickelate system which give rise to resistance change by several orders of magnitude. The multi-level resistance states of hydrogen doped RNiO3 could be modulated by electric fields and it provides the potential for emerging memories. Date: Tuesday, December 10, 2019 Time: 9:00 A.M. Place: ARMS 1021

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Seminar Reminder for Ryan Szeto's Preliminary Exam. Seminar Tuesday, Dec. 10, at 9:30 a.m., in ARMS B071. "Investigation of Particle Properties on the Effect of Yield Stress of a Biomass Slurry"
by Son, Rosemary E 09 Dec '19

09 Dec '19

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Investigation of Particle Properties on the Effect of Yield Stress of a Biomass Slurry" By Ryan Szeto Purdue MSE Preliminary Exam Advisors: Professor John A. Howarter and Kendra A. Erk ABSTRACT Corn stover is a lignocellulosic feedstock material that can be used for bioethanol production and alleviates problems with current first-generation biofuels. Despite the great promise of corn stover for biofuel conversion, it is hindered by its recalcitrant nature and high yield stress which is the stress necessary for flow to occur. Incorporating enzymes or dilute acid pretreatment is known to decrease the yield stress and viscosity of the system and increase pumpability. Though it is known that the value of yield stress decreases with processing, its effects on particle properties is poorly understood for corn stover particles. It is proposed that the critical parameters controlling yield stress are dependent on a maximum packing fraction that can change depending on particle shape and size distribution. The impact of aspect ratio, modulus, and roughness are explored for the effect on the value of yield stress. Characterization of these properties will give better insight and understanding of how corn stover particles are modified as a result of processing. Date: Tuesday, December 10, 2019 Time: 9:30 A.M. Place: ARMS B071 School of Materials Engineering Purdue University Neil Armstrong Hall of Engineering 701 West Stadium Ave. Room 2200 West Lafayette, IN 47907 765-494-4105 [PU150]

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Seminar Notice for Shukai Yao's Preliminary Exam. Wednesday, Dec. 11, at 8:30 a.m., in ARMS B071. "Quaternary Cu2ZnSn(S, Se)4 Absorber Materials for Photovoltaic Applications"
by Son, Rosemary E 09 Dec '19

09 Dec '19

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Quaternary Cu2ZnSn(S,Se)4 Absorber Materials for Photovoltaic Applications" By Shukai Yao Purdue MSE Preliminary Exam Advisor: Professor Peilin Liao ABSTRACT Cu2ZnSn(S,Se)4 (CZTSSe) has drawn wide interest in the photovoltaic (PV) community for the last decade as the material components are environmental friendly and abundant on earth, and it has tunability in terms of band gap ranging from 1.0 to 1.5 eV. However, the CZTSSe-based solar cell needs to be improved with respect to energy conversion efficiency (~12%). The inherent elements complexity of quaternary CZTSSe system has raised difficulties in fabricating samples with a high quality. The underlying origin of the difficulties is manifested by two main factors: (i) secondary phases and (ii) point defects. Suppressing their formation will decrease the band alignment fluctuations and the carrier recombination, enhancing the PV performance. Combining the current experimental and computational studies, this review discussed the crystal structure, electronic structure, secondary phases and points defects of CZTSSe, exploring the possible future work on optimizing this PV material. Date: Wednesday, December 11, 2019 Time: 8:30 A.M. Place: ARMS B071

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Winter Break Lab Access
by MSE Safety 09 Dec '19

09 Dec '19

Hello MSE Researchers, Happy holidays! This is a reminder to plan accordingly for upcoming holiday break and winter recess. Please note the following: * A note to undergrads and grad mentors: Please note that no undergrads are allowed to access any lab space EVEN WITH A GRAD STUDENT during the holiday break (Monday Dec. 16- Monday Jan. 13). Undergraduate lab access will be turned off starting at 5 pm on Friday Dec. 13th and return on 8 am on Monday Jan 13th. * A note to graduate researchers and post-docs: Please note that most faculty and staff members will not be here during winter recess (Dec. 23th-Jan. 2). While grad students and post-docs are permitted to do lab work during winter recess, please exercise extra caution while performing tasks. It is suggested that you work in pairs in case of an accident. HF use over winter recess is prohibited. If you have any questions, please let me know. Happy Holidays & Safe Travels, Jenni Fifer Safety & Mechanical Testing Lab Technician Materials Science & Engineering Purdue University Phone: 765-494-9718 Email: fiferj(a)purdue.edu<mailto:fiferj@purdue.edu>

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Seminar Reminder for Jose Waimin's Preliminary Exam. Seminar, Monday, Dec. 9, at 8:00 a.m., in ARMS 1021. "Impedimetric Measurement of Polymer Degradation for Non-invasive Assessment of Microbial Activity"
by Son, Rosemary E 06 Dec '19

06 Dec '19

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Impedimetric Measurement of Polymer Degradation for Non-invasive Assessment of Microbial Activity" By Jose F. Waimin Purdue MSE Preliminary Exam Advisor: Professor Rahim Rahimi ABSTRACT As the demand for food products results in an unsustainable stress on our soils, under- standing the effects of microbial activity could pave the pathway towards more sustainable agriculture. Bacteria play essential roles in soil including decomposing materials as well as mineralizing nutrients from fertilizers into forms that crops can use. Current methods for microbial activity detection require high cost, specialized technicians, soil sampling, and lab culturing. These limitations make in-field detection hard to attain. Electrochemical sensors provide a solution for low-cost, large-scale deployment of sensors that can be easily integrated with wireless modules. This work demonstrates the feasibility of real-time microbial activity assessment by non-invasively monitoring of the biodegradation of polymers through a differential impedance method. This concept was tested by measuring the degradation of a Cellulose Acetate (CA) film in the presence of Pseudomonas aeruginosa, a decomposing microorganism commonly found in soil. The growth in microbial concentration was measured as a distinct decrease in impedance, with a sensitivity of 156 Ω/log[CFU/mL]. Further applications of this technology will include using different active materials to, not only measure degradation, but also other forms of microbial activity such as metabolic or enzymatic activity. Date: Monday, December 9, 2019 Time: 8:00 A.M. Place: ARMS 1021

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MSE Seminar: N. Jackson, Argonne National Laboratory, Dec. 12, 3:30 pm
by Stacey, Lisa A 06 Dec '19

06 Dec '19

Your attendance is appreciated for Materials Engineering's invited guest, Dr. Nicholas Jackson's seminar next Thursday, December 12th, 3:30-4:30 pm in ARMS B071. ________________________________ [cid:image002.png@01D5AC32.667D07F0] Regards, Lisa Stacey Administrative Assistant to the Department Head Purdue University School of Materials Engineering Neil Armstrong Hall of Engineering 765/494-4095 staceyl(a)purdue.edu<mailto:staceyl@purdue.edu> [https://www.purdue.edu/brand/images/Purdue_University-150_Years_of_Giant_Le…]

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Seminar Reminder for Anthony Becerril's Preliminary Exam. Seminar, Friday, Dec. 6, at 2:30, in ARMS 1109. "Destructive and Nondestructive Testing Methodologies in Concrete Durability"
by Son, Rosemary E 06 Dec '19

06 Dec '19

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Destructive and Nondestructive Testing Methodologies in Concrete Durability" By Anthony P. Becerril Purdue MSE Preliminary Exam Advisor: Professor Jeffrey P. Youngblood ABSTRACT Cementitious materials are one of the oldest technologies to exist and are used in most products and infrastructures such as roads, parking lots, buildings and more. Although an old technology, cementitious material production has not decreased and has had a static period of improvement in sustainability. The ongoing production rises concerns due to its environmental impact due to global warming and the thinning of the atmosphere. As of 2018, cement production is responsible for 8% of global C02 emissions. The use of sustainable, renewable materials is critical in cement research to significantly reduce the amount of carbon dioxide contributing to global warming. Compressive strength has historically has been tested to predict durability, but extensive reasons have shifted the focus more towards extensive durability testing. Some standards are considered Destructive Testing (DT) methods where tested samples are destroyed in the testing process and hence not available for further testing. DT methods are reliable in indicating durability mainly through strength testing. Additionally, there have been development of Nondestructive Testing (NDT) methods to extend usage of samples for determining durability. Although NDT preserve samples, there are arguments about the reliability of NDT over DT. Numerous DT and NDT standards evaluate cement performance through analysis of main parameters such as strength, durability, permeability, porosity and more3. Additionally, additives have been used to improve cement durability such as supplementary cementitious materials (SCM), chemical admixtures, and nanomaterials have been widely used and developed. Previous literature has shown that cellulose nanocrystals when used as an additive improves cement performance through flexural strength, microstructure enhancement, and an increase in degree of hydratioll4. With the increased demand for more sustainable cement production, cellulose as an additive for cement provides a resource that is renewable, biodegradable, while also improving environmental, economic, and health impacts. In this work, concrete durability testing with DT and NDT methods will be compared to address challenges, such as reliability, in concrete research and industry practices. Additionally, cellulose nanocrystals as an additive in cement production will be reviewed. Lastly, current research on cement paste durability advancement with nano-additives will be addressed. Date: Friday, December 6, 2019 Time: 2:30 P.M. Place: ARMS 1109

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