November 2021 - Msepostdoc-list

Preliminary Exam Seminar December 3, Friday, 8:30 AM by Webex
by Morgan, Yuan-Yu Karen 19 Nov '21

19 Nov '21

Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR "Magnetic Field-assisted Anisotropic Polymer-based Piezoresistive Composite with Tunable Electrical and Mechanical Properties" By Nagarpita Moka Vidyanag Purdue MSE Preliminary Exam Advisor: Professor Mukerrem Cakmak ABSTRACT Polymer composites that exhibit piezoresistive behavior have been actively sought in the emerging field of flexible electronics as a replacement for traditional metallic or semiconductor-based devices. A particularly attractive area of application for these flexible piezoresistors is their use as pressure sensors due to their ability to endure large mechanical strains (stretchability) while retaining their electrical conductivity. Magnetic field manipulation of metallic particles with high magnetic susceptibilities (Fe, Co, Ni) is an effective technique to fabricate anisotropic composites by forming pearl-chain columns that drastically reduce the concentration of fillers required to produce enhanced piezoresistive performance. The alignment of particles in the through-thickness direction creates induced percolation thereby resulting in a lightweight, optically transparent, and conformable composite. This review aims to provide an insight into the research advances in the development of flexible piezoresistive composites via a mechanistic understanding of the structural evolution of column structures during the alignment process. Various strategies employed to improve column morphology by tuning processing conditions are explored with the foresight of implementing it on roll-to-roll manufacturing technology. Finally, the influence of the mechanical modulus of the viscoelastic polymer matrix on the final composite property is also addressed to highlight the importance of careful design procedures that need to be adopted to maximize the sensitivity and stability of these pressure sensing elements. Date: December 3, 2021 Time: 8:30 AM Place: Webex---https://purdue.webex.com/meet/cakmak Yuan-Yu Karen Morgan,Ph.D. Academic Advisor-Graduate Program School of Materials Engineering Neil Armstrong Hall of Engineering, Room 2217 765-494-4103 ymorgan(a)purdue.edu<mailto:ymorgan@purdue.edu>

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Preliminary Exam Seminar Thursday, November 2, 9 AM
by Morgan, Yuan-Yu Karen 18 Nov '21

18 Nov '21

Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR "Mechanisms and Approaches to Improve Oxidation Resistance of Transition Metal Nitrides" By Yizhi Zhang Purdue MSE Preliminary Exam Advisor: Professor Haiyan Wang ABSTRACT Transition metal nitrides (TMN) have attracted interest from scientists for many years due to their unique optical, electrical, thermal, and mechanical properties. TiN and ZrN have already been used as commercial hardness coating for cutting tools. However, most transition metal nitrides coating will be oxidized and lose their coating function at high temperatures. (e.g. TiN coating is oxidized at as low as 600ºC) This phenomenon not only increased the difficulty to produce high-quality TMN coating but also limited the further applications of transition metal nitrides. To explore further applications, it is necessary to find a suitable way to improve the oxidation resistance of transition metal nitrides. In this review, the oxidation mechanism and previous approaches to improve the oxidation resistance will be discussed, as well as the existence challenge and promising future work. Date: December 2, 2021 Time: 9:00 AM WebEx: https://purdue.webex.com/purdue/j.php?MTID=m9be27b91e7e1fdc0f58f371a75fc9ffb Yuan-Yu Karen Morgan,Ph.D. Academic Advisor-Graduate Program School of Materials Engineering Neil Armstrong Hall of Engineering, Room 2217 765-494-4103 ymorgan(a)purdue.edu<mailto:ymorgan@purdue.edu>

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Final Defense Seminar, Thursday, December 2, at 2 PM
by Morgan, Yuan-Yu Karen 18 Nov '21

18 Nov '21

Please consider attending: MATERIALS ENGINEERING SEMINAR "Improving the Mechanical Properties of Cold Spray Metalized Polymers" By Jung-Ting Tsai Purdue MSE Ph.D. Final Exam Advisors: Professor David Bahr ABSTRACT Cold sprayed metallic coatings on polymers provide the benefits of a non-traditional manufacturing solution. However, the process steps for formulating the coating layer often require trial and error to secure an optimal coating. Many common testing methods for interface adhesion and the coating's mechanical performances only give semi-quantitative measurements. As a result, it's challenging to build the connection between the process-structural relationships of the coated materials. This work established a process simulation framework and created an experimental material characterization method to quantify the mechanical strength of cold spray coatings onto polymer substrates. Particle velocity, mass flow rate, and powder flowability were measured from a low-pressure cold spray system. Increases in mass flow rate are a consequence of good powder flowability. The developed tools and the measurement devices allow quantifying the powder flowability to deposition efficacy in cold spray coatings. Knowing the experimental parameters, we utilized a three-network polymer model based on high strain-rate impact tests to simulate the nonlinear time-dependent response of polymer deformation during the cold spray impact with both rigid and deformable particles. The particle's material properties, velocity, and size were systematically studied to obtain various responses from the finite element analysis of the polymer deformation. The numerical results were mapped into diagrams and validated with the experimental results of cold spraying Cu and Al2O3 powders. The cold spray process controls the adhesion strength between the coating and the substrate but does create a relatively wide distribution of film thickness and properties. Therefore, a mechanical test fixture was built to track electrical conductivity and coating fragmentation during tensile testing of metalized polymers. A modified Weibull model used the crack density, fragment length, and the measured specimens strength/strain to calculate the coated strength distribution at a fixed crack density and the mean strength as a function of fragment length. The specimens coated between 74 μm - 120 μm show an interfacial shear strength between 25 - 53 MPa, while 23 μm - 37 μm show adhesion energy between 2.3-7.9 J/m2. Cold sprayed dual-layer (Sn/Cu), and electroless plated specimens were built successfully using the information from the process simulation model. Cold spray coating increases the engineering performance of the coated substrate. The studies have demonstrated selecting appropriate process parameters for multiple metal/polymer combinations to achieve a successful coating. Date: Thursday, December 2, 2021 Time: 2:00 P.M. Webex: https://purdue.webex.com/join/dfbahr Yuan-Yu Karen Morgan,Ph.D. Academic Advisor-Graduate Program School of Materials Engineering Neil Armstrong Hall of Engineering, Room 2217 765-494-4103 ymorgan(a)purdue.edu<mailto:ymorgan@purdue.edu>

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Preliminary Exam Seminar, Thursday, December 2, 9 AM by Webex
by Morgan, Yuan-Yu Karen 18 Nov '21

18 Nov '21

Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR "Mechanisms and Approaches to Improve Oxidation Resistance of Transition Metal Nitrides" By Yizhi Zhang Purdue MSE Preliminary Exam Advisor: Professor Haiyan Wang ABSTRACT Transition metal nitrides (TMN) have attracted interest from scientists for many years due to their unique optical, electrical, thermal, and mechanical properties. TiN and ZrN have already been used as commercial hardness coating for cutting tools. However, most transition metal nitrides coating will be oxidized and lose their coating function at high temperatures. (e.g. TiN coating is oxidized at as low as 600ºC) This phenomenon not only increased the difficulty to produce high-quality TMN coating but also limited the further applications of transition metal nitrides. To explore further applications, it is necessary to find a suitable way to improve the oxidation resistance of transition metal nitrides. In this review, the oxidation mechanism and previous approaches to improve the oxidation resistance will be discussed, as well as the existence challenge and promising future work. Date: December 2, 2021 Time: 9:00 AM WebEx: https://purdue.webex.com/purdue/j.php?MTID=m9be27b91e7e1fdc0f58f371a75fc9ffb Yuan-Yu Karen Morgan,Ph.D. Academic Advisor-Graduate Program School of Materials Engineering Neil Armstrong Hall of Engineering, Room 2217 765-494-4103 ymorgan(a)purdue.edu<mailto:ymorgan@purdue.edu>

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Preliminary Exam Seminar Wednesday, December 1, 8 AM
by Morgan, Yuan-Yu Karen 17 Nov '21

17 Nov '21

Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR “Radiative Properties of Ultra-High Temperature Ceramics: ZrB2-SiC” By Abdullah Saad Purdue MSE Preliminary Exam Advisor: Professor Rodney Trice and Professor Carlos Martinez ABSTRACT Developing vehicles that can fly at a speed more than Mach 5 is essential for next-generation hypersonic aircraft. During hypersonic flight, a significant amount of energy is transferred to the vehicle leading edge, heating it to a temperature greater than 1800℃. It is necessary to reduce this high surface temperature of leading edges and this reduction in temperature can be achieved by radiating heat away from the surface. The relevant material property is emissivity, with a value approaching one desired. To protect the leading edge of hypersonic vehicle from extreme heating, it is important to find a class of materials that can withstand high temperatures and have enhanced radiative property. Ceramics are suitable for high-temperature applications since they usually melt at higher temperatures than metals and alloys. The potential class of materials to be used in extreme hypersonic environments is known as ultra-high temperature ceramics (UHTC). Usually, borides and carbides of transition materials are considered UHTC because of their high melting points, oxidation, and ablation resistance. Among them, ZrB2 has been investigated as a promising UHTC material for the hypersonic application. However, ZrB2 alone is not an ideal candidate because of its low fracture toughness and low oxidation resistance at high temperatures over 1400℃. To overcome such shortcomings, SiC is incorporated into ZrB2, improving the densification of ZrB2 and its oxidation resistance. More importantly, several studies have been performed to investigate the radiative properties of ZrB2-SiC composites and to discover methods to tailor the emissivity of this potential candidate. Ultimately, the outcome of these investigations is to find a material system which will be capable of radiating energy at high temperatures with maximum efficiency and will have improved ablation properties, and oxidation resistance. Date: Wednesday, December 1, 2021 Time: 8:00 AM WebEx: https://purdue.webex.com/meet/rtrice Yuan-Yu Karen Morgan,Ph.D. Academic Advisor-Graduate Program School of Materials Engineering Neil Armstrong Hall of Engineering, Room 2217 765-494-4103 ymorgan(a)purdue.edu<mailto:ymorgan@purdue.edu>

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Preliminary Exam Seminar, December 1, Wednesday at 9 AM
by Morgan, Yuan-Yu Karen 17 Nov '21

17 Nov '21

Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR "Gamma-irradiation Resistant and Inkjet Printable Potentiometric pH sensors and Their Reference Electrodes" By Bingyuan Zhao Purdue MSE Preliminary Exam Advisor: Professor Alexander Wei and Professor Lia Stanciu ABSTRACT Flexible electrochemical sensors have emerged as a new generation of sensors to substitute for traditional sensors, due to their low-cost, ease of fabrication, and biocompatibility. However, given the huge application potential of SC-ISEs in biomedical processes and clinical analysis applications, few work discussed the sterilization compatibility of these flexible sensors, which is of great significance before launching to the market. In addition, to make them low-cost and easy-to-scale-up, a easier way instead of conventional lithography techniques needs to address. The lack of these two studies motivates us to develop new SC-ISEs and their reference electrodes that can maintain their ffunctionalities after sterilization process; and use inkjet printing to produce the electrodes which is applicable for large scale manufacturing processes. Date: December 1, 2021 Time: 9:00 AM Place: Webex--https://purdue.webex.com/meet/alexwei Yuan-Yu Karen Morgan,Ph.D. Academic Advisor-Graduate Program School of Materials Engineering Neil Armstrong Hall of Engineering, Room 2217 765-494-4103 ymorgan(a)purdue.edu<mailto:ymorgan@purdue.edu>

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Final Exam Seminar, Tuesday, November 30, at 11:30 AM
by Morgan, Yuan-Yu Karen 16 Nov '21

16 Nov '21

Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR "The Influence of Print Layer Orientation on the Mechanical Properties of SiC and Cf/SiC CMCs Formed via Direct Ink Writing" By Kyle Cox Purdue MSE M.S. Final Exam Advisors: Professor Rodney Trice and Professor Jeff Youngblood ABSTRACT Silicon carbide is a useful monolithic and matrix ceramic due to its excellent mechanical properties and corrosion/oxidation resistance at high temperature. This makes it an attractive material for use in advanced applications, such as aircraft engines and high-speed flight. In this study, additively manufactured monolithic SiC and Cf/SiC CMCs, processed via direct ink writing (DIW) of a 53 vol% colloidal suspension, achieved >96% theoretical density through pressureless sintering. When present, fibers are aligned in the direction of the print path. Five different print paths were studied, including a 0o path, 90o path, 0/90o path, 0/15/30/45/60/75/90o path, and 0/30/60/90/60/30/0o path. Four-point bend testing was performed to determine flexural strength and Weibull analysis was performed. Strengths were highest for the 0o print path. The characteristic strength, σo, of this print path was 375 MPa with a Weibull modulus of 7.4 for monolithic SiC and a σo of 361 MPa with a Weibull modulus of 10.7 for Cf/SiC. Weibull modulus was greater for Cf/SiC samples compared to identically printed monolithic SiC samples. SEM and optical microscopy were used to analyze printed parts which showed a high degree of fiber alignment in the direction of the print. Fiber pullout was observed on the fracture surface, as well as intragranular fracture. Date: Tuesday, November 30, 2021 Time: 11:30 A.M. Place: by Webex https://purdue.webex.com/meet/rtrice Yuan-Yu Karen Morgan,Ph.D. Academic Advisor-Graduate Program School of Materials Engineering Neil Armstrong Hall of Engineering, Room 2217 765-494-4103 ymorgan(a)purdue.edu<mailto:ymorgan@purdue.edu>

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Final Exam Seminar, Monday, November 29, 10 AM
by Morgan, Yuan-Yu Karen 15 Nov '21

15 Nov '21

Please consider attending this seminar: MATERIALS ENGINEERING SEMINAR "Impact of Dynamic Ageing on The Formation and Stability of Model Bilge Water Oil-in-Water Emulsions" By Rina Sabatello Purdue MSE M.S. Final Exam Advisors: Professor Carlos Martinez and Professor John Howarter ABSTRACT Ships, including those in the US Navy, collect oily wastewater in their bilge due to onboard cleaning and mechanical operations. Oil-in-water emulsions (O/W) are present in bilgewater, and their filtration is difficult due to surfactants provided by cleaning products. Despite cleaning efforts, over 457,000 tons of oil are discharged into the ocean every year. An often overlooked aspect of bilgewater emulsions is their evolution, as the ship's movement at sea provides extra energy that can further emulsify the collected oil. This work aims to understand the effects of motion on model bilgewater emulsions by tracking their evolution in dynamic (rocking motion) and static conditions. The model bilgewater emulsion comprises mineral oil, deionized water with 0.42 M NaCl to mimic the salinity of seawater and sodium lauryl ether sulfate and Triton X-100, as commonly found anionic and nonionic surfactants, respectively. A rocker is used to simulate a ship motion; 15 mL of emulsion were placed in 50 mL centrifuge tubes to mimic partially filled bilgewater tanks. Emulsions were characterized via laser diffraction and optical microscopy. Model bilgewater emulsions with either SLES or Triton X-100 at concentrations above 100 ppm and 500 ppm, respectively, show long-term stability in static (no-rocking) conditions up to 20 days of observation. These concentrations represent the minimum surfactant concentration needed to obtain stable emulsions under static conditions. Under dynamic conditions, the minimum surfactant concentration to obtain stable emulsions increases to 500 ppm and 1000 ppm for SLES and Triton X-100, respectively. These results mean that the ship motion can induce drop coalescence in unstable emulsions with lower surfactant concentrations. However, the drop size distributions for stable emulsions under dynamic conditions show further emulsification as the average drop size decreases. The ship motion can help further reduce the size of the emulsion drops to diameters < 2.8 µm, which are significantly harder to filter out using current methods. A bilgewater tank partially filled will likely show a higher amount of sloshing than a filled one. To understand the effects of bilgewater storage volume on emulsification, a series of dynamic experiments were carried out with samples that contained up to 100% of the centrifuge tube volume occupied by the model bilge water emulsion. Even when 100% of the centrifuge volume is occupied and sloshing is eliminated, the oil moves due to density differences, and the shear stress between fluids can induce the generation of drops < 2.8 µm. In summary, this work shows that the ship motion provides enough energy for emulsification once a minimum surfactant concentration is reached regardless of the volume of emulsion stored in the tanks. The data suggests that the best way to mitigate stable bilgewater emulsion formation is by reducing surfactant concentration Date: Monday, Nov 29, 2021 Time: 10:00 A.M. Place:https://purdueedu.zoom.us/j/97465163370?pwd=cW1JdFBCdE9maTRmN3ZJMUZHWmxsQT09 Yuan-Yu Karen Morgan,Ph.D. Academic Advisor-Graduate Program School of Materials Engineering Neil Armstrong Hall of Engineering, Room 2217 765-494-4103 ymorgan(a)purdue.edu<mailto:ymorgan@purdue.edu>

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MSE 690 Nov 15 Karen Winey, ARMS 1010, 3:30 PM
by Ku Blanco, Aury Y 12 Nov '21

12 Nov '21

Good afternoon, See you at 3:30 in ARMS 1010 this coming Monday for Prof. Karen Winey's visit to campus. [cid:image003.jpg@01D7D7D6.10274060] Best, Aury Ku she/her/hers Administrative Assistant Materials Engineering Neil Armstrong Hall of Engineering 701 W Stadium Ave, ARMS 2300 West Lafayette, IN 47906 o: 765-494-4100 f: 765-494-1204

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FW: Chemistry Analytical Seminar, Tuesday, November 16, 2021
by Son, Rosemary E 12 Nov '21

12 Nov '21

From: Hanna, Thomas J Sent: Friday, November 12, 2021 2:34 PM To: Mechanical Engineering Graduate Office <megradoffice(a)purdue.edu>; Elwell, Cathy L <celwell(a)purdue.edu>; Golden, Matt <goldenm(a)purdue.edu>; Ricksy, Jennifer R <jricksy(a)purdue.edu>; Zimmerman, Nicole K <nzimmerm(a)purdue.edu>; Son, Rosemary E <son39(a)purdue.edu>; Johnson, Beverly J <bevjohnson(a)purdue.edu>; Delaney, Morgan J <mdelane(a)purdue.edu> Subject: Chemistry Analytical Seminar, Tuesday, November 16, 2021 Please distribute the attached Analytical Seminar announcements for the seminar on Tuesday, Nov 16, 2021 in your respective areas. Thank you, Tom Hanna Administrative Assistant to: Analytical Division of Chemistry Professors Claridge, Kenttämaa, A. Laskin, J. Laskin, McLuckey, Simpson, Wirth, C. Zhang Organic Division of Chemistry Professors Axelrod, Chmielewski, Lipton, Mao, Mei, Sintim Department of Chemistry BRWN 5171A Purdue University 560 Oval Drive West Lafayette, IN 47907-2084 hanna9(a)purdue.edu<mailto:hanna9@purdue.edu> 765-494-5267

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